Sometime in the near future it probably will be shown that the older
urban areas of the United States have been rendered more or less
uninhabitable by the millions of tons of poisonous industrial lead
residues that have accumulated in cities during the past century.
Clair C. Patterson, National Academy of Sciences (1980)
Plot of Temporal Variation in Atmospheric Soil and Lead in Detroit - 2001-2009
Scatterplot with median splines of weather adjusted air lead and air soil in time (daily). Weather-adjusted air Pb and soil estimates (µg/m3) are graphed on the daily time-step, fitting distributions of air Pb and soil values with median splines.
Plot of Temporal Variation in Atmospheric Lead and Children's Blood Lead in Detroit - 2001-2009
Weather-adjusted air Pb (µg/m3) and blood Pb (µg/dL) by age group. Average monthly child blood Pb levels adjusted by local weather conditions, child gender, method of blood draw, and census tract fixed effects
Source - SCERP Monograph Series no. 12, The U.S-Mexican Border Environment:
Integrated Approach to Defining Particulate Matter Issues in the Paso del Norte
Region.
The Emerging Paradigm About The Cause of Urban Lead Poisoning
The emerging lead poisoning paradigm is that chronic urban lead poisoning is caused by exposure to lead contaminated soil (contaminated from past leaded gasoline emissions and exterior lead paint) that is tracked into the interior of homes by shoes(Hunt et al., 2006)and the feet and fur of family pets and exterior urban soil that is re-suspended into the atmosphere where it penetrates interiors of homes and settles on interior contact surfaces(Layton and Beame, 2009)(Laidlaw and Filippelli, 2008). Children are also exposed to lead via direct ingestion of soil outdoors. Chronic urban lead poisoning can also be caused by exposure to lead paint particles. Sometimes, children are exposed to lead originating from BOTH lead paint particles AND from exterior lead contaminated soil dust. Children are primarily exposed via hand to mouth activity (thumb sucking). Acute lead poisoning is probably caused by ingestion of interior and exterior lead paint that has chipped or via ingestion of a large dose of soil with high lead concentrations.
Based upon the table above, it should be easily understood that if the exterior soils are contaminated with Pb, the interior
house dust will be contaminated with Pb as well.
Synchrotron Analysis Studies Supports Hypothesis That Pb in Outdoor Soil Is Significant Contributor to INDOOR dust Pb
The blood lead incidence rates in most large urban areas of the United States are probably similar to those shown on the blood lead incidence maps of Detroit, Milwaukee, and Cleveland (below).
The National Health and
Nutrition Examination Survey (NHANES) III 1999-2002
database indicates that approximately 2.4 million children
have blood Pb levels between 5 and 9.9 microgram/deciliter (Iqbal et al.,
2008) and that within that population of 1-'5-year olds
with blood Pb levels of 5 microgram/deciliter or higher, the prevalence
was 47% for non-Hispanic Black children, 28% for Mexican
American children, and 19% for non-Hispanic White children
(Bernard, 2003). The fact that children of color are
nearly 4 times more likely than white children to have
blood Pb levels between 5 and 10 microgram/deciliter (and 13 times
more likely to have blood Pb levels above 20 microgram/deciliter; Bernard
and McGeehin, 2003) raises concerns about social justice
and the long-term health of these children.
New Orleans Soil Pb Blood Pb Dose Response - Most Recent
Lanphear et al. (1998): increasing soil lead concentration from background to 400 micrograms/g was estimated to produce an increase of 11.6% in the percentage of children estimated to have a blood lead level exceeding 10 micrograms/dL.
Malcoe et al. (2002): Logistic regression of yard soil lead >165.3 mg/kg (OR, 4.1; CI, 1.3-12.4) were independently associated with BPbs greater than or equal to 10 microg/dL.
Texas Dept. of Health (2004): Using large database from El Paso Area, study found an odds ratio 4.5 (1.4, 14.2)for the relationship between a 500 ppm increase in soil lead and blood lead level > 10 ug/dl.
Maisonette (1997): yard soil remediation showed the strongest association with changes in blood lead levels. This variable was found to be a protective factor for elevated blood lead levels in children (odds ratio, 0.28; confidence interval, 0.08-0.92).
Lucchini, RG, S Zoni, S Guazzetti, E Bontempi, S Micheletti, K Broberg, G Parrinello and DR Smith. 2012. Inverse association of intellectual function with very low blood lead but not with manganese exposure in Italian adolescents. Environmental Research http://dx.doi.org/10.1016/j.envres.2012.08.003.
Children's Blood Lead Levels Also Display Strong Seasonal
Variations With Peaks Generally in the Summer or Autumn When Soils Are
Dry and Prone to Resuspension
A conceptual model of child BPb seasonal Pb poisoning is suggested.
Lead from multiple sources has accumulated in soils of urban
environments. The seasonal resuspension of Pb-contaminated soil in
urban atmospheres appears to be controlled by soil moisture and climate
fluctuations. This study
(Laidlaw et al., 2005)indicates that
higher urban atmospheric Pb loading rates are experienced during
periods of low soil moisture and within areas of Pb-contaminated
surface soils. Children and adults living in urban areas where surface
soils are contaminated with Pb may become exposed through indoor and
outdoor inhalation of Pb dust and ingestion of Pb deposited within
homes and outdoor surfaces. Because resuspension of Pb from
contaminated soil appears to be driving seasonal child BPb
fluctuations, concomitantly, we suggest that Pb-contaminated soil in
and of itself may be the primary driving mechanism of child BPb
poisoning in the urban environment.
Laidlaw et al.'s (2005) model used in the three cities above was independently replicated in Milwaukee, Wisconsin in an unpublished court case
Soil Lead is a Major Source of Atmospheric Lead via Soil Re-suspension
Weather adjusted air Pb and air soil over time, including median spline fits, for Pittsburgh,
Detroit, Chicago and Birmingham.
Weather adjusted air lead versus air soil with linear fit for peak months (June, July, August, and
September) and non peak months (October through May) for Pittsburgh, Detroit, Chicago and Birmingham
combined.
This study also observed..."Atmospheric soil and lead aerosols are 3.15 and 3.12 times higher, respectively, during weekdays than weekends and Federal Government holidays, suggesting that automotive traffic turbulence plays a significant role in re-suspension of contaminated roadside soils and dusts."
Plot of Temporal Variation in Atmospheric Soil and Lead in Detroit - 2001-2009
Scatterplot with median splines of weather adjusted air lead and air soil in time (daily). Weather-adjusted air Pb and soil estimates (µg/m3) are graphed on the daily time-step, fitting distributions of air Pb and soil values with median splines.
Plot of Temporal Variation in Atmospheric Lead and Children's Blood Lead in Detroit - 2001-2009
Weather-adjusted air Pb (µg/m3) and blood Pb (µg/dL) by age group. Average monthly child blood Pb levels adjusted by local weather conditions, child gender, method of blood draw, and census tract fixed effects
Atmospheric Soils Are Resuspended With Peak Concentrations in the Summer and Autumn in the U.S.
It is believed that this process is resuspending urban lead contaminated soils in the summer and autumn.
The same summertime seasonality was observed for Total Suspended Particulates (TSP), Nickel, Iron and Sulfur in Esperance, Western Australia. Note summer in Esperance occcurs between November and February.
2.) Author:Nicholas E. Pingitore, Jr.1,2*, Juan W. Clague1, Maria A. Amaya2, Beata Maciejewska1, Jess J. Reynoso3
Title:Urban Airborne Lead: X-Ray Absorption Spectroscopy Establishes Soil as Dominant Source Source: PLOS One
Link
Despite the dramatic decrease in airborne lead over the past three
decades, there are calls for regulatory limits on this potent pediatric
neurotoxin lower even than the new (2008) US Environmental Protection
Agency standard. To achieve further decreases in airborne lead, what
sources would need to be decreased and what costs would ensue? Our aim
was to identify and, if possible, quantify the major species
(compounds) of lead in recent ambient airborne particulate matter
collected in El Paso, TX, USA.
Methodology/Principal Findings:
We used synchrotron-based XAFS (x-ray absorption fine structure) to
identify and quantify the major Pb species. XAFS provides
molecular-level structural information about a specific element in a
bulk sample. Pb-humate is the dominant form of lead in contemporary El
Paso air. Pb-humate is a stable, sorbed complex produced exclusively in
the humus fraction of Pb-contaminated soils; it also is the major lead
species in El Paso soils. Thus such soil must be the dominant source,
and its resuspension into the air, the transfer process, providing lead
particles to the local air.
Conclusions/Significance:
Current industrial and commercial activity apparently is not a major
source of airborne lead in El Paso, and presumably other locales that
have eliminated such traditional sources as leaded gasoline. Instead,
local contaminated soil, legacy of earlier anthropogenic Pb releases,
serves as a long-term reservoir that gradually leaks particulate lead
to the atmosphere. Given the difficulty and expense of large-scale soil
remediation or removal, fugitive soil likely constrains a lower limit
for airborne lead levels in many urban settings.
Urban Atmospheric Lead Is Associated with Particulate Matter Less Than 10 micron in Size (PM10)
Note the blood lead seasonal patterns below. Whatever drives these seasonal blood lead changes is the major driving force of urban blood lead poisoning.
USEPA Discussion - p. 45 "Exposure may increase
in the summer because of factors that include increased outdoor playing time, more
opening and closing of windows, increased hand-to-mouth activity, and drier leaded dust
that more easily enters homes."
What I found interesting about this study is that 78% of the blood lead
poisoning in the St. Louis study comes from children aged two to three, and 56% of the cases occurred
between June and September when sunshine was greatest. It would seem that if the Vitamin D hypothesis were true, there would not be
age dependent peaks (which are well known to be caused by mouthing behaviour) and suggests that blood lead seasonality is externally driven rather than
internally driven.
Note that the summertime atmospheric lead peaks coincided with the blood lead peaks. It is suggested that current blood lead
peaks are also caused by exterior atmosperic lead summertime peaks.
Homegrown Vegetables Are Another Exposure Pathway to Lead in Urban Soil
The recent movement towards cultivating homegrown vegetables, partly
due to the global financial crisis, poses risks due to the uptake of
lead in certain vegetables.
The following documents have been selected to educate the reader:
Solution - Remediation Precedent Set in New Orleans, Evansville and Omaha
1.) Method of Mielke et al.(2011) - New Orleans
"The soil emplacement was conducted by first spreading out a bright orange,
water pervious geotextile material to cover the original soil of the play area. The
geotextile layer prevents Pb-safe soil from mixing with the underlying original soil
and acts as a warning layer to anyone digging into soil. Soil was not removed from
the play areas in this project.
The Pb-safe soil was from the Bonnet Carré Spillway, located up-river from New
Orleans (U.S. ACE or Army Corps of Engineers). The alluvial soil, derived from the
sediments of the Mississippi River at the Bonnet Carré Spillway, has a median Pb content
of 5 mg/kg (Mielke et al., 2000). The Bonnet Carré soil was transported to the childcare
center and emplaced on top of the geotextile layer to a depth of at least 15cm(6 inches)."
Soil lead exposure reduction in the inner cities will improve health, increase students cognitive abilities and provide jobs, perhaps to inner-city residents.
Simple Non-toxic Way Forward
1.) Cut lawn as low as possible
2.) Lay down Bright Orange Geotextile
3.) Terraseeding (soil and seed mix)
-0r-
3.) Apply Topsoil Using Topsoil Slinger &
4.) Hydroseed During Spring
I recommend that soil covering efforts first be conducted in areas where there is a high prevalence of lead poisoning and where soil lead levels are high (triage). I would first focus on roadside soils (0-25m)within these areas and then continue until areas with high lead poisoning prevalence are covered (or funds permit).
Recommended Funding Mechanism To Cleanup Urban Soils
Small Gasoline Tax!
Call For Blood Lead Incidence Data Transparency
I strongly suggest that the new Obama government
publish child blood lead incidence maps of the top 50 cities in the U.S
by graphically displaying the location and all the blood lead
concentrations (>5 ug/dl, > 10ug/dl and >20 ug/dl) for the
previous 5 years, and updated yearly (see Detroit Blood Lead Incidence
Map Above).
The percentage of the children sampled should be boldly presented as
well. These maps should be available for all to see on one central
internet site.
The website would be registered with all the major search engines so
that anyone could locate the data.
This data is already available and could easily be put together in a
two month time period by someone experienced in GIS and the internet.
The funding cost would be extremely small.
Call For National Urban Soil Geochemical Risk Mapping Program
I suggest that the Obama administration use the United States
Geological Survey to conduct an urban soil geochemical risk mapping
program in the 50 largest cities in the
United States. I recommend the geochemical mapping methods be adopted fromthe British Geological Survey,
David L Johnson/colleagues at SUNY-ESF or Howard Mielke and colleagues at Tulane/Xavier.
The results should be placed online in one central location for anyone to view.
1.)The USEPA's 400 mg/kg soil guideline is not protective of
human health. A safe guideline would be about 75 to 100 mg/kg. The California draft soil lead guideline is 80 mg/kgLink. The Minnesota
(USA) soil lead guideline is 100 mg/kg and the Dutch guideline is 40
mg/kg. See the dose-response curves of Mielke and Johnson's soil
lead-blood lead ecological study design above. Risk assessments that
have argued to leave lead concentrations higher than 400 mg/kg (and
higher than 100 mg/kg) are deeply flawed and these areas will have to
be revisited when a lower guideline level is adopted by a bold USEPA,
if that ever happens.
2.) There is a glaring disconnect between the actions of the
USEPA and the CDC. While the USEPA is cleaning up 10's of thousands
of lead contaminated yards in Omaha and Evansville under the Superfund
program, the CDC does not have any money appropriated to the investigation
and remediation of contaminated soil and continue with the paradigm that
lead poisoning is caused primarily by lead paint. No money has been appropriated
by either the USEPA or the CDC for the investigation and remediation of non-Superfund
cities, of which many are just as contaminated as Omaha and Jacobsville
Conclusion
After 20 years of studying this problem, I conclude that it is probably more cost effective to move inner-city children (aged 0-7) to the lead free suburbs
than pay for extraordinarily massive remediation that is required of inner city soils, lead paints and lead water lines. These areas
could still be populated by adults. Money from a gasoline tax could fund the re-population. Its extraordinarily simple. Plot the locations where blood leads
exceed 5 micrograms per deciliter and move children and their families from these areas to the lead free suburbs.
Author:John L. Adgate, Robert D.
Willis, Timothy J. Buckley, Judith C. Chow, John G. Watson, George G. Rhoads,
and Paul J. Lioy Title:Chemical Mass Balance Source Apportionment of
Lead in House Dust Journal:Environ. Sci. Technol., 32 (1), 108 -114,
1998. Abstract: Chemical mass balance was used to apportion the major
proximate contributors of lead mass to house dust (HDPb) obtained from urban
Jersey City, NJ, homes of children at risk for lead exposure. Coarse (up to ~60
m) and PM10 (<10 m) particle size fractions of vacuum dust samples from 64
residences with lead-based paints were analyzed for Pb and 16 other elements.
Source profiles were developed to represent proximate source media contributors
to HDPb pre-1960 interior lead-based paints, indoor air, and a crustal source
profile that accounted for the contribution of yard soils and street dusts. On
average for both size fractions the exterior proximate sources, i.e., crustal
materials and deposited airborne particulates, were responsible for
approximately two-thirds of the HDPb mass; the interior lead-based paint sources
contributed the remaining third. Results indicate considerable variability in Pb
source contributors between homes, but little dif ference in the source
contributors to the two overlapping size fractions within homes. Effective
reduction of HDPb levels will require control of both exterior and interior
sources.
Author:Angle Carol;McIntire Matilda Title:Environmental lead and children: The Omaha study Journal:Journal of Toxicology and Environmental Health Volume 5, Issue 5 September 1979 , pages 855 - 870
Abstract:Blood lead (Pb B) was determined in 1232 samples from 831 children in Omaha and correlated with air lead (Pb A) concentrations of 0.02-1.69 μg/m3 from 1971 to 1977. A bivariate equation for ages 6-18 yr based on these data predicts on increase in Pb B of 1.4 μg/dl as Pb A increases from 1 to 2 μg/m3. Pb B increases 7 μg/dl as the mean values for soil and house dust Pb increase from 100 to 750 μg/g. Multiple regression analysis shows that the combined effects of air, soil, and house dust Pb account for 21% of the variance of Pb B, with a high intercorrelation of all 3 variables. Since the variance of repeat sampling in individuals accounted for 38% of the total variance of Pb B, approximately 40% is unexplained and requires measurement of Pb from dietary and other sources.
Reference Type: Journal Article Record
Number: 14 Author: Alonso, E.; Cambra, K.; Martinez,
T. Year: 2001 Title: Lead and cadmium exposure from
contaminated soil among residents of a farm area near an industrial
site Journal: Archives of Environmental Health.
56(3) Volume: 56(3) Pages: 278-82 Accession
Number: 11480506 Abstract: In this study, the authors determined
the degree of lead and cadmium exposure in a population that resided in an area
with contaminated soil. The extent of exposure from soil pollution was also
assessed. Lead and cadmium concentrations in blood of children and adults who
resided in the contaminated area were measured, and cadmium concentration in
urine of adults was also determined. An adult control group was recruited from a
nonpolluted area. The mean blood lead level in adults who resided in the
polluted area was 9.8 microg/dl, compared with a mean level of 6.8 microg/dl in
controls (p = .004). Urinary cadmium levels were well below the level associated
with onset of symptoms, but the differences between levels in residents of the
contaminated area (0.54 microg/gm creatinine) and levels in the controls (0.37
microg/gm creatinine) indicated that life-long cadmium exposure had been higher
among the residents of the contaminated area (p = .086). The mean blood lead
level and mean blood cadmium level in children were 5.2 microg/dl (maximum =
7.90 microg/dl) and 0.10 microg/l, respectively. Lead in soil accounted in large
part for the differences in blood lead levels in children; however, blood
cadmium levels were not associated with soil cadmium levels, but, rather, with
consumption of home-grown vegetables. Notes: Journal
Article
Reference Type: Journal Article Record
Number: 81 Author: Angle, C. R.; McIntire, M. S. Title:
Environmental lead and children: the Omaha study Journal: Journal of
Toxicology & Environmental Health. Volume: 5(5) Pages:
855-70. Accession Number: 583166 Abstract: Blood lead (Pb B)
was determined in 1232 samples from 831 children in Omaha and correlated with
air lead (Pb A) concentrations of 0.02-1.69 microgram/m3 from 1971 to 1977. A
bivariate equation for ages 6-18 yr based on these data predicts an increase in
Pb B of 1.4 microgram/dl as Pb A increases from 1 to 2 microgram/m3. Pb B
increases 7 microgram/dl as the mean values for soil and house dust Pb increase
from 100 to 750 microgram/g. Multiple regression analysis shows that the
combined effects of air, soil, and house dust Pb account for 21% of the variance
of Pb B, with a high intercorrelation of all 3 variables. Since the variance of
repeat sampling in individuals accounted for 38% of the total variance of Pb B,
approximately 40% is unexplained and requires measurement of Pb from dietary and
other sources. Notes: Journal Article
Reference Type: Journal Article Record Number:
58 Author: Aschengrau, A.; Beiser, A.; Bellinger, D.; Copenhafer, D.;
Weitzman, M. Title: The impact of soil lead abatement on urban
children's blood lead levels: phase II results from the Boston Lead-In-Soil
Demonstration Project Pages: 125-48, 1994 Nov. Accession
Number: 7982389 Abstract: The Boston Lead-In-Soil Demonstration
Project was a randomized environmental intervention study of the impact of urban
soil lead abatement on children's blood lead levels. Lead-contaminated soil
abatement was associated with a modest reduction in children's blood lead levels
in both phases of the project; however, the reduction in Phase II was somewhat
greater than that in Phase I. The combined results from both phases suggest that
a soil lead reduction of 2060 ppm is associated with a 2.25 to 2.70
micrograms/dl decline in blood lead levels. Low levels of soil recontamination 1
to 2 years following abatement indicate that the intervention is persistent, at
least over the short-term. Furthermore, the intervention appears to benefit most
children since no measurable differences in efficacy were observed for starting
blood and soil lead level, race, neighborhood, gender, and many other
characteristics. However, soil abatement did appear to be more beneficial to
children in the higher socioeconomic classes, with low baseline ferritin levels,
and who spent time away from home on a regular basis and lived in nonowner
occupied housing, and with adults who had lead-related hobbies and almost always
washed their hands before meals. Children who lived in apartments with
consistently elevated floor dust lead loading levels derived almost no benefit
from the soil abatement. It was not possible to separate the effects of the
variables that had a beneficial impact on efficacy because they were closely
correlated and the number of subjects was small. We recommend that further
research be conducted to identify subgroups of children to whom soil lead
abatement might be targeted. Notes: Environmental Research.
67(2) Clinical Trial Clinical Trial, Phase II Journal
Article Randomized Controlled Trial
Reference Type: Journal Article Record Number:
39 Author: Aschengrau, A.; Beiser, A.; Bellinger, D.; Copenhafer, D.;
Weitzman, M. Year: 1997 Title: Residential lead-based-paint
hazard remediation and soil lead abatement: their impact among children with
mildly elevated blood lead levels Journal: American Journal of Public
Health. Volume: 87(10) Pages: 1698-702. Accession
Number: 9357358 Abstract: OBJECTIVES: This prospective study
describes the impact of residential lead-based-paint hazard remediations on
children with mildly elevated blood lead levels. METHODS: Changes in blood lead
levels were observed following paint hazard remediation alone and in combination
with soil abatement. RESULTS: After adjustment for the confounding variables
paint hazard remediation alone was associated with a blood lead increase of 6.5
micrograms/dL (P = 0.5), and paint hazard remediation combined with soil
abatement was associated with an increase of 0.9 microgram/dL (P = 36).
CONCLUSIONS: Lead-based-paint hazard remediation as performed in this study, is
not an effective secondary prevention strategy among children with mildly
elevated blood lead levels. Notes: Journal
Article
Reference Type: Journal Article Record
Number: 53 Author: Bates, M.; Malcolm, M.; Wyatt, R.; Garrett, N.;
Galloway, Y.; Speir, T.; Read, D. Year: 1995 Title: Lead in
children from older housing areas in the Wellington region Journal:
New Zealand Medical Journal. Volume: 108(1009). Pages:
400-4. Accession Number: 7478332 Abstract: AIMS. To examine
blood lead levels in children, aged 12 to 23 months, living in old housing areas
of Wellington and Lower Hutt, and to investigate risk factors for high lead
levels. METHOD. Children were selected from Plunket Society rolls. Venous blood
samples were collected, and care givers were interviewed with a questionnaire.
