Indianapolis, Indiana (USA)
Points represent blood lead poisoning cases (>10 ug/dl) between 1992 and
1994
Based upon a sample of only 8% of children
Link
to Source
Chicago, Illinois
Link to Source
Link to Soil
Lead Contour Maps of Various Cities
Toxicity Below 10 ug/dl - Cognitive
Canfield, R.L., Henderson, C.R., Cory-Slechta, D.A., Cox, C., Jusko, T.A., & Lanphear, B.P. Intellectual impairment in children with blood lead concentrations below 10 g/dL: The Rochester cohort study. The New England Journal of Medicine 348(16):1517-1526.
Chiodo LM, Covington C, Sokol RJ, Hannigan JH, Jannise J, Ager J, Greenwald M, Delaney-Black V. 2007. Blood lead levels and specific attention effects in young children. Neurotoxicol Teratol.
Schnaas L, Rothenberg SJ, Flores MF, Martinez S, Hernandez C, Osorio E, Velasco SR, Perroni E. Reduced intellectual development in children with prenatal lead exposure. Environ Health Perspect. 2006 May;114(5):791-7.
Surkan PJ, Zhang A, Trachtenberg F, Daniel DB, McKinlay S, Bellinger DC. Neurotoxicology. Neuropsychological function in children with blood lead levels <10mug/dL. 2007 Jul 25.
Miranda ML, Kim D, Galeano MA, Paul CJ, Hull AP, Morgan SP. 2007. The relationship between early childhood blood lead levels and performance on end-of-grade tests. Environ Health Perspect. 2007 Aug;115(8):1242-7.
|
Toxicity Below 10 ug/dl - Mortality
Menke A, Muntner P, Batuman V, Silbergeld EK, Guallar E. Bloodlead below 0.48 mmol/L (10 mg/dL) and mortality among US
adults. Circulation 2006;114:1388–94.
|
Potential Solution?
In order to promote evidenced based decision making, it is suggested that very LARGE (1 km square?)community trials be conducted that measure seasonal atmospheric lead loading following three treatments in urban soil contaminated areas - soil covering, irrigation and control.
Irrigation would have the added benefit of reducing exposure to particulates such as PM2.5 and PM10 and other contaminants that covary with Pb in urban soils such as benzoapyrene, Cu, Zn, Cd, Cr Ni and Hg; however, it is unclear whether irrigation would be cost-effective when compared to soil covering.
The costs associated with soil covering would include the purchase of soil, soil transport costs, sod/grass seeding, lawn maintenance (mowing/watering) during re-growth, and continued maintenance. The cost associated with irrigation would include installation, future water costs (which could be extracted from ubiquitous municipal water mains) and irrigation system maintenance.
It must be noted that LARGE scale community trials have never been conducted (small scale test results have been equivocal, likely due to resuspension and deposition from the neighborhood and surrounding properties).
Preliminary Discussion
Generally, five study designs
have been used to test the hypothesis of an association between soil lead and
blood lead: ecological- temporal, ecological-spatial, cross-sectional,
prospective soil removal, and descriptive. Each of the study designs has
limitations.
Cross-Sectional
The cross-sectional study
design is the most frequently applied study design. This study design is
severely limited due to exposure misclassification and outcome
misclassification. It is well known that in urban areas, soil lead
concentrations decay exponentially away from the roadside. It is also known that
soil lead concentrations are elevated adjacent to homes due to the effect of
past aerosols coming into contact with the side of buildings and dropping to the
soil below. In addition, in homes with exterior lead paint, the soils adjacent
to homes can become contaminated due to deterioration of leaded paint.
Cross-sectional studies that are based on single sample exposure will result in
exposure classification because point samples can be highly variable for the
above-mentioned reasons. Outcome misclassification arises due to the well-known
blood lead seasonality effect. Blood lead seasonality of groups of children has
shown that blood lead concentrations can increase over 100% between winter and
summer. The exposure and outcome misclassification makes it very difficult to
correlate due to the high variability of exposure (soil lead) and outcome (blood
lead). This likely explains the reason why cross-sectional studies sometime have
historically low correlations, and this is due to the inadequacy of the study
design. An example of a cross-sectional study was a study of the association
between soil lead and blood lead at four superfund sites which was completed by
the Agency for Toxic Substances and Disease Registry's (1999). This study found
that 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.
Ecological- Spatial
The ecological spatial study design
is completed by taking the average blood lead of a small area for a given period
of time, and correlating that blood lead with the average soil lead
concentration for the same small unit, across all the small area units in a
city. This study design has been successfully applied (R2 >0.65) in Syracuse
(Johnson and Bretsch, 2002), New Orleans (Mielke et al. 1997), and Shenyang (Ren
HM et al. 2005). This study design appears to be successful because the exposure
(soil lead) is generally an average of a large number of soil samples in a small
area, thus dampening out the exposure misclassification that occurs in the
cross-sectional study design. Furthermore, since it is time invariant, the
misclassification from seasonality effect that is found in the cross-sectional
study design is not a factor. The limitations of this study design is that the
confounding variable, homes with paint lead, are not accounted for. However,
this variable can be adjusted for. In fact, Mielke found that the p