Soil samples were taken from around the children's homes. Both soil and blood
samples were analysed for lead content. RESULTS. Blood samples and completed
questionnaires were obtained for 143 children. The geometric mean blood lead
level for all the children was 0.25 mumol/L (5.1 micrograms/dL) (95% confidence
interval [95% CI]: 0.22-0.28 mumol/L). Three children had blood lead levels that
exceeded the level for notification in New Zealand 1.45 mumol/L and a further 13
had blood lead levels exceeding 0.48 mumol/L. Children with elevated lead levels
were likely to live in a house greater than 50 years old where paint removal had
taken place in the last 2 years (risk ratio [RR] = 14.4, 95% CI: 2-107). Eating
dirt, particularly for children who usually played outside within 2 metres of
the house, was also a risk factor for elevated blood lead levels. Soil lead
levels generally increased with the age of the house and were weakly correlated
with blood lead levels (r = 0.32). CONCLUSION. Paint removal in old houses is a
major risk factor for elevated blood lead levels. However, the number of study
children living in houses less than 50 years old was limited. Because of this
and possible participant selection bias, the results of this study require
confirmation in a separate population-based study. Information about the
specific paint removal procedures that cause high lead levels is also
needed.
<Author: Michael E. Beard and S.D. Allen. 1995.
. Title:Lead in Paint, Soil, and Dust: Health Risks, Exposure Studies, Control Measures, Measurement Methods, and Quality Assurance. ASTM STP 1226. Philadelphia: American Society for Testing and Materials.
Author: Binns HJ, Gray KA, Chen T, Finster ME, Peneff N, Schaefer P,
Ovsey V, Fernandes J, Brown M, Dunlap B. Title:Evaluation of landscape
coverings to reduce soil lead hazards in urban residential yards: The Safer
Yards Project. Abstract:This study was designed primarily to evaluate
the effectiveness of landscape coverings to reduce the potential for exposure to
lead-contaminated soil in an urban neighborhood. Residential properties were
randomized in to three groups: application of ground coverings/barriers plus
placement of a raised garden bed (RB), application of ground coverings/barriers
only (no raised bed, NRB), and control. Outcomes evaluated soil lead
concentration (employing a weighting method to assess acute hazard soil lead
[areas not fully covered] and potential hazard soil lead [all soil surfaces
regardless of covering status]), density of landscape coverings (6 = heavy, >
90% covered; 1 = bare, < 10% covered), lead tracked onto carpeted entryway
floor mats, and entryway floor dust lead loadings. Over 1 year, the intervention
groups had significantly reduced acute hazard soil lead concentration (median
change: RB, -478 ppm; NRB, -698 ppm; control, +52 ppm; Kruskal-Wallis, P =
0.02), enhanced landscape coverings (mean change in score: RB, +0.6; NRB, +1.5;
control, -0.6; ANOVA, P < 0.001), and a 50% decrease in lead tracked onto the
floor mats. The potential hazard soil lead concentration and the entryway floor
dust lead loading did not change significantly. Techniques evaluated by this
study are feasible for use by property owners but will require continued
maintenance. The long-term sustainability of the method needs further
examination. SourceEnviron Res. 2004 Oct;96(2):127-38.
Reference Type: Journal Article Author: Boreland F,
Lyle DM. Year: 2006 Title: Lead dust in Broken Hill homes:
effect of remediation on indoor lead levels. Journal: Environ
Res. Volume: 100(2) Pages: 276-83 Abstract:This
study was undertaken to determine whether home remediation effectively reduced
indoor lead levels in Broken Hill, a long-established silver-lead-zinc mining
town in outback Australia. A before-after study of the effect of home
remediation on indoor lead levels was embedded into a randomized controlled
trial of the effectiveness of remediation for reducing elevated blood lead
levels in young children. Moist towelettes were used to measure lead loading
(microg/m2) on internal windowsills and internal and entry floors of 98 homes;
samples were collected before, immediately after, and 2, 4, 6, 8, and 10 months
after remediation. Data were log(10) transformed for the analysis. Remediation
reduced average indoor lead levels by approximately 50%, and lead levels
remained low for the duration of the follow-up period (10 months). The greatest
gains were made in homes with the highest initial lead levels; homes with low
preremediation lead levels showed little or no benefit. Before remediation,
homes located in areas with high soil lead levels or with "poor" dust proofing
had higher lead levels than those in areas with lower soil lead levels or with
"medium" or "good" dust proofing; these relative differences remained after
remediation. There was no evidence that lead loading was reduced by an increased
opportunity to become aware of lead issues. We conclude that remediation is an
effective strategy for reducing the lead exposure of children living in homes
with high indoor lead levels.
Author:Campbell C, Schwarz DF,
Rich D, Dockery DW. 2003. Effect of a follow-up professional home cleaning on
serial dust and blood lead levels of urban children. Arch Environ Health.
Dec;58(12):771-80. Abstract:Children residing in Philadelphia,
Pennsylvania, who were enrolled in a clinical trial of oral chelation therapy
(n=73) were studied to determine the effects of a follow-up professional lead
dust cleaning of their homes 18 mo after an initial cleaning and commencement of
therapy. Home dust lead levels were determined from dust-wipe specimens
collected from the kitchen and playroom floors, and from a playroom windowsill,
prior to, immediately following, and 3 and 6 mo after the second cleaning.
Children's blood lead levels were assessed at 3-mo intervals before and after
the follow-up cleaning. Professional cleaning produced immediate decreases in
dust lead levels; however, dust lead re-accumulated to precleaning levels within
3-6 mo. Frequent, repeated cleanings may be required if blood lead or dust lead
levels are to be reduced and sustained at low levels in urban homes.
Author:Caravanos, Jack, Weiss, Arlene and Jaeger, Rudolph. 2005.
An exterior and interior leaded dust deposition survey in New York City: Results
of a 2-year study. Environmental Research. Abstract: Environmental
concentrations of leaded dust were monitored by weekly sample collection of
interior and exterior settled dust that had accumulated due to atmospheric
deposition. The weekly deposition amounts were measured and the cumulative rates
of lead in dust that deposited on a weekly basis over 2 year's time were
determined. The sampling analysis revealed that the median values of leaded dust
for the interior plate (adjacent to the open window), unsheltered exterior
plate, and the sheltered exterior plate were 4.8, 14.2, and 32.3 g/feet2/week,
respectively. The data supports the existence of a continuous source of
deposited leaded dust in interior and exterior locations within New York City.
Additional data from a control plate (interior plate with the window closed)
demonstrate that the source of the interior lead deposition was from exterior
(environmental) sources. Because of the ubiquitous nature of lead in our
environment and the toxic threat of lead to the cognitive health of children,
this data provides a framework for the understanding of environmental exposure
to lead and its potential for continuing accumulation within an urban
environment.
Author:Caravanos, Jack, Blaise, Marc. J., Weiss,
Arlene and Jaeger, Rudolph. 2005. A survey of spatially distributed exterior
dust lead loadings in New York City Abstract: This work documents ambient
lead dust deposition values (lead loading) for the boroughs of New York City in
2003-2004. Currently, no regulatory standards exist for exterior concentrations
of lead in settled dust. This is in contrast to the clearance and risk
assessment standards that exist for interior residential dust. The reported
potential for neurobehavioral toxicity and adverse cognitive development in
children due to lead exposure prompts public health concerns about undocumented
lead sources. Such sources may include settled dust of outdoor origin. Dust
sampling throughout the five boroughs of NYC was done from the top horizontal
portion of pedestrian traffic control signals (PTCS) at selected street
intersections along main thoroughfares. The data (n=214 samples) show that lead
in dust varies within each borough with Brooklyn having the highest median
concentration (730 g/ft2), followed in descending order by Staten Island (452
g/ft2), the Bronx (382 g/ft2), Queens (198 g/ft2) and finally, Manhattan (175
g/ft2). When compared to the HUD/EPA indoor lead in dust standard of 40 g/ft2,
our data show that this value is exceeded in 86% of the samples taken. An effort
was made to determine the source of the lead in the dust atop of the PTCS. The
lead in the dust and the yellow signage paint (which contains lead) were
compared using isotopic ratio analysis. Results showed that the lead-based paint
chip samples from intact signage did not isotopically match the dust wipe
samples taken from the same surface. We know that exterior dust containing lead
contributes to interior dust lead loading. Therefore, settled leaded dust in the
outdoor environment poses a risk for lead exposure to children living in urban
areas, namely, areas with elevated childhood blood lead levels and background
lead dust levels from a variety of unidentified sources.
Author:Leticia Carrizalesa, Israel Razoa, Jess I.
Tllez-Hernndeza, Roco Torres-Nerioa, Arturo Torresa, Lilia E. Batresa,
Ana-Cristina Cubillasb and Fernando Daz-Barrigaa, Title:Exposure to
arsenic and lead of children living near a copper-smelter in San Luis Potosi,
Mexico: Importance of soil contamination for exposure of children
Abstract:The objective of this study was to assess the levels of soil
contamination and child exposure in areas next to a primary smelter
(arsenic copper metallurgical) located in the community of Morales in San Luis
Potosi, Mexico. In Morales, 90% of the soil samples studied in this work were
above 400 mg/kg of lead, and above 100 mg/kg of arsenic, which are guidelines
recommended by the United States Environmental Protection Agency (EPA).
Bioaccessibility of these metals was studied in vitro in 10 soil samples; the
median values of bioaccessibility obtained in these samples were 46.5% and 32.5%
for arsenic and lead. Since the concentrations of arsenic and lead in soil were
above normal values, and taking into account the bioaccessibility results,
exposure to these metals was evaluated in children. Regarding lead, children
aged 3-6 years had the highest mean blood lead levels; furthermore, 90% of them
had concentrations above 10 μg/dl (CDC's action level). Total urinary arsenic
was higher in children aged 8-9 yr; however, the percentage of children with
concentrations above 50 μg/g creatinine (CDC's action level) or 100 μg/g
creatinine (World Health Organization [WHO] action level) was similar among
different age groups. Using the EPAs integrated exposure uptake biokinetic model
for lead in children (IEUBK), we estimated that 87% of the total lead in blood
is obtained from the soil/dust pathway. The exposure dose to arsenic, estimated
for the children living in Morales using Monte Carlo analysis and the arsenic
concentrations found in soil, was above the EPA's reference dose. With all these
results, it is evident that studies are needed in order to identify adverse
health effects in children living in Morales; nevertheless, it is more important
to develop a risk reduction program as soon as
possible. Notes:Environmental Research Volume 101, Issue 1 , May 2006,
Pages 1-10
Reference Type: Journal Article Record
Number: 79 Author: Charney, E.; Sayre, J.; Coulter,
M. Title: Increased lead absorption in inner city children: where does
the lead come from? Pages: 226-31, 1980 Feb. Accession
Number: 7354967 Abstract: Pica for lead-containing paint has been
questioned as the principal mechanism for the widespread moderately elevated
blood lead levels (30 to 80 microgram/100 ml) in inner city children. This study
explored the hypothesis that lead-contaminated household dust is a major source
of lead for these children; hand contamination and repetitive mouthing is the
proposed mechanism of ingestion. Forty-nine inner city children with blood lead
40 to 70 microgram/100 ml were matched with 50 children with blood lead less
than or equal to 29 microgram/100 ml from the same inner city environment. House
dust lead and lead on hands were found in significantly greater quantity among
experimental subjects. Other factors differed between groups; lead content of
peeling paint, soil lead, and pica affected more experimental than control
children, but did not account for more than 50% of experimental cases. The cause
of moderate blood lead elevation is multifactoral: no single source accounted
for all children with elevated levels. However, lead contamination of house dust
and hands appears to be a major factor in this condition. Notes:
Pediatrics. 65(2) Journal Article
Reference Type: Journal
Article Record Number: 42 Author: Cikrt, M.; Smerhovsky, Z.;
Blaha, K.; Nerudova, J.; Sediva, V.; Fornuskova, H.; Knotkova, J.; Roth, Z.;
Kodl, M.; Fitzgerald, E. Title: Biological monitoring of child lead
exposure in the Czech Republic Pages: 406-11, 1997
Apr. Accession Number: 9189705 Abstract: The area around the
Pribram lead smelter has been recognized to be heavily contaminated by lead
(Pb). In the early 1970s, several episodes of livestock lead intoxication were
reported in this area; thereafter, several epidemiological and ecological
studies focused on exposure of children. In contrast to earlier studies, the
recent investigation (1992-1994) revealed significantly lower exposure to lead.
From 1986-1990, recorded average blood lead levels were about 37.2 micrograms
lead (Pb)/100 ml in an elementary school population living in a neighborhood
close to the smelter (within 3 km of the plant). The present study, however, has
found mean blood lead levels of 11.35 micrograms/100 ml (95% CI = 9.32; 13.82)
among a comparable group of children. In addition to blood lead, tooth lead was
used to assess exposure among children. Statistically significant differences (p
< 0.05) were observed between the geometric mean tooth lead level of 6.44
micrograms Pb/g (n = 13; 95% CI = 3.95; 10.50) in the most contaminated zone and
1.43 micrograms Pb/g (n = 35; 95% CI = 1.11; 1.84) in zones farther away from
the point source. Both biomarkers, blood and tooth lead levels, reflect a
similar pattern of lead exposure in children. This study has attempted a
quantitative assessment of risk factors associated with elevated lead exposure
in the Czech Republic. Content of lead in soil, residential distance from the
smelter, consumption of locally grown vegetables or fruits, drinking water from
local wells, the mother's educational level, cigarette consumption among family
members, and the number of children in the family were factors positively
related (p < 0.05) to blood lead levels. The resulting blood lead level was
found to be inversely proportional to the child's age. Notes:
Environmental Health Perspectives. 105(4) Journal
Article
Author:Heather F. Clark, Daniel J. Brabander and
Rachel M. Erdil Title:Sources, Sinks, and Exposure Pathways of Lead
in Urban Garden Soil Abstract:The chemistry of Pb in urban soil must
be understood in order to limit human exposure to Pb in soil and produce and to
implement remediation schemes. In inner-city gardens where Pb contamination is
prevalent and financial resources are limited, it is critical to identify the
variables that control Pb bioavailability. Field-portable X-ray fluorescence was
used to measure Pb in 103 urban gardens in Roxbury and Dorchester, MA, and 88%
were found to contain Pb above the USEPA reportable limit of 400 mg/kg.
Phosphorus, iron, loss on ignition, and pH data were collected, Pb-bearing
phases were identified by X-ray diffraction, and Pb isotopes were measured using
inductively coupled plasma mass spectrometry. Four test crops were grown both in
situ and in Roxbury soil in a greenhouse, and plant tissue was analyzed for Pb
uptake by polarized energy-dispersive X-ray fluorescence. Variation at the
neighborhood scale in soil mineralogical and chemical characteristics suggests
that the bioavailable fraction of Pb in gardens is site specific. Based on Pb
isotope analysis, two historical Pb sources appear to dominate the inventory of
Pb in Roxbury gardens: leaded gasoline (207 Pb/206 Pb = 0.827) and Pb-based
paint (207Pb/206 Pb = 0.867). Nearly 70% of the samples analyzed can be
isotopically described by mixing these two end members, with Pb-based paint
contributing 40 to 80% of the mass balance. A simplified urban human exposure
model suggests that the consumption of produce from urban gardens is equivalent
to approximately 10 to 25% of children's daily exposure from tap water.
Furthermore, analysis of over 60 samples of plant tissue from the four test
species suggests that in these urban gardens unamended phytoremediation is an
inadequate tool for decreasing soil Pb. Notes:J Environ Qual
35:2066-2074 (2006), DOI: 10.2134/jeq2005.0464
Author:Clark S,
Menrath W, Chen M, Succop P, Bornschein R, Galke W, Wilson
J. Abstract:To aid in understanding the contribution of exterior
dust/soil lead to postintervention interior dust lead, a subset of housing from
the HUD Lead-Based Paint Hazard Control Grant Program Evaluation was selected
for study. Housing from 12 state and local governments was included. Exterior
entry and street dust samples were obtained by a vacuum method, and soil samples
were building perimeter core composites. Interior dust wipe lead data
(microg/ft(2)) and paint lead data (mg/cm(2)) were also available for each of
the dwelling units and included in the modeling. Results from 541 dwelling units
revealed a wide range of exterior dust and soil lead levels, within and between
grantees. Minimum and maximum geometric mean lead levels, by grantee, were 126
and 14400 microg/ft(2) for exterior entry dust; 325 and 4610 microg/ft(2) for
street dust; and, for soil concentration, 383 and 2640 ppm. Geometric mean
exterior entry dust lead concentration (1641 ppm) was almost four times as high
as street dust lead concentration (431 ppm), suggesting that lead dust near
housing was often a source of street dust lead. Geometric mean exterior entry
dust lead loading was more than four times as high as window trough dust lead
loading and more than an order of magnitude higher than interior entry dust lead
loading. Statistical modeling revealed pathways from exterior entry dust lead
loading to loadings on interior entryway floors, other interior floors, and
windowsills. Paint lead was found to influence exterior entry dust lead. Results
of this study show that housing where soil lead hazard control activities had
been performed had lower postintervention exterior entry, interior entry floor,
windowsills, and other floor dust loading levels. Soil was not present for
almost half the buildings. Statistical analysis revealed that exterior strategy
influenced soil lead concentration, and soil lead concentration influenced
street dust lead loading. This study represents one of the few where an impact
of soil treatments on dust lead levels within the housing has been documented
and may represent the first where an impact on exterior entry dust lead has been
found. The inclusion of measures to mitigate the role of exterior sources in
lead hazard control programs needs consideration. Notes:J Occup
Environ Hyg. 2004 May;1(5):273-82.
Author:Culbard E, Thornton I,
Watt J, Wheatley, M, Moorcroft S, Thompson M. 1988. Metal contamination in
British urban dusts and soils. J Environ Qual 17:226-234. Abstract:
Reference Type: Journal Article Record Number:
55 Author: Devey, P.; Jingda, L. Title: Soil lead levels in
parks and playgrounds: an environmental risk assessment in
Newcastle Pages: 189-92, 1995 Apr. Accession Number:
7786947 Abstract: In June 1993 the National Health and Medical
Research Council set a national goal for blood lead of below 10 micrograms/dl.
There is a need to know if the lead contamination of the urban environment is so
high as to put community health at risk. Decisions, including whether soil
should be removed and replaced, will have to be made. During the second half of
1993, an environmental assessment of lead contamination of soil within the City
of Newcastle was conducted. Samples, 108 from surface soil and 10 from
subsurface soil, were taken from public parks and playgrounds in the city area
and analysed for lead content. The proportion within and the proportion above
the guidelines for soil contamination were reported. Lead concentrations ranged
from 25 to 2400 parts per million (ppm); 21 per cent of samples had
concentrations higher than the 300 ppm action level, and the geometric mean was
134 ppm. Both the range and the average lead levels were typically no more than,
or were even less than, soil lead levels documented for other cities in
Australia, the United States and United Kingdom. Although each sampling site was
noted, it was not our intention to focus in on individual sites. Indeed, to draw
health-risk implications from any one result may be misleading and inaccurate.
The results indicated moderate lead contamination of soil that could be
controlled by regular top-dressing of soils, the use of bark chip on playground
surfaces and by government initiatives aimed at lowering lead levels in
petrol. Notes: Australian Journal of Public Health. 19(2) Journal
Article
Author: Dixon SL, McLaine P, Kawecki C, Maxfield R, Duran S, Hynes P,
Plant T. Title:The effectiveness of low-cost soil treatments to reduce
soil and dust lead hazards: The Boston lead safe yards low cost lead in soil
treatment, demonstration and evaluation. Abstract:The Boston lead
safe yards low cost lead in soil treatment, demonstration, and evaluation was
developed to explore the viability and effectiveness of low-cost soil
interventions to reduce exposure to soil lead hazards. Buildings that had been
abated for lead to Massachusetts's deleading standards in the previous 5yrs and
met other program requirements were recruited for the evaluation. Following
individual property assessments, yards were treated with application of ground
coverings and ground barriers in 2000-2001 and followed up at 1yr. The treatment
cost ranged from $1095 to $5643 with an average of $2798. Soil lead levels at
the building dripline, measured with a field-portable X-ray fluorescence
analyzer (Niton Model 702 Spectrum Analyzer), dropped from 2021PPM at baseline
to 206PPM at 1-yr follow-up. Most of the barrier treatments continued to block
access to the lead-contaminated soil at 1yr. At the follow-up, few properties
with grass treatment had areas that were completely bare, but 28% had more than
a small amount of treated areas bare. Treatments were effective in reducing
entryway dust lead in the rear of the building if the residents reported they
had maintained the yard treatments. Each additional yard work activity reported
was predicted to lower 1-yr floor dust lead loading at the rear common/main and
dwelling unit entries by about 20%. Each additional 100ft(2) of yard treated was
predicted to lower 1-yr floor dust loading at the rear dwelling unit entry by
19%. Treatments did not show a dust lead effect at 1yr in the front entryway of
the building, but the investigators believe that this may be due to the effect
of resident cleaning overshadowing the treatment effect. Notes:
Environ Res. 2006 Feb 23; [Epub ahead of print]
Author:Duggan MJ.
Title:Contribution of lead in dust to children's blood lead
Abstract:The importance of urban dust as a source of lead for young children is still disputed. Although blood-lead data from various population surveys usually show a peak concentration in early childhood, there is evidence that such a peak is small or absent altogether in children without much access to the general environment. An examination of those studies where groups of people in regions of low and high lead contamination have been compared shows that the child/adult blood-lead ratio is almost always enhanced in the more exposed groups. This implies a route of lead uptake which is important for children but less so for adults, and it is likely that this route is the dust-hand-mouth one. There are sufficient data to suggest a quantitative relationship between raised levels of blood lead and lead in dust. There is a strong case for a lead-in-dust standard but some will probably remain unpersuaded unless or until there are reliable data for blood lead and environmental lead involving matched groups of young people from urban and rural areas.
Source:Environ Health Perspect. 1983 Apr;50:371-81.
Reference Type: Journal Article Record Number:
56 Author: Elhelu, M. A.; Caldwell, D. T.; Hirpassa, W.
D. Title: Lead in inner-city soil and its possible contribution to
children's blood lead Pages: 165-9, 1995 Mar-Apr. Accession
Number: 7786053 Abstract: This study was designed to assess
distribution and sources of lead in inner-city soils in Washington, D.C.
Duplicate soil samples were collected randomly from 239 unpaved front yards of
homes in Washington, D.C. Soil samples were collected 1 m from the houses. Lead
concentration in soil was determined by flame atomic absorption
spectrophotometry. Presence of lead detected in soil was correlated and traced
to the anticipated source of origin. A significantly high concentration of lead
was present in inner-city soils. Areas of the city in which the highest lead
concentrations were found (Wards 1, 4, 5, 6, 7, 8) were determined to contain a
large number of residents who had attained lower education levels than most
residents in the remaining wards. It was concluded that lead concentration in
inner-city soil plays a significant role in the incidence of lead poisoning in
children in the District of Columbia and that paint is the main source of soil
lead. Demographic characteristics of the residents appeared to enhance the
distribution of lead poisoning. Notes: Archives of Environmental
Health. 50(2) Journal Article
Reference Type: Journal
Article Record Number: 73 Author: Elwood, P.
C. Title: The sources of lead in blood: a critical
review Pages: 1-23, 1986 Jun. Accession Number:
3523752 Notes: Review Science of the Total Environment.
52(1-2) Journal Article
Reference Type: Journal
Article Record Number: 63 Author: Fett, M. J.; Mira, M.;
Smith, J.; Alperstein, G.; Causer, J.; Brokenshire, T.; Gulson, B.; Cannata,
S. Title: Community prevalence survey of children's blood lead levels
and environmental lead contamination in inner Sydney.[see
comment] Pages: 441-5, 1992 Oct 5. Accession Number:
1406391 Abstract: OBJECTIVE: To determine the distribution of blood
lead levels in preschool children in inner Sydney and identify possible sources
of environmental lead. DESIGN: Cross sectional community based prevalence survey
of children and the houses in which they live, and a survey of volunteer
children. SETTING: Mort Bay and Summer Hill, residential localities in inner
Sydney. PARTICIPANTS: Ninety-five children aged 9-48 months able to be
identified in a defined geographic area and 63 children aged 9-48 months
volunteered by their parents. OUTCOME MEASURES: Concentrations of lead in venous
blood of all children and in samples from the home environment of Mort Bay
children. RESULTS: Four of the children (2.5%) had blood lead levels > or =
1.21 mumol/L (25 micrograms/dL, the current Australian threshold of concern), 27
(17.1%) had levels > or = 0.72 mumol/L (15 micrograms/dL, the new US
threshold for individual intervention) and 80 (50.6%) had levels > or = 0.48
mumol/L (10 micrograms/dL, the new US threshold for community intervention).
Blood lead concentrations were significantly correlated with concentrations of
lead in "sink" soil (r = 0.555, P = 0.026), play area soil (r = 0.492, P =
0.016) and dust from vacuum cleaners (r = 0.428, P = 0.05), and with age of
child (r = -0.182, P = 0.023). The presence of the child during house renovation
was a strong predictor of having a blood lead level above 0.72 mumol/L (15
micrograms/dL) (odds ratio, 4.6; 95% confidence interval, 1.8-11.7, P = 0.001).
CONCLUSIONS: Lead in soil and in household dust in older areas of Sydney is
likely to represent a significant health hazard to young children. Many
thousands of children may be affected in Sydney and other Australian cities.
There is an urgent need for expanded prevalence surveys, public education and
the development of strategies for the abatement of lead in urban
environments. Notes: Medical Journal of Australia. 157(7) Journal
Article
Author: Filippelli, Gabriel M., Laidlaw, Mark A.S, Title: The Elephant in the Playground: confronting lead-contaminated soils as an important source of lead burdens to urban populations Reference: Perspectives in Biology and Medicine. volume 53, number 1 (winter 2010):31-45. abstract: Although significant headway has been made over the past 50 years
in understanding and reducing the sources and health risks of lead, the incidence of
lead poisoning remains shockingly high in urban regions of the United States.At particular
risk are poor people who inhabit the polluted centers of our older cities without
the benefits of adequate nutrition, education, and access to health care.To provide
a future with fewer environmental and health burdens related to lead,we need to consider
the multiple pathways of lead exposure in children, including their continued
contact with dust derived from inner-city soils.Recent research into the causes of seasonal
variations in blood-lead levels among children has confirmed the importance of
soil in lead exposure. Capping lead-contaminated soil with lead-free soil or soil
amendment appears to be a simple and cost-effective way to reduce the lead load for
urban youth.
Author Filippelli, Gabriel M., Laidlaw, Mark A.S.,
Latimer, Jennifer C., Raftis, Robyn Urban Lead Poisoning and Medical Geology: An
Unfinished Story GSA Today 2005 15: 4-11 ABSTRACT: The intersection
between geological sciences and human health, termed medical geology, is gaining
significant interest as we understand more completely coupled biogeochemical
systems. An example of a medical geology problem largely considered solved is
that of lead (Pb) poisoning. With aggressive removal of the major sources of Pb
to the environment, including Pb-based paint, leaded gasoline, and lead pipes
and solder, the number of children in the United States affected by Pb poisoning
has been reduced by 80%, down to a current level of 2.2%. In contrast to this
national average, however, about 15% of urban children exhibit blood Pb levels
above what has been deemed safe (10 ug per deciliter); most of these are
children of low socioeconomic-status minority groups. We have analyzed the
spatial relationship between Pb toxicity and metropolitan roadways in
Indianapolis and conclude that Pb contamination in soils adjacent to roadways,
the cumulative residue from the combustion of leaded gasoline, is being
remobilized. Developing strategies to remove roadway Pb at the source is a
matter of public health and social justice, and constitutes perhaps the final
chapter in this particular story of medical geology.
Reference Type: Journal Article Record Number:
60 Author: Gagne, D. Title: Blood lead levels in Noranda
children following removal of smelter-contaminated yard soil Pages:
163-6, 1994 May-Jun. Accession Number: 7922959 Abstract: In
1979, children two to five years of age living in Rouyn-Noranda, QC, in an urban
district located within 1 km from a copper smelter had mean (geometric) blood
lead levels (BLL) of 21 micrograms/dL. Afterwards, stack emissions were lowered.
In 1989, mean (geom.) BLL were reduced to 11 micrograms/dL; 50% of the district
children had BLL less than 10 micrograms/dL. In 1990-91, a $3 million top soil
removal operation took place; residential lots having more than 500 ppm soil
lead were decontaminated. In 1991, BLL were reduced to 7 micrograms/dL; 75% of
the children had less than 10 micrograms/dL. Geographic analysis of the 1991
results showed that children with the highest BLL lived nearest to the smelter,
where atmospheric dustfall to the ground reached 36 mg/m2/month. Follow-up
pediatric blood lead campaigns are planned in 1993 and 1995, to evaluate the
effects of an ongoing program for further reduction of atmospheric smelter
emissions. Notes: Canadian Journal of Public Health. Revue Canadienne
de Sante Publique. 85(3) Journal Article
Reference Type: Journal Article Record Number:
26 Author: Gao, W.; Li, Z.; Wang, Z.; Wang, N.; Zhao, X.; Chen,
Y. Title: [Effects of environmental lead exposure in kindergartens on
children's blood lead level] Pages: 272-4, 1999 Sep. Accession
Number: 11864489 Abstract: OBJECTIVE: To determine if
kindergartens' environmental status can influence children's lead exposure.
METHODS: Environmental specimens, such as floor dust, peeled-off paint chip,
soil and drinking water, as well as children's hand dust and blood samples, were
collected and measured for their lead levels in 19 kindergartens, to analyze the
relationship between children's blood lead levels and their environmental lead
exposure. RESULTS: Geometric means of lead concentrations in indoor floor dust,
peeled-off paint chip, dust fallout, outdoor floor dust, soil and drinking water
were 86.5 microg/m(2), 235.5 microg/g, 445.9 microg/g, 172.4 microg/m(2), 70.1
microg/g and 12.5 microg/L, respectively. Lead level on children's hands
averaged 3.4 microg at both hands. Blood lead levels in children correlated
positively with the lead concentrations of outdoor floor dust and their hand
dust, with correlation coefficients of 0.5186 and 0.2206, respectively. Multiple
regression analysis showed that hand dust lead level in children entered the
regression model with a largest standardized partial regression coefficient of
0.3842 and a coefficient of determination of 0.673 for the full equation with F
= 6.52 and P < 0.01. CONCLUSION: Status of environmental health in
kindergartens plays an important role in children's lead exposure. It is
necessary to offer health education for children and make them wash their hands
often and overcome unhealthy behavior of sucking their fingers. Notes:
Chinese Chung-Hua Yu Fang i Hsueh Tsa Chih [Chinese Journal of Preventive
Medicine]. 33(5) Journal Article
Reference Type: Journal
Article Record Number: 8 Author: Gonzalez, E. J.; Pham, P.
G.; Ericson, J. E.; Baker, D. B. Title: Tijuana childhood lead risk
assessment revisited: validating a GIS model with environmental
data Pages: 559-65, 2002 Apr. Accession Number:
12071505 Abstract: The objective of this research was to determine the
spatial distributions of childhood lead poisoning and soil lead contamination in
urban Tijuana. The Bocco-Sanchez model of point-source emissions was evaluated
in terms of validity and reliability. We compared the model's predicted
vulnerable populations with observed cases of childhood lead poisoning in
Tijuana, identified fixed point sources in the field, and analyzed 76 soil
samples from 14 sites. The soil lead results were compared to the blood lead
analyses performed on Tijuana children whose blood lead levels were > or =10
microg/dL, who reported that they did not use lead-glazed ceramics for cooking
or storing food (n = 63). Using GIS, predicted vs observed risk areas were
assessed by examining spatial patterns, including the distribution of cases per
designated risk area. Chi-square analysis of expected vs observed values did not
differ significantly at the p = 0.02 level, showing that the model was
strikingly accurate in predicting the distribution of subjects with elevated
blood lead. Results reveal that while point sources are significant, other
sources of lead exposure are also important. The relative public health risk
from exposure to lead in an urban setting may be assessed by distinguishing
among sources of exposure and associating concentrations to blood lead levels.
The results represent an iterative approach in environmental health research by
linking environmental and human biomarker lead concentrations and using these
results to validate an environmental model of risk to lead
exposure. Notes: Environmental Management. 29(4) Journal
Article Validation Studies
Title: Sources of lead in soil
and dust and the use of dust fallout as a sampling medium Author:B. L.
Gulson, J. J. Davis, K. J. Mizon, M. J. Korsch and J. Bawden-Smith
Abstract: Pilot investigations using stable lead isotope and scanning
electron microscopic analyses have been undertaken in different environments
ranging from mining and smelting to urban in order to better understand the
source of, and relationships between, soil and house dust. House dust is
characterised by vacuum cleaner dust and/or surface wipes and compared with
long-term dust (dust fall) accumulations over a > 3-month interval or with
airborne particulates. Finer grain sizes of soils have lead concentrations from
2 to 9 times those measured in the bulk fractions. In Broken Hill isotopic
ratios show that the major source of lead in soils is from the orebody, with
rare examples containing lead from paint sources. In inner Sydney, soil lead
values vary from 37 to 2660 ppm Pb in bulk samples and up to 3130 ppm in the
finer fractions. The lead may be from diverse sources such as gasoline or paint.
Finer fractions of vacuum cleaner dust from both Broken Hill and Sydney may
contain up to three times the amount of lead measured in the bulk samples. In
Broken Hill, the percentages by weight of total lead in the −250-μm fraction
range from 11 to 51%. Bulk vacuum cleaner dusts from Broken Hill contain up to
4490 ppm Pb. Bulk vacuum cleaner dusts from inner Sydney contain up to 2950 ppm
Pb. Isotopic variations in fractions of vacuum cleaner dust containing > 1000
ppm Pb from inner Sydney indicate that the lead in dust has come from different
sources and such differences lessen the usefulness of analyses of bulk vacuum
cleaner dust. Our results reinforce the importance of analysing the finer
fraction of soil and house dust, especially those in the −150-μm (or even
−100-μm) fraction for soils and the −100-μm fraction for vacuum cleaner dust.
Dust-fall accumulations have many advantages over more conventional methods for
estimating lead in house dust, such as vacuum cleaner dust or surface wipes.
These advantages include: low cost; no power source required; can be set up by a
technician; minimal inconvenience to householder (i.e., no power required, no
noise, out of the way, a few minutes to set up and collect); integrates lead
flux over a specific period; usually unbiased (in contrast to vacuuming or wipes
where the householder may clean prior to a sampling visit); easy to control by
placement of other dishes in the same house. For Broken Hill, a strong
correlation (r = 0.95) was obtained between the isotopic composition of lead in
blood and dust-fall accumulation. Abstract: Science of The Total
Environment Volume 166, Issues 1-3 , 21 April 1995, Pages 245-262
Author:Harris AR, Davidson CI.2005. The role of resuspended
soil in lead flows in the California South Coast Air Basin. Environ Sci Technol.
2005 Oct 1;39(19):7410-5. Abstract: The inputs and outputs of airborne
lead in the South Coast Air Basin of California (SOCAB) are quantified according
to standard mass balance calculations. Results for 2001 show that approximately
49,000 kg of lead exitthe Basin each year, but traditional sources contribute
only about 6500 kg of lead each year. We resolve this discrepancy through a
simple computer model that quantifies the resuspension of lead-containing
particles. Our results suggest that these lead particles were deposited during
the years of leaded gasoline use and that resuspension is responsible for
generating an additional 54,000 kg of airborne lead each year. This agrees
roughly with estimated outputs. Thus, we conclude that resuspension, although an
insignificant source of airborne lead during the era of leaded fuel, became a
principal source in the SOCAB as lead emissions from vehicles declined. The
results of the resuspension model further suggest that soil lead levels will
remain elevated for many decades, in which case resuspension will remain a major
source well into the future.
Reference Type: Journal
Article Record Number: 64 Author: Hertzman, C.; Ward, H.;
Ames, N.; Kelly, S.; Yates, C. Title: Childhood lead exposure in Trail
revisited Pages: 385-91, 1991 Nov-Dec. Accession Number:
1790501 Abstract: We sought to identify modifiable determinants of
elevated blood lead levels in preschool children; to compare the current
situation with past information; to determine historical trends in environmental
lead contamination in Trail; and to find a basis for identifying appropriate
precautions and protection against future lead exposure. In Phase 1, blood
samples were drawn from all children aged 2 to 5. In Phase 2, children in the
highest and lowest quartile of blood leads were surveyed by questionnaire.
Environmental samples of drinking water, paint, housedust, soil and vegetables
were taken from their residences, and soil samples were collected from nearby
parks. The average blood lead level was 13.8 micrograms/dl, range 4 to 30
micrograms/dl. This is approximately 40% lower than in 1975, when a previous
survey was done, but is high compared to other places in Canada. The study of
environmental determinants of lead revealed that soil lead levels and,
secondarily, housedust lead levels are the principal determinants of high blood
lead. Children with high blood leads also tended to concentrate in
neighbourhoods near the lead-zinc smelter. Notes: Canadian Journal of
Public Health. Revue Canadienne de Sante Publique. 82(6) Journal
Article
b>Reference Type: Journal Article Author:
Janneke Hogervorst, Michelle Plusquin, Jaco Vangronsveld, Tim Nawrot, Ann
Cuypers, Etienne Van Heck, Harry A. Roels, Robert Carleer and Jan A.
StaessenBR> Title:House dust as possible route of environmental
exposure to cadmium and lead in the adult general population Abstract:
Contaminated soil particles and food are established routes of exposure. We
investigated the relations between biomarkers of exposure to cadmium and lead,
and the metal loading rates in house dust in the adult residents of an area with
a soil cadmium concentration of 3 mg/kg (n=268) and a reference area (n=205). We
determined the metal concentrations in house dust allowed to settle for 3 months
in Petri dishes placed in the participants bedrooms. The continuously
distributed vegetable index was the first principal component derived from the
metal concentrations in six different vegetables. The biomarkers of exposure
(blood cadmium 9.2 vs. 6.2 nmol/L; 24-h urinary cadmium 10.5 vs. 7.0 nmol; blood
lead 0.31 vs. 0.24 μmol/L), the loading rates of cadmium and lead in house dust
(0.29 vs. 0.12 and 7.52 vs. 3.62 ng/cm2/92 days), and the vegetable indexes
(0.31 vs. −0.44 and 0.13 vs. −0.29 standardized units) were significantly higher
in the contaminated area. A two-fold increase in the metal loading rate in house
dust was associated with increases (P<0.001) in blood cadmium (+2.3%), 24-h
urinary cadmium (+3.0%), and blood lead (+2.0%), independent of the vegetable
index and other covariates. The estimated effect sizes on the biomarkers of
internal exposure were three times greater for house dust than vegetables. In
conclusion, in the adult population, house dust is potentially an important
route of exposure to heavy metals in areas with contaminated soils, and should
be incorporated in the assessment of health risks. Notes: Environ Res.
2006 Jul 12
Title:Mass transfer of soil indoors by track-in on
footwear Author: Andrew Hunt,David L. Johnsonb and Daniel A.
Griffith Abstract:nadvertent soil ingestion, especially by young
children, can be an important route of exposure for many environmental
contaminants. The introduction of exterior soil into the interior environment is
a significant element of the exposure pathway. The unintentional collection of
outside soil on footwear followed by subsequent deposition indoors is a
principal route of soil ingress. Here we have investigated likely rates of dry
and wet soil deposition on indoor hard surface flooring as a result of mass
transfer from soiled footwear. In this pilot study, testing involved both single
track-in events (with deposition resulting from a single progression of transfer
steps) and multiple tracking actions (with deposition and dispersion resulting
from repeated transfer steps). Based on soil mass recovery from the floor
surface it was found that any contamination introduced by one-time track-in
events was of limited spatial extent. In contrast, under repeated tracking
conditions, with multiple soil incursions, widespread floor surface
contamination was possible. Soil mass recovery was accomplished by brushing, by
vacuum cleaner removal and by wet wiping. All the clean-up methods operated
imperfectly and failed to remove all initially deposited soil. The level of
floor surface soiling that resulted from the track-in tests, and the incomplete
clean-up strongly suggest that under unrestricted transfer conditions rapid
accumulation and dispersal of soil on indoor flooring is
likely. Notes: Science of the Total Environment.
doi:10.1016/j.scitotenv.2006.07.013
Reference Type: Journal
Article Record Number: 16 Author: Hynes, H. P.; Maxfield,
R.; Carroll, P.; Hillger, R. Title: Dorchester Lead-Safe Yard project:
a pilot program to demonstrate low-cost, on-site techniques to reduce exposure
to lead-contaminated soil Pages: 199-211, 2001 Mar. Accession
Number: 11368198 Abstract: Despite a general reduction in blood
lead levels in children after lead was banned in gasoline and paint, lead
poisoning remains an important health problem in many older urban areas. One
factor that increases risk in these places is the high levels of lead in certain
residential areas. A major intervention study found that reducing lead levels in
urban soils results in a reduction in exposed children's blood lead levels.
Removing lead from inner-city soils or reducing exposures to lead-contaminated
soils typically is expensive, technologically challenging, or beyond the ability
of low-income households to undertake. This project, in conjunction with
residents and community-based institutions, developed a series of in situ,
low-cost, low-technology measures that worked to reduce the exposure to
lead-contaminated soils in one Boston, Massachusetts, neighborhood. The project
demonstrated several important results. Government, universities, residents, and
community based organizations can work together effectively to reduce exposures
to lead in soil. Lead-contaminated soil can be mitigated at a fraction of the
cost of conventional methods in ways that increase the ability of residents,
community health centers, and others to have a positive impact on their
neighborhoods. A lead-safe yard program can be replicated and institutionalized
by municipal home de-leading programs and other community
organizations. Notes: Journal of Urban Health. 78(1) Journal
Article
Reference Type: Journal Article Record Number:
48 Author: Jacobsen, P. Title: [Exposure of children to lead
from contaminated soil] Pages: 1499-502, 1996 Mar 11. Accession
Number: 8644394 Abstract: To assess lead exposure in infants from
contaminated soil a review of epidemiological studies was performed. Seventeen
studies fulfilled criteria of individual exposure measures and a relevant
confounder control. In 10 of these a clear association between blood lead and
lead in soil was demonstrated after control of confounders. With some
reservations three additional studies indicated an effect. No effect on blood
lead from soil exposure was found in four studies. Quantitative estimates of the
contributions to blood lead from soil varied within a wide range. In the best
designed study-a controlled intervention against contaminated soil-blood lead
values declined a little more than 1 microgram/100 ml per 1000 ppm. reduction of
soil lead concentration. Oral exposure, probably by mouthing behaviour, was
indicated by modification of the association between blood and soil lead from
time spent outdoors, area with uncovered soil, age and mouthing behaviour in
several studies. The conclusions from the review were that children's mouthing
behaviour on lead contaminated soil may affect blood lead, but the contribution
to overall lead exposure seems to be relatively small. Considering the limited
margin of safety for lead exposure an intervention regimen for contaminated
areas where infants have direct and continued contact with soil is suggested.
Intervention in other places is unlikely to significantly reduce the lead burden
of children. Simultaneously with intervention a programme for the evaluation of
its effect is proposed. [References: 22] Notes: Review Ugeskrift
for Laeger. 158(11) Journal Article Review,
Tutorial
Reference Type: Journal Article Record
Number: 38 Author: Jin, A.; Teschke, K.; Copes,
R. Title: The relationship of lead in soil to lead in blood and
implications for standard setting Pages: 23-40, 1997 Dec
3. Accession Number: 9496646 Abstract: As part of a soil
lead regulation process, this review was conducted to determine the association
between lead in soil and established human health effects of lead or validated
biomarkers of lead exposure. We reviewed only studies where soil exposure could
be distinguished from other sources of lead and whose design could reasonably be
used to infer a causal relationship between soil lead and either biomarkers or
health effects. No such studies of health effects were found. Studies describing
a quantitative relationship between soil lead and blood lead did meet our
criteria: 22 cross-sectional studies in areas with polluted soil; and three
prospective studies of soil lead pollution abatement trials. The cross-sectional
studies indicated that, compared to children exposed to soil lead levels of 100
ppm, those exposed to levels of 1000 ppm had mean blood lead concentrations
1.10-1.86 times higher and those exposed to soil lead levels of 2000 ppm had
blood lead concentrations 1.13-2.25 times higher. The prospective studies showed
effects within the ranges predicted by the cross-sectional studies. Differences
in results between studies were surprisingly modest and likely explainable by
random sampling error, different explanatory variables included in data analyses
and differences in methods of measuring lead in environmental
specimens. Notes: Science of the Total Environment.
208(1-2) Journal Article Meta-Analysis
Author:Johnson D,
Bretsch J. 2002. Soil lead and children's BLL Levels in Syracuse, NY, USA.
Environ Geochem Health 24(4):375-385. Abstract: A geo-referenced data
set of 12 228 first-time blood lead screening values for Syracuse, NY, children
was established for the 4-year period 1992-1996. Soil lead values were measured
in a 600 m by 600 m tessellation grid covering the city. The two data sets were
merged for evaluation of relationships between them. Strong seasonal variation
in blood lead levels suggests the importance of contaminated soils as an
exposure source. When the data were aggregated at a large geographic scale (3
km2), a logarithmic model showed an R2 of > 0.65 for the regression of
geometric mean blood lead on median soil lead values. Results showed a striking
similarity to those obtained by Mielke et al. (1999) for a study in New Orleans,
LA, USA.
Author:George D. Kamenov
Title:High-precision Pb isotopic measurements of teeth and
environmental samples from Sofia (Bulgaria): insights for regional lead
sources and possible pathways to the human body Notes:Environmental Geology. Volume 55, Number 3 / August, 2008. DOI 10.1007/s00254-007-1017-y. p. 669-680
Abstract:High-precision Pb isotopic measurements on teeth
and possible sources in a given area can provide important insights for
the lead (Pb) sources and pathways in the human body. Pb isotopic
analyses on soils from the area of Sofia, Bulgaria show that Pb is
contributed by three end-members represented by two natural sources and
leaded gasoline. Sequential leaching experiments reveal that the
alumosilicate fraction of the soils is mainly controlled by natural Pb
derived from two mountain massifs bordering the city. Around 1/3 to a
half of the Pb in the soil leachates, however, can be explained by
contamination from leaded gasoline. Contemporary teeth from Sofia
residents show very similar Pb isotopic compositions to the soil
leachates, also indicating that around 1/3 to a half of the Pb can be
explained by derivation from leaded gasoline. The remarkable isotopic
similarities between the teeth and the most labile fractions of the
local soils suggest that the lead can be derived from the latter. Pb
incorporation in the human body via soil-plant human or
soil plant animal human chains is unlikely due to the fact that no
significant farming occurs in the city area. The isotopic compositions
of the local soil labile fractions can be used as approximation of the
bioaccessible lead for humans. Considering all possible scenarios it
appears that soil and/or soil-born dust inhalation and/or ingestion is
the most probable pathway for incorporation of local soil lead in the
local population. The high-precision Pb isotope data presented in this
work indicate that apparently the local soil is what plays major role
in the human Pb exposure.
Author:Kurkjian R, Flegal AR. 2003. Isotopic evidence of
the persistent dominance of blood lead concentrations by previous gasoline lead
emissions in Yerevan, Armenia. Environ Res
93(3):308-315. Abstract:Recent (1999) blood lead (PbB) isotopic
compositions (n=17) of males and females in Yerevan, Armenia, indicate that
previous emissions of leaded gasoline still dominate the populace's PbB
concentrations 2 years after the country's apparent de facto elimination of
leaded gasoline in Armenia. The range of PbB isotopic compositions overlaps
those of air and near-road surface soils in Yerevan, and the averages of those
isotopic compositions in blood (208Pb/207Pb=2.442; 206Pb/207Pb=1.158) and
near-road soils (208Pb/207Pb=2.442; 206Pb/207Pb=1.157) are indistinguishable.
Using a proxy for historic leaded-gasoline emissions in Armenia, these analyses
suggest that leaded gasoline was, is, and will continue to be via the
resuspension of lead-bound soils contaminated by previous depositions from
leaded-gasoline emissions, a relatively important source of industrial lead in
both Yerevan's atmosphere and its populace. However, the level of lead
contamination in the Armenian populace, based on the PbB geometric mean of 4.0
ug/dL (n=49) measured in this initial survey, appears to be much lower than
recently proposed by the Armenian Ministry of Nature
Protection.
Author:D A V I D W . L A Y T O N A N D
P A L O M A I . B E A M E R * 2009. Migration of Contaminated Soil and
Airborne Particulates to Indoor Dust Environ. Sci. Technol. 2009, 43, 8199-8205 Abstract:
We have developed a modeling and measurement framework
for assessing transport of contaminated soils and airborne
particulates intoaresidence, their subsequent distribution indoors
via resuspension and deposition processes, and removal by
cleaning and building exhalation of suspended particles. The
model explicitly accounts for the formation of house dust as a
mixture of organic matter (OM) such as shed skin cells and
organic fibers, soil tracked-in on footwear, and particulate matter
(PM) derived from the infiltration of outdoor air. We derived
formulas for use with measurements of inorganic contaminants,
crustal tracers, OM, and PM to quantify selected transport
parameters. Application of the model to residences in the U.S.
Midwest indicates that As in ambient air can account for
nearly 60% of the As input to floor dust, with soil track-in
representing the remainder. Historic data on Pb contamination
in Sacramento, CA, were used to reconstruct sources of Pb
in indoor dust, showing that airborne Pb was likely the dominant
source in the early 1980s. However, as airborne Pb levels
declineddueto the phase-out ofleadedgasoline, soil resuspension
and track-in eventually became the primary sources of Pb in
house dust.
Reference Type: Journal Article Record
Number: 89 Author:Laidlaw, M.A., Zahran, S., Mielke, H.W., Taylor, M.P., Filippelli, G.M.
ReferenceLaidlaw, M.A., Zahran, S., Mielke, H.W., Taylor, M.P., Filippelli, G.M.,
Re-suspension of lead contaminated urban soil as a dominant source of atmospheric lead in
Birmingham, Chicago, Detroit and Pittsburgh, USA, Atmospheric Environment (2011), doi: 10.1016/
j.atmosenv.2011.11.030 AbstractSoils in older areas of cities are highly contaminated by lead, due largely to past use of lead additives in gasoline, the use of lead in exterior paints, and industrial lead sources. Soils are not passive repositories and periodic re-suspension of fine lead contaminated soil dust particulates (or aerosols) may create seasonal variations of lead exposure for urban dwellers. Atmospheric soil and lead aerosol data from the Interagency Monitoring of Protected Visual Environments (IMPROVE) database were obtained for Pittsburgh (Pennsylvania), Detroit (Michigan), Chicago (Illinois), and Birmingham (Alabama), USA. In this study the temporal variations of atmospheric soil and lead aerosols in these four US cities were examined to determine whether re-suspended lead contaminated urban soil was the dominant source of atmospheric lead. Soil and lead-in-air concentrations were examined to ascertain whether lead aerosols follow seasonal patterns with highest concentrations during the summer and/or autumn. In addition, atmospheric soil and lead aerosol concentrations on weekends and Federal Government holidays were compared to weekdays to evaluate the possibility that automotive turbulence results in re-suspension of lead contaminated urban soil. The results show that the natural logs of atmospheric soil and lead aerosols were associated in Pittsburgh from April 2004 to July 2005 (R2 = 0.31, p < 0.001), Detroit from November 2003 to July 2005 (R2 = 0.49, p = < 0.001), Chicago from November 2003 to August 2005 (R2 = 0.33, p = < 0.001), and Birmingham from May 2004 to December 2006 (R2 = 0.47, p <0.001). Atmospheric soil and lead aerosols followed seasonal patterns with highest concentrations during the summer and/or autumn. Atmospheric soil and lead aerosols are 3.15 and 3.12 times higher, respectively, during weekdays than weekends and Federal Government holidays, suggesting that automotive traffic turbulence plays a significant role in re-suspension of contaminated roadside soils and dusts. In order to decrease urban lead aerosol concentrations, lead deposition and subsequent children’s seasonal exposure, lead contaminated urban soils need remediation or isolation because the legacy of lead continues to pose unnecessary and preventable health risks to urban dwellers.
Reference Type: Journal Article Record
Number: 89 Author:Laidlaw M.A.S. and Taylor P.
Title: Potential for childhood lead poisoning in the inner cities of Australia
due to exposure to lead in soil dust Abstract This article presents evidence demonstrating that the historical use of leaded gasoline and lead (Pb) in
exterior paints in Australia has contaminated urban soils in the older inner suburbs of large cities such as
Sydney and Melbourne. While significant attention has been focused on Pb poisoning in mining and
smelting towns in Australia, relatively little research has focused on exposure to Pb originating from
inner-city soil dust and its potential for childhood Pb exposures. Due to a lack of systematic blood lead
(PbB) screening and geochemical soil Pb mapping in the inner cities of Australia, the risks from environmental
Pb exposure remain unconstrained within urban population centres.
Journal: Environmental Pollution
Reference Type: Journal Article Record
Number: 89 Author: Laidlaw, M. A.; Mielke, H. W.; Filippelli, G.
M.; Johnson, D. L.; Gonzales, C. R. Title:Seasonality and children's
blood lead levels: developing a predictive model using climatic variables and
blood lead data from Indianapolis, Indiana, Syracuse, New York, and New Orleans,
Louisiana (USA) Pages: 793-800, 2005 Jun. Accession Number:
15929906 Abstract: On a community basis, urban soil contains a
potentially large reservoir of accumulated lead. This study was undertaken to
explore the temporal relationship between pediatric blood lead (BPb), weather,
soil moisture, and dust in Indianapolis, Indiana; Syracuse, New York; and New
Orleans, Louisiana. The Indianapolis, Syracuse, and New Orleans pediatric BPb
data were obtained from databases of 15,969, 14,467, and 2,295 screenings,
respectively, collected between December 1999 and November 2002, January 1994
and March 1998, and January 1998 and May 2003, respectively. These average
monthly child BPb levels were regressed against several independent variables:
average monthly soil moisture, particulate matter < 10 microm in diameter
(PM10), wind speed, and temperature. Of temporal variation in urban children's
BPb, 87% in Indianapolis (R2 = 0.87, p = 0.0004), 61% in Syracuse (R2 = 0.61, p
= 0.0012), and 59% in New Orleans (R2 = 0.59, p = 0.0000078) are explained by
these variables. A conceptual model of urban Pb poisoning is suggested: When
temperature is high and evapotranspiration maximized, soil moisture decreases
and soil dust is deposited. Under these combined weather conditions, Pb-enriched
PM10 dust disperses in the urban environment and causes elevated Pb dust
loading. Thus, seasonal variation of children's Pb exposure is probably caused
by inhalation and ingestion of Pb brought about by the effect of weather on
soils and the resulting fluctuation in Pb loading. Notes:
Environmental Health Perspectives. 113(6)
Author: Laidlaw, M. A. S. ; Filippelli, G.
M. Title:Reducing The Lead-Load For Urban Youth: The Role Of
Atmospheric Soil Re-suspension as a Significant Public Health Threat In The
United States Abstract: Children's lead poisoning in urban areas in
the United States follows a seasonal pattern with a peak in the summer months.
We recently found that that weather and soil moisture variables robustly
predicted seasonal changes in children's blood lead levels in a number of US
cities. We concluded that the weather and soil moisture variables were a proxy
of seasonal soil re-suspension and exposure of children to lead contaminated
urban soils, with the potential to use site-specific weather and soil moisture
determinations to better assess clinical blood Pb data. In order to test the
hypothesis that atmospheric soil concentrations display a seasonal pattern, time
series of atmospheric soil concentrations were obtained at eight IMPROVE
locations across the United States. Results indicate that continental
atmospheric soil concentrations exhibit strong seasonality and increase up to an
order of magnitude between winter (minimum) and summer (maximum). In order to
test the hypothesis that atmospheric soil seasonality is related to weather and
soil moisture variables, atmospheric soil concentrations at the Bondville,
Illinois IMPROVE site were regressed against the independent variables minimum
relative humidity, field measured soil moisture, precipitation, temperature,
wind speed, atmospheric pressure, while adjusting for the month of the year. The
model time period was 37 months. Results indicate that eighty-three percent of
the temporal variation of atmospheric soil concentrations (R2=0.83, p =
<0.001, DW = 2.06), could be explained by these variables. Our empirical
model indicates that when temperatures are high, relative humidity is low, and
evapotranspiration maximized, soil moisture decreases, and soil dust is
re-suspended into the atmosphere. Correlation of local atmospheric soil
concentrations with local soil moisture and atmospheric data suggests that a
significant proportion of the atmospheric soil is derived from local sources.
The findings that weather and soil moisture variables predict atmospheric soil
seasonality (this study) and children's blood lead levels (our previous work)
support the hypothesis that seasonal re-suspension of local lead contaminated
soils in urban environments is driving seasonal lead poisoning.
Notes:Geological Society of America Annual Meeting (Philadelphia;
22�25 October 2006.)
Author: Laidlaw, M. A. S. ; Filippelli, G.
M. Title:Resuspension of urban soils as a persistent source of lead poisoning in children: A review and new
directions
Abstract:
Urban soils act as the repository for a number of environmental burdens, including Pb. Significant
attention has been devoted to reducing Pb burdens to children with outstanding success, but the fact that
blood Pb levels above 10 μg/dL are disproportionately found in children living in many U.S.A. cities (15-20%
in some cities compared to a national average of less than 2%) indicates that not all of the sources have
been eliminated. Although the health risk of fine particulates has begun to raise concerns in cities, little
attention has been paid to Pb associated with these particulates and the potential role of this pathway for
continued Pb burdens of urban youth. This review summarizes recent work on particulate resuspension and
the role of resuspension of Pb-enriched urban soils as a continued source of bioavailable Pb both outside
and inside homes, then presents recent efforts to model Pb burdens to children based on the atmospheric
parameters that drive particulate resuspension. A strong seasonal relationship is found between
atmospheric particulate loading and blood Pb levels in children, and new particulate loading models are
presented for a range of U.S. cities involved in the Interagency Monitoring of Protected Visual Environments
(IMPROVE) program. These seasonal particulate loading models have implications for a number of
respiratory health impacts, but can also be used to calculate seasonal patterns in bioavailable Pb
redistribution onto contact surfaces (the primary pathway for ingestion-related uptake in toddlers) and assist
clinicians in interpreting time-specific blood Pb tests. Notes:Applied Geochemistry, 2008 (Accepted)
Author: Laidlaw, M. A. S.
Title: Correlation of Atmospheric Soil and Atmospheric Lead
in Three North American Cities: Can Re-suspension of Urban Lead
Contaminated Soil be a Major Source of Urban Atmospheric Lead and Cause
Seasonal Variations in Children�s Blood Lead Levels?
Source: 24th International Applied Geochemistry Symposium (IAGS). Fredericton, New Brunswick, Canada(June 1st to June 4th, 2009)
Abstract: Soils in older cities are highly contaminated
by lead from past use of lead in leaded gasoline and due to the use of
lead in exterior paints. In this study the temporal variations in
atmospheric soil and atmospheric lead in three North American cities
are examined. This study tested the hypothesis that atmospheric lead
and atmospheric soil concentrations obtained from the Interagency
Monitoring of Protected Visual Environments (IMPROVE) exhibit
statistically significant correlations in three North American cities.
Results indicate that atmospheric soil and atmospheric lead were
correlated in Detroit between November 2003 to July 2005 (r = 0.47, p =
< 0.001); In Pittsburgh between April 2004 to July (r = 0.40, p <
0.001); and in Birmingham between May 2004 to December 2006 (r = 0.35,
p <0.001). The hypothesis that atmospheric soil and atmospheric lead
follow seasonal patterns with highest concentrations during the summer
and/or autumn could not be rejected. It is suggested that atmospheric
lead and atmospheric soil concentrations are correlated due to
re-suspension of urban lead contaminated soils. It is further suggested
that in order to decrease urban atmospheric lead concentrations, lead
deposition, and children's seasonal exposure via hand to mouth
activity, urban lead contaminated soils should be remediated or
isolated.
Author: Lambert, Timothy
W. and Lane,Stephanie. 2004.Lead, Arsenic, and Polycyclic Aromatic Hydrocarbons
in Soil and House Dust in the Communities Surrounding the Sydney, Nova Scotia,
Tar Ponds. Environmental Health Perspectives Volume 112, Number 1, January
2004 Abstract: This study evaluated lead, arsenic, and polycyclic
aromatic hydrocarbon (PAH) contamination in the residential communities adjacent
to the Sydney, Nova Scotia, tar ponds, the area considered Canada's worst
contaminated site. The tar pond remediation policy has been limited to the site
and some residential properties. We compared background concentrations in 91
soil samples taken 5-20 km from the coke oven site with those in soil samples
from the three communities surrounding the tar ponds: Whitney Pier, Ashby, and
North End. These surrounding communities were statistically different from
background regarding arsenic, lead, and PAHs. Twenty percent of the background
soil samples and 95% of the tar pond soil samples were above the Canadian
health-risk-based soil guidelines for arsenic (12 ppm), and 5% of the background
samples and 80% of the tar pond soil samples were above the Canadian guidelines
for lead (140 ppm). Regarding dust lead and arsenic loading, the results provide
no evidence that Whitney Pier is significantly different than Ashby and North
End. Children in these communities are predicted to have a 1-15% chance of blood
lead > 10 ug/dL. The results suggest that lead and arsenic found in the homes
originate outside. The lead content of paint in the homes was not evaluated, but
consideration of painted wood at the doorway did not confound the results of the
study. The results indicate that the residential environment has been adversely
affected by PAHs, lead, and arsenic and should be considered for remediation.
Key words: arsenic, community, environmental justice, house dust, lead, PAHs,
polycyclic aromatic hydrocarbons, soil, Sydney, tar ponds, tracking.
Reference Type: Journal Article Record Number:
50 Author: Langlois, P.; Smith, L.; Fleming, S.; Gould, R.; Goel, V.;
Gibson, B. Title: Blood lead levels in Toronto children and abatement
of lead-contaminated soil and house dust Pages: 59-67, 1996
Jan-Feb. Accession Number: 8629866 Abstract: South Riverdale
in Toronto, Canada, underwent a lead-abatement program. In 1988,
lead-contaminated soil was replaced at 970 properties, and in 1989, professional
housecleaning for lead removal was conducted in 717 households. The effect of
"abatement" on blood lead levels in young children was investigated. Data were
analyzed from 12 cross-sectional blood-screening surveys that were conducted
during an 8-y period in South Riverdale and in two comparison areas. Responses
regarding behavioral, household, lifestyle, neighborhood, and environmental
factors, all of which were gleaned from associated questionnaires, were also
analyzed. Response rates varied between 32% and 75%. During the years between
1984 and 1992, blood lead decreased in all study areas. There appeared to be a
minimal blood lead level of 2-3 micrograms/dl for urban Ontario children who
were less than 6 y of age. The significant difference between South Riverdale
and the control areas disappeared by 1992. Although abatement activity in South
Riverdale was associated with an accelerated decline in blood lead levels, it
was difficult to distinguish this from effects of decreased Toronto air lead
levels or decreased smelter emissions. Within South Riverdale, abatement
appeared to be associated with a slower decline in blood lead levels over time,
likely the result of selection bias, soil mixing, or recontamination from the
smelter. No difference was observed between the separate effects of
housecleaning or soil replacement. The findings could neither strongly support
nor refute beneficial effects of abatement. Notes: Archives of
Environmental Health. 51(1) Journal Article
Reference Type: Journal Article Record Number:
36 Author: Lanphear, B. P.; Burgoon, D. A.; Rust, S. W.; Eberly, S.;
Galke, W. Title: Environmental exposures to lead and urban children's
blood lead levels Pages: 120-30, 1998 Feb. Accession Number:
9515067 Abstract: Lead-contaminated water, soil, and paint have been
recognized as potential sources of children's lead exposure for decades, but
their contributions to lead intake among urban children remain poorly defined.
This analysis was undertaken to estimate the relationship of environmental lead
exposures to lead intake among a random sample of urban children, adjusted for
exposure to lead-contaminated house dust. Analyses of 183 urban children
enrolled in a random sample, cross sectional study were conducted. Children's
blood and multiple measures of household dust, water, soil, and paint were
analyzed for lead, and interviews were conducted to ascertain risk factors for
childhood lead exposure. Environmental sources of lead, including house-dust,
soil lead, and water lead, were independently associated with children's blood
lead levels. In contrast, paint lead levels did not have a significant effect on
blood lead levels after adjusting for other environmental exposures. An increase
in water lead concentration from background levels to 0.015 mg/L, the current
EPA water lead standard, was associated with an increase of 13.7% in the
percentage of children estimated to have a blood lead concentration exceeding 10
micrograms/dL; increasing soil lead concentration from background to 400
micrograms/g was estimated to produce an increase of 11.6% in the percentage of
children estimated to have a blood lead level exceeding 10 micrograms/dL, and
increasing dust lead loading from background to 200 micrograms/ft2 is estimated
to produce an increase of 23.3% in the percentage of children estimated to have
a blood lead level exceeding 10 micrograms/dL. These data support the
promulgation of health-based standards for lead-contaminated dust and soil and
the progressive lowering of standards for lead-contaminated water as the
definition of undue lead exposure has been modified. Notes:
Environmental Research. 76(2) Journal Article
Reference
Type: Journal Article Record Number: 33 Author:
Lanphear, B. P.; Matte, T. D.; Rogers, J.; Clickner, R. P.; Dietz, B.;
Bornschein, R. L.; Succop, P.; Mahaffey, K. R.; Dixon, S.; Galke, W.;
Rabinowitz, M.; Farfel, M.; Rohde, C.; Schwartz, J.; Ashley, P.; Jacobs, D.
E. Title: The contribution of lead-contaminated house dust and
residential soil to children's blood lead levels. A pooled analysis of 12
epidemiologic studies Pages: 51-68, 1998 Oct. Accession
Number: 9756680 Abstract: In 1992, the U.S. Congress passed the
Residential Lead-Based Paint Hazard Reduction Act, which requires the
promulgation of health-based dust lead and soil lead standards for residential
dwellings to prevent undue lead exposure in children. Unfortunately, the levels
of lead in house dust and soil that are associated with elevated blood lead
levels among U.S. children remain poorly defined. This pooled analysis was done
to estimate the contributions of lead-contaminated house dust and soil to
children's blood lead levels. The results of this pooled analysis, the most
comprehensive existing epidemiologic analysis of childhood lead exposure,
confirm that lead-contaminated house dust is the major source of lead exposure
for children. These analyses further demonstrate that a strong relationship
between interior dust lead loading and children's blood lead levels persists at
dust lead levels considerably below the U.S. Department of Housing and Urban
Development's current postabatement standards and the Environmental Protection
Agency's guidance levels. Finally, these analyses demonstrate that a child's
age, race, mouthing behaviors, and study-site specific factors influence the
predicted blood lead level at a given level of exposure. These data can be used
to estimate the potential health impact of alternative health-based lead
standards for residential sources of lead exposure. Notes:
Environmental Research. 79(1) Journal
Article Meta-Analysis
Reference Type: Journal
Article Record Number: 40 Author: Lanphear, B. P.; Roghmann,
K. J. Title: Pathways of lead exposure in urban
children Pages: 67-73, 1997. Accession Number:
9339217 Abstract: A linear structural equation modeling procedure was
used to explore the mechanisms and pathways for lead intake among urban children
and the relative contribution of various lead sources to lead-contaminated house
dust. Dust lead levels were significantly associated with children's blood lead
levels, both indirectly and directly via hand lead. Both soil and paint lead
contributed to dust lead levels, but paint contributed significantly more lead
to house dust than soil (P < 0.001). Black race and income level both
directly affected children's blood lead levels. Finally, time spent outdoors was
associated with children putting soil or dirt in their mouths which was, in
turn, associated with children's blood lead levels. These data indicate that
mouthing behaviors are an important mechanism of exposure among urban children
with low-level elevations in blood lead and that lead-based paint is a more
important contributor of lead to house dust than is lead-contaminated
soil. Notes: Environmental Research. 74(1) Journal
Article
Reference Type: Journal Article Record Number:
5 Author: Lanphear, B. P.; Succop, P.; Roda, S.; Henningsen,
G. Title: The effect of soil abatement on blood lead levels in
children living near a former smelting and milling operation.[see
comment] Pages: 83-91, 2003 Mar-Apr. Accession Number:
12690062 Abstract: OBJECTIVE: To evaluate the effect of soil abatement
on children's blood lead concentrations and on environmental levels of lead and
arsenic. METHODS: Two cross-sectional surveys were conducted. The first (1989)
was of a random sample of 6- to 72-month-old children (n=112). The second (1998)
included all 6- to 72-month-old children whose parents agreed to participate in
the survey (n=215). From 1993 to 1996, soil abatement was conducted around homes
with average soil lead concentration >500 parts per million (ppm).
Venipuncture blood samples were taken, interviews were conducted, and samples of
house dust, soil, water, and paint were tested for lead and arsenic, using
identical protocols in both surveys. The expected decline in blood lead
concentrations were calculated for children who lived in houses that were
abated, compared with children who lived in houses that were not abated.
RESULTS: Lead and arsenic in soil and interior dust in homes that underwent soil
abatement declined significantly compared to unabated homes (p<.05). After
adjustment for potential confounders, the blood lead concentration in children
ages 6 to 72 months who lived in soil-abated housing declined 42.8% faster than
children who lived in unabated housing (p=0.14). In children ages 6 to 36
months, the decline was 45.4% faster (p=0.03). The estimated reduction in blood
lead for children ages 6 to 36 months was 3.5 micro g/dL for every 1,000 ppm
reduction in soil lead concentration (95% confidence interval [CI]=2.4 micro
g/dL, 4.6 micro g/dL). CONCLUSION: Soil abatement was associated with a
significant decline in children's blood lead and indoor environmental levels of
lead and arsenic. Notes: Public Health Reports. 118(2) Journal
Article
Author: Bruce P. Lanphear, David A. Burgoon, Steven W. Rust,
Shirley Eberly and Warren Galke Title:Environmental Exposures to Lead
and Urban Children's Blood Lead Levels Abstract: Lead-contaminated
water, soil, and paint have been recognized as potential sources of children's
lead exposure for decades, but their contributions to lead intake among urban
children remain poorly defined. This analysis was undertaken to estimate the
relationship of environmental lead exposures to lead intake among a random
sample of urban children, adjusted for exposure to lead-contaminated house dust.
Analyses of 183 urban children enrolled in a random sample, cross sectional
study were conducted. Children's blood and multiple measures of household dust,
water, soil, and paint were analyzed for lead, and interviews were conducted to
ascertain risk factors for childhood lead exposure. Environmental sources of
lead, including house-dust, soil lead, and water lead, were independently
associated with children's blood lead levels. In contrast, paint lead levels did
not have a significant effect on blood lead levels after adjusting for other
environmental exposures. An increase in water lead concentration from background
levels to 0.015 mg/L, the current EPA water lead standard, was associated with
an increase of 13.7% in the percentage of children estimated to have a blood
lead concentration exceeding 10 μg/dL; increasing soil lead concentration from
background to 400 μg/g was estimated to produce an increase of 11.6% in the
percentage of children estimated to have a blood lead level exceeding 10 μg/dL,
and increasing dust lead loading from background to 200 μg/ft2is estimated to
produce an increase of 23.3% in the percentage of children estimated to have a
blood lead level exceeding 10 μg/dL. These data support the promulgation of
health-based standards for lead-contaminated dust and soil and the progressive
lowering of standards for lead-contaminated water as the definition of undue
lead exposure has been modified. Notes: Environmental Research Volume
76, Issue 2 , February 1998, Pages 120-130
Reference Type:
Journal Article Record Number: 46 Author: Lanphear, B. P.;
Weitzman, M.; Winter, N. L.; Eberly, S.; Yakir, B.; Tanner, M.; Emond, M.;
Matte, T. D. Title: Lead-contaminated house dust and urban children's
blood lead levels Pages: 1416-21, 1996 Oct. Accession
Number: 8876511 Abstract: OBJECTIVES: This study assessed the
relationship between lead-contaminated house dust and urban children's blood
lead levels. METHODS: A random-sample survey was used to identify and enroll 205
children, 12 to 31 months of age, who had resided in the same house since at
least 6 months of age. Children's blood and household dust, water, soil, and
paint were analyzed for lead, and interviews were conducted to ascertain risk
factors for elevated blood lead (> or = 10 micrograms/dL). RESULTS:
Children's mean blood lead level was 7.7 micrograms/dL. In addition to dust lead
loading (micrograms of lead per square foot), independent predictors of
children's blood lead were Black race, soil lead levels, ingestion of soil or
dirt, lead content and condition of painted surfaces, and water lead levels. For
dust lead standards of 5 micrograms/sq ft, 20 micrograms/sq ft, and 40
micrograms/sq ft on noncarpeted floors, the estimated percentages of children
having blood lead levels at or above 10 micrograms/dL were 4%, 15%, and 20%,
respectively, after adjusting for other significant covariates. CONCLUSIONS:
Lead-contaminated house dust is a significant contributor to lead intake among
urban children who have low-level elevations in blood lead. A substantial
proportion of children may have blood lead levels of at least 10 micrograms/dL
at dust lead levels considerably lower than current standards. Notes:
American Journal of Public Health. 86(10) Journal
Article
Reference Type: Journal Article Record
Number: 47 Author: Lanphear, B. P.; Winter, N. L.; Apetz, L.;
Eberly, S.; Weitzman, M. Title: A randomized trial of the effect of
dust control on children's blood lead levels Pages: 35-40, 1996
Jul. Accession Number: 8668409 Abstract: OBJECTIVE. Dust
control is recommended as one of the cornerstones of controlling childhood lead
exposure; however, the effectiveness of dust control has not been demonstrated
for children who have low to mild elevations in blood lead (ie, less than 25
micrograms/dL). The objective of this study was to determine whether dust
control, as performed by families, had an effect on children's blood lead levels
and dust lead levels in children's homes. DESIGN. Randomized, controlled trial.
SETTING. Community-based trial in Rochester, NY. PARTICIPANTS. One hundred four
children, 12 to 31 months of age at baseline. INTERVENTION. Families and
children were randomized to one of two groups. Families of children in the
intervention group received cleaning supplies, information about cleaning areas
that are often contaminated with lead, and a cleaning demonstration. Families in
the control group received only a brochure about lead poisoning prevention.
OUTCOME MEASURES. Baseline measurements of lead in blood, house dust, soil,
water, and paint were taken from both groups. Seven months after enrollment, a
second blood lead assay was obtained, and lead levels in household dust were
measured. The main outcome measures were change in blood lead levels and dust
lead levels by treatment group. RESULTS. The median blood lead level of children
enrolled in the study was 6.7 micrograms/dL (range, 1.7 to 30.6 micrograms/dL).
There was no significant difference in the change of children's blood lead
levels or dust lead levels by treatment group. The median change in blood lead
levels among children in the intervention group was -0.05 micrograms/dL compared
with -0.60 micrograms/dL among those in the control group. There also was no
significant difference in the change of dust lead by group assignment, although
there was a trend toward a significant difference in the percentage of change in
dust lead levels on noncarpeted floors, which was greater among houses in the
intervention group. CONCLUSIONS. These data suggest that an intervention that
consists only of providing cleaning supplies and a brief description of dust
control is not effective at reducing blood lead levels among urban children with
low to mild elevations in blood lead levels at a 7-month
follow-up. Notes: Pediatrics. 98(1) Clinical Trial Journal
Article Randomized Controlled Trial
Reference Type: Journal
Article Record Number: 25 Author: Lewin, M. D.; Sarasua, S.;
Jones, P. A. Title: A multivariate linear regression model for
predicting children's blood lead levels based on soil lead levels: A study at
four superfund sites Pages: 52-61, 1999 Jul. Accession
Number: 10361026 Abstract: For the purpose of examining the
association between blood lead levels and household-specific soil lead levels,
we used a multivariate linear regression model to find a slope factor relating
soil lead levels to blood lead levels. We used previously collected data from
the Agency for Toxic Substances and Disease Registry's (ATSDR's) multisite lead
and cadmium study. The data included the blood lead measurements (0.5 to 40.2
microg/dL) of 1015 children aged 6-71 months, and corresponding
household-specific environmental samples. The environmental samples included
lead in soil (18.1-9980 mg/kg), house dust (5.2-71,000 mg/kg), interior paint
(0-16.5 mg/cm2), and tap water (0.3-103 microg/L). After adjusting for income,
education of the parents, presence of a smoker in the household, sex, and dust
lead, and using a double log transformation, we found a slope factor of 0.1388
with a 95% confidence interval of 0.09-0.19 for the dose-response relationship
between the natural log of the soil lead level and the natural log of the blood
lead level. The predicted blood lead level corresponding to a soil lead level of
500 mg/kg was 5.99 microg/kg with a 95% prediction interval of 2. 08-17.29.
Predicted values and their corresponding prediction intervals varied by
covariate level. The model shows that increased soil lead level is associated
with elevated blood leads in children, but that predictions based on this
regression model are subject to high levels of uncertainty and variability.
Copyright 1999 Academic Press. Notes: Environmental Research.
81(1) Journal Article
Reference Type: Journal
Article Record Number: 4 Author: Louekari, K.; Mroueh, U.
M.; Maidell-Munster, L.; Valkonen, S.; Tuomi, T.; Savolainen,
K. Title: Reducing the risks of children living near the site of a
former lead smeltery Pages: 65-75, 2004 Feb 5. Accession
Number: 14967502 Abstract: The sources of lead exposure, soil,
household dust, diet and ambient air near a former lead smeltery were studied.
The blood lead level of small children was also determined. The aim of the study
was to define, based primarily on blood lead measurements, whether children
living in the contaminated area may be at risk. Within 500 m from the site of
the smeltery, there were several areas where the Finnish limit value for soil
Pb, i.e. 300 mg/kg, was exceeded. In the recently built areas, the surface soil
has been replaced and soil remediation has taken place in schoolyards and the
playgrounds of children's day-care centres. Lead content in household dust was
clearly elevated in the contaminated areas. In approximately 20 years, after the
smeltery was closed in 1984, the lead concentrations of the fruits and berries
in local gardens have decreased to one-tenth. In some samples, the limit values
are still exceeded. The lead concentration in ambient air is now 50 times lower
than in the 1970s. The blood lead level of the children living in the area is
slightly but statistically significantly higher than that of the children in the
control areas. The critical blood lead level, i.e. 10 microg/100 ml, was not
exceeded in any of the children examined. The average and maximum lead
concentrations of 63 analysed blood samples were 2.2 and 5 microg/100 ml,
respectively. In contrast, the average and maximum blood lead levels of school
children in 1981 were 6.7 and 13.0 microg/100 ml, respectively. The risk
reduction measures undertaken during the past 20 years are
described. Notes: Science of the Total Environment.
319(1-3) Journal Article
Reference Type: Journal Article Record Number:
43 Author: Maisonet, M.; Bove, F. J.; Kaye, W. E. Title: A
case-control study to determine risk factors for elevated blood lead levels in
children, Idaho Pages: 67-72, 1997 Jan-Feb. Accession
Number: 9098951 Abstract: OBJECTIVE: A pair-matched, case-control
study was conducted to identify if risk factors or behaviors suspected to affect
childhood blood lead levels, were more prevalent among children with elevated
blood lead levels living in the vicinity of a defunct mining and smelting
facility. METHODS: Study individuals were recruited from the 1992 Silver Valley
blood lead screening participants. The cases were children with a blood lead
level > 10 micrograms per deciliter (microgram/dL). The controls were
children with a blood lead level < 10 micrograms/dL, who were matched to
cases by age and sex. Data on risk factors were obtained through personal
interviews. RESULTS: Of the variables examined, yard soil remediation showed the
strongest association with changes in blood lead levels. This variable was found
to be a protective factor for elevated blood lead levels in children (odds
ratio, 0.28; confidence interval, 0.08-0.92). CONCLUSION: The results suggest
that removal of lead contaminated soil from residential yards was effective in
reducing blood lead levels in children. Notes: Toxicology &
Industrial Health. 13(1) Journal Article
Reference Type: Journal Article Record Number:
12 Author: Malcoe, L. H.; Lynch, R. A.; Keger, M. C.; Skaggs, V.
J. Title: Lead sources, behaviors, and socioeconomic factors in
relation to blood lead of native american and white children: a community-based
assessment of a former mining area Pages: 221-31, 2002
Apr. Accession Number: 11929732 Abstract: Lead poisoning
prevention requires knowledge of lead sources and of appropriate residential
lead standards. Data are severely lacking on lead sources for Native American
children, many of whom live in rural areas. Further, the relation of mining
waste to blood lead concentrations (BPbs) of rural children is controversial. In
collaboration with the eight tribes of northeastern Oklahoma, we assessed lead
sources and their effects on BPbs for rural Native American and White children
living in a former mining region. Venous blood lead, residential environmental
(soil, dust, paint, water), and caregiver interview (e.g., hand-to-mouth
behaviors, socioeconomic conditions) data were obtained from a representative
sample of 245 children 1-6 years of age. BPbs ranged from 1 to 24 microg/dL.
There were no ethnic differences in BPbs (p= 0.48) nor any patterns of excess
lead sources for Native American or White children. Multiple linear regression
analyses indicated that mean soil lead, mean floor lead loading, mouthing
behaviors, caregivers' education, and residence in former mining towns were all
strongly associated with BPbs. Logistic regression results showed mean floor
dust lead loading greater than or equal to 10.1 microg/ft(2) (odds ratio [OR],
11.4; 95% confidence interval [CI], 3.5-37.3), and yard soil lead >165.3
mg/kg (OR, 4.1; CI, 1.3-12.4) were independently associated with BPbs greater
than or equal to 10 microg/dL. We also found strong interactions between soil
lead and poverty (p= 0.005), and dust and soil sources (p= 0.02). Our findings
indicate that soil and dust lead derived largely from mining waste pose a health
hazard to Native American and White children, and that current residential dust
lead standards are insufficient to adequately protect children. Moreover, our
finding that poor children are especially vulnerable to lead exposures suggests
that residential standards should consider interactions among socioeconomic
conditions and lead sources if environmental justice is to be
achieved. Notes: Environmental Health Perspectives. 110 Suppl
2 Journal Article
AuthorHoward W. Mielke, Mark A.S. Laidlaw, Chris Gonzales
Title:Lead (Pb) legacy from vehicle traffic in eight California urbanized areas: Continuing
influence of lead dust on children's health
AbstractThis article describes the magnitude of U.S. lead (Pb) additives in gasoline from 1927 to 1994 and estimated
quantities of Pb dispersed by vehicle traffic in eight urbanized areas (UAs) of California from 1950 to 1982.
The findings are the basis for predicting the health impact of Pb on children living in UA of California.
Quantitative U.S. national data for 1927-1994 were from the U.S. Senate hearing of the 1984 Airborne Lead
Reduction Act. Vehicle traffic data, fuel efficiency, percentage leaded gasoline, and quantities of Pb in gasoline
were obtained for 1982 from public and corporate records to estimate vehicle Pb emissions for small to very
large UAs of California. California fuel consumption records and yearly quantities of Pb additives per gallon
were the basis for estimating the 1950-1982 dispersion of Pb in each UA. Lead additives were calculated by
multiplying annual vehicle fuel used by average Pb per gallon. The proportion of Pb additive for each UA was
calculated from vehicle miles traveled (VMT) driven in 1982 divided by miles per gallon fuel consumption
times the ratio of leaded to unleaded fuel times Pb additive per gallon. U.S. Environmental Protection Agency
calculations of the fates of Pb were used to estimate Pb aerosol dispersal in each UA. About 108 billion miles
of travel in 1982 within 8 UAs accounts for 3200 metric tons of Pb additives or ∼60% total Pb additives in
California. Between the 1950-1982 peak of Pb additives, about 258,000 metric tons are accounted for out of
the state 412,000 metric tons total during the same time period. The estimates of the quantities of Pb dust
that accumulated within various UAs in California assists with predicting the continuing influences of Pb on
children's exposure. Mapping the soil Pb reservoir assists with establishing the priority for enhancing
environments of children.
NotesScience of the Total Environment, 2010.
Author:Howard W. Mielke, Mark A.S. Laidlaw, Chris R. Gonzales
Title:Estimation of leaded (Pb) gasoline's continuing material and health impacts
on 90 US urbanized areas
Abstract:The subject of this paper is lead (Pb) additives in gasoline and their material and health impact from Pb dust
inputs into 90 US urbanized areas (UAs). The mass of Pb additives for 90 UAs as a total of the US Pb additives
in 1982 were estimated from vehicle travel, vehicle fuel economy (miles/gallon), ratio of leaded to unleaded
fuel, and Pb/gallon. About 500 billion (109) miles of travel in 90 UA's during 1982 account for ~18,000 metric
tons (MT), or nearly 30% of the US Pb additives in 1982. Applying the 1982 proportions to the 90 UAs for
1950 through 1982 fuel sales by state accounts for ~1.4 million MT Pb of the US national total of 4.6 million
MT during the same years. Fates of Pb additives in engine systems were used to calculate Pb aerosol inputs
into the 90 UAs. The inputs range from 100's to more than 100,000 MT of Pb depending on a given UA's
traffic flow patterns. Soils are the reservoir of urban Pb dust. The median background soil Pb for the US is
16.5 mg/kg (range 10.3 to 30.1 mg/kg), and less by an order of magnitude or more than soil Pb within larger
UAs. Recognizing the US input of massive gasoline Pb additives into UAs assists with comprehending soil Pb
differences between large and small UAs, inner and outer areas of UAs, health disparities, and school
achievement issues within UAs. The findings underscore the need for controlling accumulated exterior urban
Pb dust from gasoline additives along with paint sources that have accumulated in soil to meet the goal of
primary childhood Pb exposure prevention.
Notes:Environment International, 2010.
Author:Howard W. Mielke,Eric T. Powell, Christopher R. Gonzales and Paul
W. Mielke, Jr. Title:Potential lead on play surfaces: Evaluation of
the PLOPS sampler as a new tool for primary lead
prevention Abstract:This New Orleans study tested the potential lead
on play surfaces (PLOPS) sampler, as a tool for measuring the potential lead
(Pb) surface loading per area (e.g., μg/ft2) of the soil. The PLOPS is a
cylindrical vinyl envelope filled with 1 kg (2.2 lbs) water. A wet wipe, the
same type as used for floor wipes, is clipped to the bottom of the cylindrical
vinyl envelope and placed on the soil and turned one quarter of a turn and back
to obtain a sample. PLOPS samples paired with one conventional soil lead (SL)
sample (amount of Pb per mass) up to 2.5 cm (1 in) deep were collected from 25
properties and 67-69 field sites before and after covering them with clean
Mississippi River alluvial soil from the Bonnet Carr Spillway (BCS).
Permutation methods were used to evaluate results. The correlation was 0.85
between Plops 1 and 2 and the agreement was 0.79 (P-values0.0000001, i.e.,
extreme). The averages of PLOPS duplicates were used to correlate PLOPS and SL.
The simplest mathematical expressions are in the forms y=a+bxc and x=d+eyf,
where x is PLOPS and y is SL. The results were:y=−7.42+0.408x0.97 and
x=−43.74+24.85y0.69. The agreements were 0.61 and 0.62, respectively
(P-value0.0000001). According to the relationship, when the PLOPS measure 40
μg/ft2, the predicted SL is 7.2 mg/kg. Also, when SL measures 400 mg/kg, 1508
μg/ft2 is predicted for PLOPS; therefore, SL concentration underestimates the
potential for Pb exposure from the soil surface. The PLOPS tool provides a
measurement that is comparable with interior floor wipes because it measures the
amount of Pb per area a child is likely to encounter while at play on the soil
surface. Notes:Environmental research.
doi:10.1016/j.envres.2006.08.007
Author: Howard W. Mielke,* Eric T. Powell, Christopher R. Gonzales, Paul
W. Mielke Jr., Rolf Tore Ottesen, and Marianne Langedal Title: New
Orleans Soil Lead (Pb) Cleanup Using Mississippi River Alluvium: Need,
Feasibility, and Cost Pages: DOI - 10.1021/es0525253
S0013-936X(05)02525-3 BR> Abstract: In New Orleans, LA prior to
hurricane Katrina 20-30% of inner-city children had elevated blood Pb levels 10
g/dL and 10 census tracts had a median surface soil level of Pb >1000 mg/kg
(2.5 times the U.S. standard). This project tests the feasibility of
transporting and grading contaminated properties (n = 25) with 15 cm (6 in.) of
clean Mississippi River alluvium from the Bonnet Carr Spillway (BCS) (median
soil Pb content 4.7 mg/kg; range 1.7-22.8). The initial median surface soil Pb
was 1051 mg/kg (maximum 19 627). After 680 metric tons (750 tons) of clean soil
cover was emplaced on 6424 m2 (69 153 ft2), the median surface soil Pb decreased
to 6 mg/kg (range 3-18). Interior entrance wipe samples were collected at 10
homes before and after soil treatment and showed a decreasing trend of Pb (p
value = 0.048) from a median of 52 g/ft2 to a median of 36 g/ft2 (25th and 75th
percentiles are 22 and 142 g/ft2 and 12 and 61 g/ft2, respectively). Average
direct costs for properties with homes were $3,377 ($1.95 per square foot), with
a range of $1,910-7,020, vs $2,622 ($0.61 per square foot), with a range of
$2,400-3,040 for vacant lots. Approximately 40% (86,000) of properties in New
Orleans are in areas of >400 mg Pb/kg soil and estimated direct costs for
treatment are between $225.5 and $290.4 million. Annual costs of Pb poisoning in
New Orleans are estimated at ~$76 million in health, education, and societal
harm. Urban accumulation of Pb is an international problem; for example, the new
Government of Norway established a policy precedence for an isolated soil
cleanup program at daycare centers, school playgrounds, and parks to protect
children. New Orleans requires a community-wide soil cleanup program because of
the extent and quantity of accumulated soil Pb. The post-Katrina benefits of
reducing soil Pb are expected to outweigh the foreseeable costs of Pb poisoning
to children returning to New Orleans. Notes: Environmental Science &
Technology
Reference Type: Journal Article Record Number:
41 Author: Mielke, H. W.; Dugas, D.; Mielke, P. W., Jr.; Smith, K. S.;
Gonzales, C. R. Title: Associations between soil lead and childhood
blood lead in urban New Orleans and rural Lafourche Parish of
Louisiana Pages: 950-4, 1997 Sep. Accession Number:
9300928 Abstract: This study evaluates associations between soil lead
concentrations (SPb), age of housing, and blood lead levels (BPb) of children in
metropolitan New Orleans and Lafourche Parish, Louisiana. The database includes
over 2,600 SPb and 6,000 BPb samples paired by their median values and pre-1940
housing percentages for 172 census tracts. Associations were evaluated with
Fisher's exact test and Spearman's rho test and modeled with the least sum of
absolute deviations regression. Census tracts with low SPb are associated with
new housing, but census tracts with high SPb are evenly split between old and
new housing [Fisher's exact test, p = 8.60 X 10(-13) for the percentage of
housing built before 1940 (percent pre-1940 housing) versus SPb]. The p-value
for SPb versus BPb is 12 orders of magnitude stronger than the p-value for
percent pre-1940 housing versus BPb. Census tracts with low BPb are associated
with new housing, but census tracts with high BPb are split evenly between old
and new housing (Fisher's exact test, p = 1. 67 X 10(-12) for percent pre-1940
housing versus BPb). Census tracts with high SPb are associated with high BPb
and census tracts with low SPb are associated with low BPb (Fisher's exact test,
p = 3.18 X 10(-24) for BPb versus SPb). The Spearman's rho test of the
association of SPb and BPb in Orleans and Lafourche Parishes yielded a p-value
of 6.12 X 10(-24). The least sum of absolute deviations regression model of the
data is BPb = 1. 845 + 0.7215 (SPb)0.4. A comparison of the modeled BPb versus
observed BPb has an r(2) of 0.552 and a p-value of 2.83 X 10(-23) that this
relation was due to chance. If blood lead in children is more closely associated
to soil lead than to the age of housing, then primary lead prevention should
also include soil lead. Notes: Environmental Health Perspectives.
105(9) Journal Article
Reference Type: Journal
Article Record Number: 24 Author: Mielke, H. W.; Gonzales,
C. R.; Smith, M. K.; Mielke, P. W. Title: The urban environment and
children's health: soils as an integrator of lead, zinc, and cadmium in New
Orleans, louisiana, U.S.A Pages: 117-29, 1999 Aug. Accession
Number: 10433843 Abstract: Soils are evaluated as a diagnostic
tool of environmental conditions that influence health. The samples for this
study are urban topsoil (0-2.5 cm depth) samples (n=4026) analyzed for Pb, Zn,
and Cd by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The
parent materials for New Orleans soils are derived from the Mississippi River,
and alluvium from the Bonnet Carre Spillway (n=31) serve as control samples for
this study. The urban samples were stratified by census tract (n=286). Blood Pb
(BL) levels of children </=6 years were also stratified by census tract and
paired with soil Pb (SL) (n=175). A significant association (P=1.2x10(-23)) was
found between median BL and median SL. The association was modeled by
BL=3.06+0.33 (SL)(0.5) (correlation coefficient=0.69 between the modeled BL and
the observed BL and P=3.5x10(-22)). A median SL threshold (>/=310 microgram
g(-1) and <310 microgram g(-1)) for higher metal census tracts (HMCTs) and
lower metal census tracts (LMCTs), respectively, represents median BL exposures
above and below 9 microgram dL(-1). HMCTs and LMCTs were characterized by
demographic and socioeconomic data. HMCTs are more likely (P=4. 5x10(-6))
inhabited by Blacks than by Whites. Of 13,803 children </=6 years in HMCTs,
75% are Black and 22% are White, with other making up the remaining 3%. In
LMCTs, the Black to White children ratio is 50:50. In HMCTs, socioeconomic
indicators for Blacks are depressed compared to Whites. Zn and Cd are
potentially phytotoxic in HMCTs. Children exhibit a steep rise in BL at SL
<100 microgram g(-1), and empirically, a safe SL for most children is around
80 microgram++ g(-1). SL is a useful diagnostic tool, and curtailing SL may
complement primary Pb prevention for children. Copyright 1999 Academic
Press. Notes: Environmental Research. 81(2) Journal
Article
Reference Type: Journal Article Record
Number: 35 Author: Mielke, H. W.; Reagan, P. L. Title:
Soil is an important pathway of human lead exposure Pages: 217-29,
1998 Feb. Accession Number: 9539015 Abstract: This review
shows the equal or greater importance of leaded gasoline-contaminated dust
compared to lead-based paint to the child lead problem, and that soil lead,
resulting from leaded gasoline and pulverized lead-based paint, is at least or
more important than lead-based paint (intact and not pulverized) as a pathway of
human lead exposure. Because lead-based paint is a high-dose source, the
biologically relevant dosage is similar to lead in soil. Both lead-based paint
and soil lead are associated with severe lead poisoning. Leaded gasoline and
lead in food, but not lead-based paint, are strongly associated with population
blood lead levels in both young children and adults. Soil lead and house dust,
but not lead-based paint, are associated with population blood lead levels in
children. Most soil lead and house dust are associated with leaded gasoline.
Lead-based paint dust is associated with cases of renovation of either exterior
or interior environments in which the paint was pulverized. Based upon the
limited data to date, abatement of soil lead is more effective than abatement of
lead-based paint in reducing blood lead levels of young children. About equal
numbers of children under 7 years of age are exposed to soil lead and lead-based
paint. Seasonality studies point to soil lead as the main source of population
blood lead levels. Soil lead is a greater risk factor than lead-based paint to
children engaged in hand-to-mouth and pica behavior. In summary, soil lead is
important for addressing the population of children at risk of lead poisoning.
When soil lead is acknowledged by regulators and the public health community as
an important pathway of human lead exposure, then more effective opportunities
for improving primary lead prevention can become a reality.
Reference Type:
Journal Article Record Number: 34 Author: Murgueytio, A. M.;
Evans, R. G.; Roberts, D. Title: Relationship between soil and dust
lead in a lead mining area and blood lead levels Pages: 173-86, 1998
Apr-Jun. Accession Number: 9577749 Abstract: The
relationship between lead mining waste and childhood lead poisoning is poorly
understood. This study evaluates the contribution of soil lead to blood lead
levels. METHODS: 125 children between 6 and 71 months of age living in a lead
mining area of southwestern Missouri were evaluated for blood lead and their
homes tested for lead in soil, dust, and paint. These results were compared to
26 control children. RESULTS: Homes in the lead mining area had significantly
increased soil and dust lead levels and significantly higher blood lead levels.
The primary source of dust lead was soil lead. There was a strong relationship
between blood lead levels and dust, soil, and paint lead. CONCLUSION: Soil lead
related to mining operations plays a significant role in contributing to blood
lead levels in children. Notes: Journal of Exposure Analysis and
Environmental Epidemiology. 8(2) Journal Article
Reference Type: Journal Article Record Number:
1 Author: Nielsen, J. B.; Kristiansen, J. Title: Remediation
of soil from lead-contaminated kindergartens reduces the amount of lead adhering
to children's hands Pages: 282-8, 2005 May. Accession
Number: 15316573 Abstract: Risk related to contaminated soil is
based on the oral intake of soil and dust among children. This exposure is a
consequence of mouthing behaviour, which exposes children to whatever adheres to
their hands or toys. This project compared hand exposure of children to lead
following outdoor playground activities before and after an intervention. The
intervention consisted of replacement of contaminated top soil from the most
intensively used playground areas and coverage of bare soil with wood chips or
grass. We included children from three kindergartens: one with very low levels
of lead in soil and two kindergartens with an average lead concentrations in
soil of 100-200 mg/kg. Measurements of lead in soil 5-7 weeks after
interventions in two kindergartens verified that the interventions had
effectively reduced the potential exposure to lead from the most intensively
used areas of the playgrounds. The average lead concentration in soil after
intervention was below 10 mg/kg. We found a good agreement between the average
concentration of lead in soil and the amount of lead on the hands of the
children. Thus, the exposure marker worked and had the advantage compared to a
blood sample, that we could evaluate the effect of the interventions shortly
after they were accomplished using a noninvasive method. The amount of lead on
the hands measured in one of the two kindergartens after the remediation (0.73
microg) was not significantly different from the control kindergarten (0.58
microg). Children from the second kindergarten still had higher median exposures
to lead (1.29 microg), but a large overlap existed with several children having
lower amounts of lead on their hands than some children from the control
kindergarten. Large variations in the amount of lead on hands were observed.
Variations may reflect true differences in concentrations of lead in soil, but
may also reflect different behavior and playing patterns. Our study
demonstrated, that it was possible in a cost-effective way to reduce exposure
significantly and to verify the effect with a sensitive, noninvasive method
shortly after the interventions had been implemented.. Notes: Journal
of Exposure Analysis and Environmental Epidemiology. 15(3) Evaluation
Studies Journal Article
Reference Type: Journal Article Record Number:
70 Author: O'Heany, J.; Kusiak, R.; Duncan, C. E.; Smith, J. F.;
Smith, L. F.; Spielberg, L. Title: Blood lead and associated risk
factors in Ontario children Pages: 477-83, 1988 Jun 1. Accession
Number: 3406713 Abstract: The purpose of this study was to
determine blood levels in Ontario children and to identify those risk factors
associated with higher blood lead levels. A random sample of 1315 children aged
7 and younger from urban, suburban and rural Ontario was selected. Blood lead
concentration was determined in finger prick blood samples by graphite furnace
atomic absorption spectrophotometry. Measurements of lead in air, tap water,
soil, and gasoline were also established. Traffic pattern were determined in
each area. A questionnaire was administered to a random sample of 800 families
of the children tested to assess the presence of other risk factors. Urban
children had higher geometric mean blood lead levels (12.02, S.D. = 4.4
micrograms/dl) than suburban children (9.95, S.D. = 3.5 micrograms/dl), and
they, in turn, had higher blood lead levels than rural children (8.91, S.D. =
3.9 micrograms/dl). Each of these differences is statistically significant (p
less than 0.001). Fifty four (4.3%) of all children were at or above the alert
level of 20 micrograms/dl. The proportion above the alert level did not differ
significantly between urban, suburban and rural children. Blood lead levels were
slightly higher for males than females and for pre-schoolers aged 3 and 4,
compared to school age children aged 5 and 6. The blood lead levels of these
children were significantly lower than that of children surveyed near a point
source of industrial emissions. Multivariate statistical modelling resulted in a
set of characteristics which best explained the differences in children's blood
lead levels.(ABSTRACT TRUNCATED AT 250 WORDS) Notes: Science of the
Total Environment. 71(3) Journal Article
<
Reference
Type: Journal Article Record Number: 31 Author: Pounds,
J. G.; Leggett, R. W. Title: The ICRP age-specific biokinetic model
for lead: validations, empirical comparisons, and explorations Pages:
1505-11, 1998 Dec. Accession Number: 9860909 Abstract: The
objective of this manuscript is to provide a description of the International
Commission for Radiation Protection (ICRP) model and a comparison to other
models (the integrated exposure uptake biokinetic [IEUBK] and O'Flaherty
models), including the software used with the models, and a comparison of the
model predictions for selected situations. The ICRP biokinetic model for Pb is a
multicompartmental model for Pb uptake and disposition in children and in
adults. The model describes deposition and retention of absorbed Pb in numerous
tissues, removal from tissues to plasma, and movement along various routes of
excretion. Long-term skeletal behavior of Pb is described in terms of
age-specific rates of restructuring of compact and trabecular bone. The ICRP
model is more flexible and has wider applicability than the IEUBK model. The
major disadvantages are that application of the computer model requires some
basic computer skills, and the user must convert the Pb concentrations in food,
air, soil, dust, paint, or other media to the amount of Pb ingested or inhaled
per day. Direct comparisons between the ICRP model and the IEUBK model are
provided by modeling blood Pb levels using the IEUBK v0.99d default Pb uptakes
and intake values. The model is used to simulate occupational exposure cases and
a controlled Pb inhalation experiment in adult humans. Finally, use of the model
to explore situations with limited data is illustrated by simulating the
kinetics and disposition of Pb during acute Pb poisoning and chelation therapy
in a child. [References: 29] Notes: Review Environmental Health
Perspectives. 106 Suppl 6 Journal Article Review, Tutorial
Author: Dennis J. Paustenbach; Brent L. Finley; Thomas F. Long.
Title: The Critical Role of House Dust in Understanding the Hazards Posed by Contaminated Soils Journal:
International Journal of Toxicology, Vol. 16, No. 4-5, 339-362 Abstract:
The health risks posed by soil pollutants are generally thought to be due to soilingestion and have often resulted in massive regulatory efforts to remedy such contamination. The contribution of this route to the actual human health hazard has been questioned, however, as soil removal alone seems to have little influence on the body burdens of soil contaminants in exposed individuals. Ongoing research also has repeatedly and substantially reduced the estimates of soilingested daily. Because comparatively little time is spent outdoors by most individuals, exposure to soil brought indoors, present as house dust, is now thought to be nearly as important as the directingestion of soil. Exposure via house dust has not been studied specifically, but several observations suggest that it may be important. Dust is largely composed of fine particles of tracked-in soil. The smaller dust particles cling to surfaces better than soil, and contaminant concentrations are often higher in house dust. Fine particles are likely to be more bioavailable, and degradation is slower indoors. Contaminants thus may be concentrated and more readily available in the areas most frequented. In some studies, contaminant levels in dust are correlated more closely with body burdens of contaminants than other sources, suggesting that this route should be considered when assessing risks from soil. Until more research addressing exposure to dust is conducted, recommendations for assessing potential health risks from this pathway are provided.
Reference Type: Journal Article Record Number:
62 Author: Prenney, B. Title: Community lead
exposure Pages: 191-5, 1993 Jan. Accession Number:
8422050 Abstract: In August, 1990, a regional transit authority began
removing paint on two overhead bridges on a commuter railroad line running
through a residential neighborhood of Lynn, Massachusetts, an industrial city
north of Boston. The contracted work involved the sandblasting of existing
bridge paint to prepare the surface for repainting. The sandblasting was
conducted without shrouding or adequate worker protection. The bridge paint was
not tested for lead content, nor were neighborhood residents informed of the
operations prior to the commencement of the work. Following complaints by
residents to the local and state health departments, a cease-work order was
issued. Laboratory tests of paint samples revealed a lead content ranging from
5% to 15%. Sandblasting debris was evident throughout the adjacent neighborhood.
What followed was a 3-month effort by state and local government officials and
the transit authority and its contractors to assess, communicate, and remedy the
damage done by the operations. Soil, dust, and blood samples were collected to
assess environmental contamination and health effects. Notices were sent,
meetings held, and informational sites established to inform community residents
of the impact of the operations and remediation efforts. The local and Boston
media provided extensive coverage of the incident and its aftermath. Remediation
efforts involved the relocation of occupants from residences in proximity of the
site and extensive clean-up of the interiors of affected homes by licensed lead
abatement contractors. The cost of the cleanup was well over $1
million.(ABSTRACT TRUNCATED AT 250 WORDS) Notes: American Journal of
Industrial Medicine. 23(1) Journal Article
Reference Type: Journal Article Record Number:
74 Author: Rabinowitz, M.; Leviton, A.; Needleman, H.; Bellinger, D.;
Waternaux, C. Title: Environmental correlates of infant blood lead
levels in Boston Pages: 96-107, 1985 Oct. Accession Number:
4076115 Abstract: From a blood lead survey of 11,837 births, 249
newborns were enrolled in a 2-year, longitudinal study. Their blood leads (PbB)
were measured semiannually, and their homes were visited for repeated
collections of dust, soil, indoor air, tap water, and paint. Recent refinishing
activity and the sizes of nearby streets were recorded. Overall mean PbB was 7.2
micrograms/dl (SD = 5.3) at birth. PbB did not vary systematically with age.
Each subject's average postnatal PbB correlated highly with the amount of lead
in dust (r = 0.4, P less than 0.0001) and soil (r = 0.3, P less than 0.001), and
with the lead in paint (r = 0.2, P less than 0.01). Dust, soil and air lead
levels correlated with one another. Refinishing activity in the presence of lead
paint was associated with elevations of PbB. Water lead, proximate traffic,
weight of recovered dust, race, maternal age and education, and sex were not
predictive of PbB. Multivariate models of PbB were constructed that become
increasingly predictive with age (r2 = 20 to 37%). Indoor dust lead, lead in
soil, refinishing activity, and season were the independent
variables. Notes: Environmental Research. 38(1) Journal
Article
Reference Type: Journal Article Record
Number: 69 Author: Rabinowitz, M. B.; Bellinger, D.
C. Title: Soil lead-blood lead relationship among Boston
children Pages: 791-7, 1988 Dec. Accession Number:
3233378 Notes: Bulletin of Environmental Contamination &
Toxicology. 41(6) Journal Article
Author:Reagan PL and
Silbergeld EK. (1989). Establishing a health based standard for lead in
residential soils. In: Hemphill and Cothern, eds. Trace substances in
environmental health, Supplement to Volume 12,(1990) of Environmental
Geochemistry and Health. Abstract:
Reference Type:
Journal Article Author:Ren HM, Wang JD, Wang GP, Zhang XL, Wang CM.
Ren HM, Wang JD, Wang GP, Zhang XL, Wang CM. Title:[Influence of soil
lead upon children blood lead in Shenyang City] Notes:Huan Jing Ke Xue.
2005 Nov;26(6):153-8. Abstract:The dynamic correlation coefficients
between soil lead and blood lead, the children blood lead arose from soil lead
and the length of time over which the blood lead concentration can fall to be at
or below the threshold value (10 microg x dL(-1)) are analyzed. If the
aggregated soil lead and blood lead are stratified by the seven geographic
regions studied, an elevated R of 0.9200 could be calculated, and the lead
exposure assessment may require knowledge of geographic dimension of the
exposure topology components. The children blood lead levels calculated based on
the soil lead in the unit of geographic region show that the blood lead levels
of about 90% of children exceed the threshold value in the west industrial area,
while they are all below the threshold value in the east area. The children,
whose blood lead level exceed the threshold value, are in the range of 3.48% -
31.81% in the other areas. The length of time over which the blood lead
concentration can fall to be at or below the threshold value is highest, and
average 26.68months, in the west area, and the order is the west > the north
> the northeast > the southwest > the northwest > central area >
the east, it is zero in the east area, and the maximum recovery time follow the
same order. The blood lead levels and the recovery time are controlled by the
environmental lead contamination, and the lead hazard intervention would
contribute to the fall of blood lead levels.
Reference Type:
Journal Article Record Number: 9 Author: Rubin, C. H.;
Esteban, E.; Reissman, D. B.; Daley, W. R.; Noonan, G. P.; Karpati, A.;
Gurvitch, E.; Kuzmin, S. V.; Privalova, L. I.; Zukov, A.; Zlepko,
A. Title: Lead poisoning among young children in Russia: concurrent
evaluation of childhood lead exposure in Ekaterinburg, Krasnouralsk, and
Volgograd.[see comment] Pages: 559-62, 2002 Jun. Accession
Number: 12055045 Abstract: The Gore-Chernomyrdin Commission
encouraged a binational collaboration to evaluate pediatric lead poisoning in
Russia. The study evaluated children in three Russian cities: Krasnouralsk, a
small city with minimal traffic centered around a copper smelter; and
Ekaterinburg and Volgograd, both of which are large cities with multiple
factories and heavy vehicular traffic. This project was the first international
use of portable blood lead analysis instruments. In each city, at least 90% of
children attending selected neighborhood kindergartens participated. We selected
kindergartens on the basis of their proximity to industrial areas and major
traffic corridors. We obtained capillary blood samples and analyzed for lead
content and hemoglobin (Hgb) levels in the field, and collected environmental
samples (i.e., indoor dust, tap water, play area soil, and interior and exterior
paint) and analyzed for each participating school and in the homes of about 10%
of the children who had elevated blood lead levels (BLLs; greater than or equal
to 10 microg/dL). We calculated all age-, sex-, and city-specific geometric
means using generalized estimating equations to account for covariance within
kindergartens, and used multivariate logistic regression models to identify
variables predictive of elevated BLLs. Overall, 23% of study children had
elevated BLLs and 2% were anemic, defined as Hgb < 11 g/dL. Krasnouralsk had
the highest geometric mean BLL (10.7 microg/dL), the highest percentage of
children (60%) with elevated BLLs, and the highest percentage of anemic children
(4%). All soil samples in Krasnouralsk had detectable lead levels. Volgograd was
the only city that had paint samples with elevated lead levels. We found
apparent city-specific differences in the percentages of children with elevated
BLLs. Lead-contaminated soil and dust, which can result from lead-based
automotive fuel and from lead-related industrial emissions, appear to be the
most important routes of lead exposure of those evaluated in this study.
Elevated lead levels found in paint samples from Volgograd may indicate old
undercoats of lead-based paint that could represent a regionally rather than
nationally important source of exposure. Notes: Environmental Health
Perspectives. 110(6) Journal Article
Reference Type:
Journal Article Record Number: 85 Author: Schmitt, N.;
Philion, J. J.; Larsen, A. A.; Harnadek, M.; Lynch, A. J. Title:
Surface soil as a potential source of lead exposure for young
children Pages: 1474-8, 1979 Dec 8. Accession Number:
519574 Abstract: Soil analyses revealed an elevated lead content in
the surface soil of three British Columbia cities. The lead accumulations were
largely attributed to dustfall from a nearby large lead-zinc smelter in Trail
and to automotive traffic in Nelson and Vancouver. Although the mean
concentrations of lead in the soil were relatively low at Nelson (192 parts per
million [ppm]), in selected areas of Vancouver with heavy traffic they were
similar to those found within 1.6 km of the large smelter at Trail (1545 and
1662 ppm respectively). In a study conducted in 1975, children aged 1 to 6 years
in Trail and Nelson were found to have higher mean blood lead levels than grade
nine students. The findings of the later study support the view that particulate
lead in surface soil and dust accounted for most of the greater lead absorption
in the younger children. Notes: Canadian Medical Association Journal.
121(11) Journal Article
Reference Type: Journal
Article Record Number: 68 Author: Sedman, R.
M. Title: The development of applied action levels for soil contact: a
scenario for the exposure of humans to soil in a residential
setting Pages: 291-313, 1989 Feb. Accession Number:
2651104 Abstract: The California Site Mitigation Decision Tree Manual,
1985, was developed by the California Department of Health Services to provide a
detailed technical basis for managing uncontrolled hazardous waste sites. The
Decision Tree describes a process that relies on criteria, Applied Action Levels
(AALs) to evaluate and, if necessary, mitigate the impact of uncontrolled
hazardous waste sites on the public health and the environment. AALs are
developed for individual substances, species, and media of exposure. AALs have
been routinely developed for the media of air and water; however, an approach
for developing AALs for soil contact was lacking. Given that the air pathway for
soil contact is addressed in AALs for air, two routes of exposure, ingestion and
dermal contact, are addressed in developing AALs for soil contact. The approach
assumes a lifetime of exposure to soil in a residential setting. Age-related
changes in exposure are included in the scenario. Exposure to soil due to
ingestion and dermal contact are quantitated independently and then integrated
in the final exposure scenario. A mass balance approach using four elements is
employed to quantitate soil ingestion for a young child. Changes in soil
ingestion with age are based on age-related changes in blood lead concentration
and mouthing behavior. Dermal exposure to soil was determined from studies that
reported skin soil load and from estimates of exposed skin surface area.
Age-related changes in the dermal exposure to soil are also based on changes
with age of blood lead concentration and mouthing behavior. The estimates of
exposure to soil due to ingestion and dermal contact are integrated, and an
approach for developing AALs is advanced. AALs are derived by allocating the
Maximum Exposure Level as described in the Decision Tree to the average daily
exposure to soil. Toxicokinetic considerations for the two routes of exposure
must be included in deriving AALs for the soil medium of exposure. [References:
71] Notes: Review Environmental Health Perspectives. 79 Journal
Article Review, Tutorial
Reference Type: Journal Article Record Number:
7 Author: Sheldrake, S.; Stifelman, M. Title: A case study
of lead contamination cleanup effectiveness at Bunker Hill Journal:
Science of the Total Environment. Volume: 2003 Issue:
303(1-2). Pages: 105-23. Accession Number:
12568767 Abstract: A review of cleanup effectiveness at Bunker Hill
Superfund Site (BHSS) has shown that yard soil cleanup is an effective tool for
reducing house dust lead concentrations, thereby reducing children's blood lead
levels. This review has also shown that contiguous cleanup of residences has a
three-fold greater reduction of children's blood lead levels compared with
cleaning only those homes where children currently reside by reducing exposures
attributable to neighboring properties. This review underscores the importance
of a community-wide, preventative approach to controlling lead contamination in
soil and house dust. This review has further characterized the need for careful
design, implementation, and perpetual maintenance of a community-wide lead
cleanup. Several key areas of importance to maintain large scale mining/smelting
remedies in the Bunker Hill area were analyzed and noted for further action,
including: infrastructure, institutional controls for homeowner projects (post
cleanup), erosion control for undeveloped hillsides with potential to impact the
developed valley floor, drainage improvements and flood control, waste piles,
and increasing the rate at which cleanup proceeds. Focusing on these areas is
crucial to minimizing recontamination at a large scale lead
cleanup. Notes: Journal Article
Reference Type: Journal Article Record Number:
82 Author: Shellshear, I. D.; Jordan, L. D.; Hogan, D. J.; Shannon, F.
T. Title: Environmental lead exposure in Christchurch children: soil
lead a potential hazard Pages: 382-6, 1975 Apr 23. Accession
Number: 1057086 Abstract: A study of childhood blood lead levels
and of soil lead levels has been carried out in Christchurch. The results
indicate a potent hazard especially to the child with unusual appetite for soil.
Screening and preventative programmes are briefly discussed. Notes:
New Zealand Medical Journal. 81(538) Journal Article
Reference
Type: Journal Article Record Number: 77 Author: Stark,
A. D.; Quah, R. F.; Meigs, J. W.; DeLouise, E. R. Title: The
relationship of environmental lead to blood-lead levels in
children Pages: 372-83, 1982 Apr. Accession Number:
7084166 Notes: Environmental Research. 27(2) Journal
Article Abstract:An in-depth study of the distribution of lead sources
in the residential environment of 377 children in New Haven, Connecticut, was
carried out. Substantial amounts of lead were present in soil, paint, and house
dust throughout New Haven, but not in air or water. Multiple regression modeling
indicated that the most important contributors to variation in children's
blood-lead levels were soil lead and exterior house paint lead. Using the best
five-variable model only 11.7% of the variation in the children's blood-lead
levels could be explained. This led to the conclusion that availability of lead
in the residential environment did not account for most of the variation
observed in the population.
Reference Type: Journal
Article Record Number: 57 Author: Stern, A.
H. Title: Derivation of a target level of lead in soil at residential
sites corresponding to a de minimis contribution to blood lead
concentration Pages: 1049-56, 1994 Dec. Accession Number:
7846312 Abstract: Inability to define either a clear toxicologic
threshold or a stochastic all-or-nothing (cancer-type) response model for the
noncarcinogenic effects of lead (Pb) in young children has posed difficulties
for derivation of risk-based target levels of Pb in residential soil. Approaches
based on empirical relationships between Pb levels in blood (PbB) and Pb in soil
suffer from inability to specify the numerous variables which mediate between
these two quantities. Approaches based on achieving a toxicologically de minimis
target PbB level (e.g., 10 micrograms/dl) are subject to large uncertainty in
estimating the distribution of existing PbB levels in a specific exposed
population and in estimating the relative contribution from nonsoil sources of
Pb. The multisource contribution to the distribution of PbB makes this approach
unsuited for determination of a target Pb level in a single medium. An
alternative approach is presented based on achieving a de minimis contribution
to PbB (delta PbB) from soil. Contributions to Pb exposure from outdoor soil and
indoor soil-derived dust (ISDD) are modeled and appropriate values are suggested
for input parameters. This analysis predicts that chronic exposure of young
children to 200 micrograms Pb/g (ppm) in residential soil will result in a delta
PbB of 2 micrograms Pb/dl blood. This concentration of Pb in soil may provide an
appropriate target level for residential soil when other significant sources of
Pb exposure are present. In other cases, this approach can be used to predict a
soil concentration of Pb corresponding to an appropriate non-de minimis delta
PbB. Notes: Risk Analysis. 14(6)
Author:Richard M. Sedman
Title:
The Development of Applied Action Levels
for Soil Contact: A Scenario for the
Exposure of Humans to Soil in a
Residential Setting.
Journal: Environmental Health Perspectives
Vol. 79, pp. 291-313, 1989.
CONTAINS EXCELLENT REVIEW OF SOIL LEAD BLOOD LEAD STUDIES PRIOR TO 1989.
Reference Type: Journal Article Record
Number: 28 Author: Succop, P.; Bornschein, R.; Brown, K.; Tseng,
C. Y. Title: An empirical comparison of lead exposure pathway
models Pages: 1577-83, 1998 Dec. Accession Number:
9860917 Abstract: Structural equation modeling is a statistical method
for partitioning the variance in a set of interrelated multivariate outcomes
into that which is due to direct, indirect, and covariate (exogenous) effects.
Despite this model's flexibility to handle different experimental designs,
postulation of a causal chain among the endogenous variables and the points of
influence of the covariates is required. This has motivated the researchers at
the University of Cincinnati Department of Environmental Health to be guided by
a theoretical model for movement of lead from distal sources (exterior soil or
dust and paint lead) to proximal sources (interior dust lead) and then finally
to biologic outcomes (handwipe and blood lead). The question of whether a single
structural equation model built from proximity arguments can be applied to
diverse populations observed in different communities with varying lead amounts,
sources, and bioavailabilities is addressed in this article. This reanalysis
involved data from 1855 children less than 72 months of age enrolled in 11
studies performed over approximately 15 years. Data from children residing near
former ore-processing sites were included in this reanalysis. A single model
adequately fit the data from these 11 studies; however, the model needs to be
flexible to include pathways that are not frequently observed. As expected, the
more proximal sources of interior dust lead and handwipe lead were the most
important predictors of blood lead; soil lead often had a number of indirect
influences. A limited number of covariates were also isolated as usually
affecting the endogenous lead variables. The blood lead levels surveyed at the
ore-processing sites were comparable to and actually somewhat lower than those
reported in the the Third National Health and Nutrition Examination Survey.
Lessened bioavailability of the lead at certain of these sites is a probable
reason for this finding. Notes: Environmental Health Perspectives. 106
Suppl 6 Clinical Trial Journal Article
Author:Texas
Department of Health. 2004. Health Consultation. Analysis of Risk Factors for
Childhood Blood Lead Results. El Paso, Texas.
http://www.dshs.state.tx.us/epitox/consults/elppasblpbgisfinal4_23.pdf Summary:
Using large database from El Paso Area, study found an odds ratio 4.5 (1.4,
14.2)for the relationship between a 500 ppm increase in soil lead and blood lead
level > 10 ug/dlBR>
Author: Mark P Taylor, Carolyn A Schniering, Bruce P Lanphear and Alison L Jones. Title: Lessons learned on lead poisoning in children: One-hundred years
on from Turner's declaration
Abstract: There is significant emerging evidence showing life-long negative health, intellectual and socio-behavioural impacts as a result of
childhood blood lead concentrations well below the widely used intervention level of 10 mg/dL. This issue raises serious health concerns for
children in several Australian smelting and mining towns. Routine educational and home cleanliness advice to wet mop floors rather than to use
a brush and pan to reduce lead exposure risks have been shown to have limited efficacy. This paper argues, as advocated 100 years ago by
Queensland doctor Alfred Jefferis Turner, that childhood lead poisoning can only be mitigated via primary prevention and reduction of contaminants
at source. Given that the effects of lead exposure are irreversible, there is a strong argument for the application of the precautionary
principle to dealing with childhood lead exposure. There is a clear need to improve regulatory controls and emissions management to reduce
environmental lead exposure risks.Notes Journal of Paediatrics and Child Health. 2010. doi:10.1111/j.1440-1754.2010.01777.x
Reference Type: Journal
Article Record Number: 66 Author: Thornton, I.; Davies, D.
J.; Watt, J. M.; Quinn, M. J. Title: Lead exposure in young children
from dust and soil in the United Kingdom Pages: 55-60, 1990
Nov. Accession Number: 2088756 Abstract: A survey of metals
in United Kingdom dusts and soils has confirmed widespread lead contamination
with a geometric mean value for lead in surface (0-5 cm) garden soils of 266
micrograms/g and in housedusts of 561 micrograms/g (excluding old mining areas).
A subsequent detailed survey of 97 householders in Birmingham with 2-year-old
children showed dust lead loading in the home environment to be an important
predictor of blood lead concentrations in young children, when both variables
fell within the normal range for the U.K. The total estimated lead uptake by the
young child was 36 micrograms/day of which 1 microgram was by inhalation and 35
micrograms by ingestion. Notes: Environmental Health Perspectives.
89 Journal Article
Reference Type: Journal
Article Record Number: 20 Author: Tristan, E.; Demetriades,
A.; Ramsey, M. H.; Rosenbaum, M. S.; Stavrakis, P.; Thornton, I.; Vassiliades,
E.; Vergou, K. Title: Spatially resolved hazard and exposure
assessments: an example of lead in soil at Lavrion, Greece Pages:
33-45, 2000 Jan. Accession Number: 10677144 Abstract:
Spatially resolved hazard assessment (SRHA) and spatially resolved exposure
assessment (SREA) are methodologies that have been devised for assessing child
exposure to soil containing environmental pollutants. These are based on either
a quantitative or a semiquantitative approach. The feasibility of the
methodologies has been demonstrated in a study assessing child exposure to Pb
accessible in soil at the town of Lavrion in Greece. Using a quantitative
approach, both measured and kriged concentrations of Pb in soil are compared
with an "established" statutory threshold value. The probabilistic approach
gives a refined classification of the contaminated land, since it takes into
consideration the uncertainty in both the actual measurement and estimated
kriged values. Two exposure assessment models (i.e., IEUBK and HESP) are used as
the basis of the quantitative SREA methodologies. The significant correlation
between the blood-Pb predictions, using the IEUBK model, and measured
concentrations provides a partial validation of the method, because it allows
for the uncertainty in the measurements and the lack of some site-specific
measurements. The semiquantitative applications of SRHA and SREA incorporate
both qualitative information (e.g., land use and dustiness of waste) and
quantitative information (e.g., distance from wastes and distance from
industry). The significant correlation between the results of these assessments
and the measured blood-Pb levels confirms the robust nature of this approach.
Successful application of these methodologies could reduce the cost of the
assessment and allow areas to be prioritized for further investigation,
remediation, or risk management. Notes: Environmental Research.
82(1) Journal Article
Author:Clarice Umbelino de Freitasa, , , Eduardo Mello De Capitanib,
Nelson Gouveiac, Marcia Helena Simonettid, Mario Ramos de Paula e Silvae, Alice
Momoyo Sakumaf, Maria de Fatima Henriques Carvalhof, Maria Cristina Duranf,
Paulo Tigleaf and Maria Helena de Abreue Title:Lead exposure in an
urban community: Investigation of risk factors and assessment of the impact of
lead abatement measures Abstract:Introduction A battery recycling
plant located in an urbanized area contaminated the environment with lead
oxides. The Secretary of Environment of the State of Sao Paulo demanded an
evaluation of lead exposure among the population in the vicinity of the plant.
Objectives To assess the lead exposure of children, to propose control
measures and evaluate the impact of these measures.
Methods Cross-sectional study of all children<13 years old in a radius
of 1 km from the plant responsible for the contamination. Blood lead levels
(BLL) were determined for each child and questionnaires were applied to their
parents. Mean BLL were compared before and after control measures were
implemented. Logistic regression identified risk factors of lead exposure.
Results Of the 850 investigated children, 311 presented BLL above the
action limit established by the World Health Organization. Overall, the median
BLL was 7.3 μg/dL and it varied according to age of children (higher among 1-5
years old) and distance of the residence from the plant. Risk factors identified
for BLL>10 μg/dL were: to live in unpaved areas, parent working in the plant,
distance from the plant, to play on the ground, pica, and to drink locally
produced milk. After control measures were implemented (closing the plant, soil
removal, dust vacuum-cleaning in the households, etc.), a reduction of 46% in
BLL was observed considering the 241 re-evaluated children with levels >10
μg/dL. Conclusions This study showed that combined abatement measures
were effective in reducing BLL in children living close to a contaminating
source. These results informed the decision-making process regarding management
of contaminated areas in Brazil. Notes: Environmental Research.
doi:10.1016/j.envres.2006.09.004 Author:U.S. EPA Title:Seasonal Rhythms of BLL Levels: Boston,
1979-1983: Final Report. Abstract:Several researchers have observed
increased incidence of lead poisoning during summer months. Reasons for seasonal
rhythms in blood-lead levels, if such a phenomenon is real, are not immediately
apparent. Altered human physiology and higher levels of lead exposure during the
summer months have both been postulated as reasons for the temporal variations.
This study was undertaken to examine temporal variation in blood- and
environmental-lead levels in data observed for a sample of 249 children in
Boston between 1979 and 1983 at the Brigham and Women's Hospital. The two
primary objectives of this study were to: Determine the extent to which
blood-lead levels recorded in the study conducted at the Brigham and Women's
Hospital exhibit seasonal variation. Determine if any existing seasonal trends
in blood-lead levels are correlated with seasonal trends in environmental
levels. For each child in the study, blood-lead and environmental-lead
measurements were collected longitudinally over a period of two years. Levels of
lead in air, dust, water, and soil were included in the environmental data.
Nominally, between two and five measurements were taken for each response (blood
or environmental lead) in six month increments. For the investigation of
seasonal trends in the blood and environmental measures, each response was
analyzed separately. For statistical reasons, responses were log transformed
before analysis. In addition to seasonal variations, the child's date of birth,
and age were considered for possible effects. Because significant correlations
were observed between the repeated measures taken on individual children, these
correlations were estimated and incorporated into the model estimates. In
determining whether seasonal components of variation existed for each response,
the first step was to model monthly averages and determine whether they
exhibited systematic monthly variation. Although this approach reflected a
significant source of variation, the interpretation is cumbersome. Therefore,
because many of the media sampled exhibited higher levels in the summer and
lower levels in the winter, a sinusoidal (Fourier) model was investigated for
the seasonal component with parameters to represent the magnitude as well as the
phase, or month of the peak level. This approach was sufficient for modeling
lead levels in the environmental media. However, for blood, where the maximum
and the minimum did not occur six months apart, a slightly more complicated
Fourier model was required. Blood-lead levels were found to have highly
significant seasonal variations (p<0.0001), with the maximum modeled to occur
in late June, and the minimum in March. The estimated maximum- to-minimum ratio
was 2.5. Without adjusting for other effects, observed geometric mean blood-lead
levels by month of year ranged from 2.1 ug/dl in February to 7.5 ug/dl in July.
Age of child was also found to be a significant factor; the square root of age
was found to be more linearly related to blood-lead levels than was age itself.
Consistent with other studies, blood-lead levels in children were found to
increase with age. Air-, floor dust-, furniture dust-, and window sill dust-lead
levels all exhibited highly significant seasonal variation. The estimated
maximum-to-minimum ratios were 2.3 for air lead, 1.5 for floor dust lead, 1.4
for furniture dust lead, and 1.6 for window sill dust lead. Modeled lead levels
for air, floor dust, and furniture dust all had peaks in July. Oddly, peak
window sill dust-lead levels were modeled to occur in November. Each of these
responses were also significantly related to the date of measurement, with a
decrease observed over time. This is not unexpected due to the concurrent
reduction in the use of leaded gasoline. The extent to which levels of lead in
blood were correlated with levels of lead in the environment was also evaluated.
As stated above, the seasonal component of variation in blood-lead levels was
highly statistically significant. However, after adjusting for the linear
effects of environmental measures, the (residual) blood-lead levels did not
exhibit even marginally significant seasonal variation (at the 10 percent
level). These results do not necessarily imply a causal relationship between
seasonal variation in environmental-lead levels and seasonal rhythms in
blood-lead levels. The fact that there were arguably parallel rhythms in blood-
and, say, floor- dust lead levels, doesn't imply that the blood-lead levels are
influenced by the floor-dust lead levels. In particular, if the floor dust-lead
levels were to be multiplied by two, while retaining the same blood lead levels,
and models were refit, the same statistical significance levels would be
reported by this analysis approach. Thus, it would be important to develop a
physiological model relating levels of lead in the environment to those in
blood, before proclaiming a causal relationship. Nonetheless in this data, which
was collected in the early 1980's from a specific set of children in Boston,
there was abundant evidence supporting the existence and parallelism of the
seasonal variations among blood-, air-, floor dust, and furniture dust-lead
levels. The three environmental-lead measures peak in July which is very near
the blood-lead peak month of June. In addition, the maximum-to-minimum ratios in
the environmental-lead measures, ranging from 1.4 to 2.3, are of the same order
of magnitude as the blood-lead ratio of 2.5. Thus, based on the results of this
study, it is quite plausible that seasonal variations in environmental-lead
levels contribute to the blood-lead rhythms. Notes:1995. EPA
747-R-94-003. Washington, DC
Reference Type: Journal Article Record Number:
10 Author: von Braun, M. C.; von Lindern, I. H.; Khristoforova, N. K.;
Kachur, A. H.; Yelpatyevsky, P. V.; Elpatyevskaya, V. P.; Spalinger, S.
M. Title: Environmental lead contamination in the Rudnaya
Pristan--Dalnegorsk mining and smelter district, Russian far
East Pages: 164-73, 2002 Mar. Accession Number:
12051794 Abstract: A preliminary survey of a remote mining and
smelting region of the Russian Far East (RFE) indicates significant soil lead
contamination and a high probability of childhood lead poisoning. Lead
concentrations in residential gardens (476-4310 mg/kg, Gmean=1626 mg/kg) and in
roadside soils (2020-22900 mg/kg, Gmean=4420 mg/kg) exceed USEPA guidance for
remediation. Preliminary biokinetic estimates of mean blood levels suggest that
preschool children are at significant risk of lead poisoning from soil/dust
ingestion with levels predicted to average 13-27 microg/dl. Samples of other
pathways, such as air, water, paint, interior dust, and garden produce, and
pediatric and occupational blood lead levels are needed. An assessment of the
industry's ability to improve emissions controls and materials handling should
also be undertaken. Global lessons in remediating contamination problems and
preventing childhood lead poisoning must be applied in innovative ways to meet
the logistical, social, and economic challenges in the RFE. (c) 2002 Elsevier
Science (USA). Notes: Environmental Research. 88(3) Journal
Article
Title:
The influence of soil remediation on lead in house dust
Authors:
VON LINDERN Ian H. (1) ; SPALINGER Susan M. (1) ; BERO Bridget N. (2) ; PETROSYAN Varduhi (3) ; VON BRAUN Margrit C. (4) ;
Abstract:
Lead in house dust has long been recognized as a principal source of excess lead absorption among children at the Bunker Hill Superfund Site (BHSS) in northern Idaho. House dust lead concentration from homeowner's vacuum cleaner bags has been monitored since the epidemic of childhood lead poisoning in 1974. Geometric mean house dust lead concentrations decreased from > 10 000 mg/kg in 1974 to approximately 4000 mg/kg in 1975, in response to air pollution control initiatives at the defective primary lead smelter. After smelter closure, 1983 mean dust lead concentrations were near 3000 mg/kg and were most dependent on soil sources. Following emergency soil removals from public areas and roadsides and fugitive dust control efforts in the mid-1980s, house dust lead decreased by approximately 40-60% to 1200-1500 mg/kg. In 1992, a cleanup goal of 500 mg/kg dust lead community average, with no individual home exceeding 1000 mg/kg, was adopted. This goal was to be achieved by a combination of contaminated soil removals and fugitive dust control efforts throughout the 21 square mile BHSS. Continual reductions in house dust lead concentrations have been noted throughout the residential area soil cleanup. Geometric mean house dust lead concentrations averaged approximately 500-600 mg/kg from 1996 to 1999 and dropped below 500 mg/kg in 2000. Analysis of these data indicates that approximately 20% of the variance in dust lead concentrations is attributed to yard, neighborhood, and community soil lead concentrations. Since 1996, dust lead concentrations and dust and lead loading rates have also been measured by dust mats placed at entryways into the homes. Neighborhood soil lead concentrations, household hygiene, the number of adults living in the home, and the number of hours a child spends outdoors in summer explain approximately 26% of the variance in mat dust lead loading rates. It is estimated that post-remedial house dust lead concentrations will stabilize at 400-500 mg/kg, as compared to approximately 200 mg/kg in socio-economically similar background communities; the difference possibly attributed to residual soil concentrations (3-6 times background), recontamination of rights-of-way, tracking of non-residential mining district soils and dusts, fugitive dusts associated with the remediation, and residual structural or carpet dusts.. Notes: The Science of The Total Environment
Volume 303, Issues 1-2, 15 February 2003, Pages 59-78
Reference Type: Journal Article Record Number:
6 Author: von Lindern, I.; Spalinger, S.; Petroysan, V.; von Braun,
M. Title: Assessing remedial effectiveness through the blood
lead:soil/dust lead relationship at the Bunker Hill Superfund Site in the Silver
Valley of Idaho Pages: 139-70, 2003 Feb 15. Accession
Number: 12568769 Abstract: The 21 square mile Bunker Hill
Superfund Site in northern Idaho includes several thousand acres of contaminated
hillsides and floodplain, a 365-acre abandoned lead/zinc smelter and is home to
more than 7000 people in 5 residential communities. Childhood lead poisoning was
epidemic in the 1970s with >75% of children exceeding 40 microg/dl blood
lead. Health response activities have been ongoing for three decades. In 1991, a
blood lead goal of 95% of children with levels less than 10 microg/dl was
adopted. The cleanup strategy, based on biokinetic pathways models, was to
reduce house dust lead exposure through elimination of soil-borne sources. An
interim health intervention program, that included monitoring blood lead and
exposures levels, was instituted to reduce exposures through parental education
during the cleanup. In 1989 and 2001, 56% and 3% of children, respectively,
exceeded the blood lead criteria. More than 4000 paired blood lead/environmental
exposure observations were collected during this period. Several analyses of
these data were accomplished. Slope factors derived for the relationship between
blood lead, soil and dust concentrations are age-dependent and similar to
literature reported values. Repeat measures analysis assessing year to year
changes found that the remediation effort (without intervention) had
approximately a 7.5 microg/dl effect in reducing a 2-year-old child's mean blood
lead level over the course of the last ten years. Those receiving intervention
had an additional 2-15 microg/dl decrease. Structural equations models indicate
that from 40 to 50% of the blood lead absorbed from soils and dusts is through
house dust with approximately 30% directly from community-wide soils and 30%
from the home yard and immediate neighborhood. Both mean blood lead levels and
percent of children to exceed 10 microg/dl have paralleled soil/dust lead intake
rates estimated from the pathways model. Application of the IEUBK model for lead
indicates that recommended USEPA default parameters overestimate mean blood lead
levels, although the magnitude of over-prediction is diminished in recent years.
Application of the site-specific model, using the soil and dust partitions
suggested in the pathways model and an effective bioavailability of 18%,
accurately predicts mean blood lead levels and percent of children to exceed 10
microg/dl throughout the 11-year cleanup period. This reduced response rate
application of the IEUBK is consistent with the analysis used to originally
develop the cleanup criteria and indicates the blood lead goal will be
achieved. Notes: Science of the Total Environment. 303(1-2) Journal
Article
Author:von Lindern IH, Spalinger SM, Bero BN, Petrosyan V, von
Braun MC. Title:The influence of soil remediation on lead in house
dust. Abstract:Lead in house dust has long been recognized as a
principal source of excess lead absorption among children at the Bunker Hill
Superfund Site (BHSS) in northern Idaho. House dust lead concentration from
homeowner's vacuum cleaner bags has been monitored since the epidemic of
childhood lead poisoning in 1974. Geometric mean house dust lead concentrations
decreased from >10000 mg/kg in 1974 to approximately 4000 mg/kg in 1975, in
response to air pollution control initiatives at the defective primary lead
smelter. After smelter closure, 1983 mean dust lead concentrations were near
3000 mg/kg and were most dependent on soil sources. Following emergency soil
removals from public areas and roadsides and fugitive dust control efforts in
the mid-1980s, house dust lead decreased by approximately 40-60% to 1200-1500
mg/kg. In 1992, a cleanup goal of 500 mg/kg dust lead community average, with no
individual home exceeding 1000 mg/kg, was adopted. This goal was to be achieved
by a combination of contaminated soil removals and fugitive dust control efforts
throughout the 21 square mile BHSS. Continual reductions in house dust lead
concentrations have been noted throughout the residential area soil cleanup.
Geometric mean house dust lead concentrations averaged approximately 500-600
mg/kg from 1996 to 1999 and dropped below 500 mg/kg in 2000. Analysis of these
data indicates that approximately 20% of the variance in dust lead
concentrations is attributed to yard, neighborhood, and community soil lead
concentrations. Since 1996, dust lead concentrations and dust and lead loading
rates have also been measured by dust mats placed at entryways into the homes.
Neighborhood soil lead concentrations, household hygiene, the number of adults
living in the home, and the number of hours a child spends outdoors in summer
explain approximately 26% of the variance in mat dust lead loading rates. It is
estimated that post-remedial house dust lead concentrations will stabilize at
400-500 mg/kg, as compared to approximately 200 mg/kg in socio-economically
similar background communities; the difference possibly attributed to residual
soil concentrations (3-6 times background), recontamination of rights-of-way,
tracking of non-residential mining district soils and dusts, fugitive dusts
associated with the remediation, and residual structural or carpet
dusts. Notes:Sci Total Environ. 2003 Feb 15;303(1-2):59-78.
Author:Wang C, Ouyang H, Wang J, Liu J, Zhang X, Wang Y. 2003.
Impact of lead pollution in environment on children's health in Shenyang City]
2003. Huan Jing Ke Xue. Sep;24(5):17-22. Abstract: In this thesis,
based on field sampling and indoor integrated analysis with GIS technology, the
impact of lead pollution in the atmosphere, dust, soil on the children was
explored systemically. Results showed that, Lead exposure in environment was
widely distributed and Lead pollution was serious in Shenyang city. The spatial
variations of Lead, with four high content centers in the soil, dust and
atmosphere, were distinct in all the environmental media. Moreover, there were
daily, seasonal and annual variations in the atmosphere. The impact of lead
pollution in environment on children health was serious in Shenyang city. The
blood lead content of the children (ZPP > 2.3 mumol/L) with the age of 0-10
ranged from 10.98 to 511.2 micrograms/L, and the average of 135.59 micrograms/L.
The blood content of 40% children was beyond the normal standard. And
correlative degree of lead contents between in blood and in atmosphere was
highest, secondly in soil, and last in dust. With the implication of non-lead
gasoline the lead content in the atmosphere had declined greatly. Along with the
flying dust, the lead in the soil and dust was likely to entering into the
atmosphere to bring out potential pollution risk.
AuthorsWeitzman M, Aschengrau A, Bellinger D, Jones R, Hamlin JS, Beiser
A TitleLead-contaminated soil abatement and urban children's blood
lead levels. AbstractOBJECTIVE--To test the hypothesis that a
reduction of 1000 ppm or more of lead in soil accessible to children would
result in a decrease of at least 0.14 mumol/L (3 micrograms/dL) in blood lead
levels. SETTING--Urban neighborhoods with a high incidence of childhood lead
poisoning and high soil lead levels. DESIGN--Randomized controlled trial of the
effects of lead-contaminated soil abatement on blood lead levels of children
followed up for approximately 1 year after the intervention. PATIENTS--A total
of 152 children less than 4 years of age with venous blood lead levels of 0.34
to 1.16 mumol/L (7 to 24 micrograms/dL). Children were largely poor and had a
mean age at baseline of 32 months, a mean blood lead level of 0.60 mumol/L (12.5
micrograms/dL), and a median surface soil lead level of 2075 ppm.
INTERVENTIONS--Children were randomized to one of three groups: the study group,
whose homes received soil and interior dust abatement and loose paint removal;
comparison group A, whose homes received interior dust abatement and loose paint
removal; and comparison group B, whose homes received only interior loose paint
removal. MAIN OUTCOME MEASURES--Change in children's blood lead levels from
preabatement levels to levels approximately 6 and 11 months after abatement.
RESULTS--The mean decline in blood lead level between preabatement and 11 months
after abatement was 0.12 mumol/L (2.44 micrograms/dL) in the study group (P =
.001), 0.04 mumol/L (0.91 microgram/dL) in group A (P = .04), and 0.02 mumol/L
(0.52 microgram/mL) in group B (P = .31). The mean blood lead level of the study
group declined 0.07 mumol/L (1.53 micrograms/dL) more than that of group A (95%
confidence interval [CI], -0.14 to -0.01 mumol/L [-2.87 to -0.19 micrograms/dL])
and 0.09 mumol/L (1.92 micrograms/dL) more than group B (95% CI, -0.16 to -0.03
mumol/L [-3.28 to -0.56 micrograms/dL]). When adjusted for preabatement lead
level, the 11-month mean blood lead level was 0.06 mumol/L (1.28 micrograms/dL)
lower in the study group as compared with group A (P = .02) and 0.07 mumol/L
(1.49 micrograms/dL) lower than in group B (P = .01). The magnitude of the
decline independently associated with soil abatement ranged from 0.04 to 0.08
mumol/L (0.8 to 1.6 micrograms/dL) when the impact of potential confounders,
such as water, dust, and paint lead levels, children's mouthing behaviors, and
other characteristics, was controlled for. CONCLUSIONS--These results
demonstrate that lead-contaminated soil contributes to the lead burden of urban
children and that abatement of lead-contaminated soil around homes results in a
modest decline in blood lead levels. The magnitude of reduction in blood lead
level observed, however, suggests that lead-contaminated soil abatement is not
likely to be a useful clinical intervention for the majority of urban children
in the United States with low-level lead exposure. SourceJAMA. 1993
Apr 7;269(13):1647-54.
AuthorsWillmore A, Sladden T, Bates L, Dalton
CB. TitleUse of a geographic information system to track
smelter-related lead exposures in children: North Lake Macquarie, Australia,
1991-2002. AbstractTo determine patterns of childhood lead exposure in
a community living near a lead and zinc smelter in North Lake Macquarie,
Australia between 1991 and 2002. METHODS: An analysis of serial blood lead
levels (BLL) of children less than 13 years of age in North Lake Macquarie
participating in voluntary blood lead screening. Distance to the smelter and
soil lead concentration of the child's place of residence was calculated.
Categorical analysis of BLL by residential distance from smelter, residential
soil lead concentration, age and year of sample was calculated. Linear
regression models were fit for blood lead levels against residential distance
from smelter, the log of residential soil lead concentration, age and year of
BLL sample. RESULTS: Geometric mean BLLs were statistically significantly higher
for distances less than 1.5 kilometres from the smelter and for residential soil
lead concentrations greater than 300 ppm. Yearly BLLs since 1995 were
statistically significantly lower than for preceding years, with an average
decrease of 0.575 microgram/dL per year since 1991. BLLs are statistically
significantly higher for children whose age is 1 to 3 years old. Linear
regression modelling of BLL predicted a statistically significant decrease in
BLL of 3.0831 microgram/dL per kilometre from the smelter and a statistically
significant increase in BLL of 0.25 microgram/dL per log of lead in residential
soil. The model explained 28.2% of the variation in BLL. CONCLUSIONS:
Residential distance to the smelter, log of residential soil lead concentration,
child's age and year of BLL sample are statistically significant factors for
predicting elevated BLLs in children living near a North Lake Macquarie lead
smelter. SourceInt J Health Geogr. 2006 Jul
19;5(1):30
Reference Type: Journal Article Record
Number: 72 Author: Wilson, D.; Esterman, A.; Lewis, M.; Roder, D.;
Calder, I. Title: Children's blood lead levels in the lead smelting
town of Port Pirie, South Australia Pages: 245-50, 1986
Jul-Aug. Accession Number: 3767433 Abstract: This survey
included 1,239 children, representing 50% of the elementary school population of
the lead smelting town of Port Pirie. Of these children, 7% had a capillary
blood lead level equal to or greater than 30 micrograms/dl, which is the
Australian National Health and Medical Research Council's "level of concern."
There was a statistically significant difference in capillary lead levels by
area of residence that was independent of age, sex, soil lead, rainwater tank
lead, and school attended. A case-control study indicated that the following
subset of factors was most predictive of an elevated blood lead level: household
members who worked with lead in their occupations; living in a house with
flaking paint on the outside walls; biting finger nails; eating lunch at home on
school days; when at school, appearing to have relatively dirty clothing; when
at school, appearing to have relatively dirty hands; and living on a household
block with a large area of exposed dirt. A program to reduce the risk of
elevated blood lead levels in Port Pirie children has been
introduced. Notes: Archives of Environmental Health.
41(4)
Author:Jonathan Wilson, Tim Pivetz, Peter Ashley, David
Jacobs, Warren Strauss, John Menkedick, Sherry Dixon, Hsing-Chuan Tsai, Vincent
Brown, Warren Friedman, Warren Galke and Scott Clark Title:Evaluation
of HUD-funded lead hazard control treatments at 6 years
post-intervention Excerpt: Exterior entry dust-lead and soil lead
concentration at 6 years post-intervention were found to be significant
determinants of interior floor dust lead levels, indicating the contribution of
exterior lead sources to interior floor dust-lead loadings.....The finding that
lead in exterior dust and soil were significant determinants of interior floor
dust-lead loadings at 6 years post-clearance supports the findings of Clark et
al. (2004) who conducted pathway analysis on the post-intervention exterior dust
and soil lead samples from the Evaluation data and reported a direct pathway
from exterior entry dust lead loading to floor, interior entry, and windowsill
dust lead loading and an influence of soil treatments on the exterior entry dust
lead loading. The findings also support the need to address exterior lead
hazards as part of routine lead hazard control activities. Notes:
Environmental Research 2006 (in press)
Reference Type: Journal
Article Record Number: 76 Author: Yaffe, Y.; Flessel, C. P.;
Wesolowski, J. J.; del Rosario, A.; Guirguis, G. N.; Matias, V.; Gramlich, J.
W.; Kelly, W. R.; Degarmo, T. E.; Coleman, G. C. Title: Identification
of lead sources in California children using the stable isotope ratio
technique Pages: 237-45, 1983 Jul-Aug. Accession Number:
6615005 Abstract: Two case studies are presented which apply the lead
isotope ratio method to the identification of lead sources in 12 Oakland,
California children. One study examined lead sources in 10 children, ages 3 to
15 yr, living together as an extended family in dilapidated housing close to a
busy freeway. Eight children had elevated blood lead levels (greater than or
equal to 30 micrograms/dl) and 6 children also had elevated erythrocyte
protoporphyrin levels (greater than or equal to 50 micrograms/dl). A second case
study examined 2-yr-old male twins, both with elevated blood lead and
erythrocyte protoporphyrin levels, living in a modest, but well maintained inner
city duplex apartment. Paint and surface soil samples collected in and around
both households had high lead concentrations. Paint concentrations ranged from
2.9 to 273 mg/g and surface soil concentrations from 0.48 to 7.1 mg/g. The
isotopic ratios of lead in the blood of these children were close to the average
lead ratios of paints from exterior walls and to the lead ratios of surface
soils in adjacent areas where the children played. In both case studies, the
data suggest that the lead in the soil was derived mainly from weathering of
lead-based exterior paints and that the lead-contaminated soil was a proximate
source of lead in the blood of the children. Notes: Archives of
Environmental Health. 38(4) Journal Article
Reference Type:
Journal Article Record Number: 88 Author: Yaffe, Y.;
Flessel, C. P.; Wesolowski, J. J.; del Rosario, A.; Guirguis, G. N.; Matias, V.;
Gramlich, J. W.; Kelly, W. R.; Degarmo, T. E.; Coleman, G. C. Title:
Identification of lead sources in California children using the stable isotope
ratio technique Pages: 237-45, 1983 Jul-Aug. Accession
Number: 6615005 Abstract: Two case studies are presented which
apply the lead isotope ratio method to the identification of lead sources in 12
Oakland, California children. One study examined lead sources in 10 children,
ages 3 to 15 yr, living together as an extended family in dilapidated housing
close to a busy freeway. Eight children had elevated blood lead levels (greater
than or equal to 30 micrograms/dl) and 6 children also had elevated erythrocyte
protoporphyrin levels (greater than or equal to 50 micrograms/dl). A second case
study examined 2-yr-old male twins, both with elevated blood lead and
erythrocyte protoporphyrin levels, living in a modest, but well maintained inner
city duplex apartment. Paint and surface soil samples collected in and around
both households had high lead concentrations. Paint concentrations ranged from
2.9 to 273 mg/g and surface soil concentrations from 0.48 to 7.1 mg/g. The
isotopic ratios of lead in the blood of these children were close to the average
lead ratios of paints from exterior walls and to the lead ratios of surface
soils in adjacent areas where the children played. In both case studies, the
data suggest that the lead in the soil was derived mainly from weathering of
lead-based exterior paints and that the lead-contaminated soil was a proximate
source of lead in the blood of the children. Notes: Archives of
Environmental Health. 38(4) Journal Article
Reference Type:
Journal Article Record Number: 21 Author: Yiin, L. M.;
Rhoads, G. G.; Lioy, P. J. Title: Seasonal influences on childhood
lead exposure Pages: 177-82, 2000 Feb. Accession Number:
10656860 Abstract: We conducted a study to examine seasonal changes in
residential dust lead content and its relationship to blood lead in preschool
children. We collected blood and dust samples (floors, windowsills, and carpets)
to assess lead exposure. The geometric mean blood lead concentrations are 10.77
and 7.66 microg/dL for the defined hot and cold periods, respectively (p <
0.05). Lead loading (milligrams per square meter) is the measure derived from
floor and windowsill wipe samples that is most correlated with blood lead
concentration, whereas lead concentration (micrograms per gram) is the best
variable derived from carpet vacuum samples. The variation of dust lead levels
for these three dust variables (floor lead loading, windowsill lead loading, and
carpet lead concentration) are consistent with the variation of blood lead
levels, showing the highest levels in the hottest months of the year, June,
July, and August. The regression analysis, including the three representative
dust variables in the equations to predict blood lead concentration, suggests
that the seasonality of blood lead levels in children is related to the seasonal
distributions of dust lead in the home. In addition, the outdoor activity
patterns indicate that children are likely to contact high leaded street dust or
soil during longer outdoor play periods in summer. Consequently, our results
show that children appear to receive the highest dust lead exposure indoors and
outdoors during the summer, when they have the highest blood lead levels. We
conclude that at least some of the seasonal variation in blood lead levels in
children is probably due to increased exposure to lead in dust and
soil. Notes: Environmental Health Perspectives. 108(2) Journal
Article
Author: Xintaras, Charles. 1992. Impact of
Lead-Contaminated Soil on Public Health Abstract: U.S. Department of
Health and Human Services, Public Health Service, Centers for Disease Control,
Agency for Toxic Substances and Disease Registry, Charles Xintaras,
Sc.D. This report provides background information on the complex and
interactive factors that environmental health scientists need to consider when
evaluating the impact of lead-contaminated soil on public health. A definitive
analysis of the impact on public health of lead-contaminated soil is limited
often by a lack of information on human exposure factors and soil conditions.
Each waste site, therefore, poses a unique challenge to the health assessor and
each site should be assessed in terms of its own characteristics. The
development of action levels for lead in soil lies outside the scope of the
present report. However, the health assessor will find the information in this
report useful in characterizing the significance of exposure pathways and the
importance of the physical and chemical properties of the lead compounds that
may impact on persons' uptake of lead. The correlation between lead-contaminated
soil and blood lead (PbB) level continues to challenge investigators.
Correlations cited in the literature are influenced in specific studies by many
factors, including access to soil, behavior patterns (especially of children),
presence of ground cover, seasonal variation of exposure conditions, particle
size and composition of the lead compounds found at various sites and the
exposure pathway. These complex factors explain in some instances discrepant
findings that are reported in the literature. The reader is cautioned that much
research is ongoing to clarify relationships between lead in soil and the amount
absorbed by humans. Therefore, the associations and mathematical relationships
between soil lead concentrations and blood-lead levels cited in this paper
should be understood as being what has been published in the scientific
literature, but subject to change as newer information becomes available.
Author: Sammy Zahran�, Howard W. Mielke, Christopher R. Gonzales, Eric T. Powell and Stephan Weiler.
Title: New Orleans before and after Hurricanes Katrina/Rita: A Quasi-Experiment of the Association between Soil Lead and Children�s Blood Lead
Notes: Environ. Sci. Technol., DOI: 10.1021/es100572s
Abstract:Prior to Hurricanes Katrina and Rita (HKR), significant associations were noted between soil lead (SL) and blood lead (BL) in New Orleans. Engineering failure of New Orleans levees and canal walls after HKR set the stage for a quasi-experiment to evaluate BL responses by 13306 children to reductions in SL. High density soil surveying conducted in 46 census tracts before HKR was repeated after the flood. Paired t test results show that SL decreased from 328.54 to 203.33 mg/kg post-HKR (t = 3.296, p ≤ 0.01). Decreases in SL are associated with declines in children�s BL response (r = 0.308, p ≤ 0.05). When SL decreased at least 1%, median children�s BL declined 1.55 μg/dL. Declines in median BL are largest in census tracts with ≥50% decrease in SL. Also individual BL in children was predicted as a function of SL, adjusting for age, year of observation, and depth of flood waters. At the individual scale, BL decreased significantly in post-HKR as a function of SL, with BL decreases ranging from b = −1.20 to −1.65 μg/dL, depending on the decline of SL and whether children were born in the post-HKR period. Our results support policy to improve soil conditions for children.
Lead is nefarious element - it is used in bombs and bullets in wars, bullets in crime and poisons hundreds of millions of children and adults worldwide through soil lead and lead paint exposure. Lead also poisons very large numbers of wildlife due to the current and past use of lead shot and bullets.
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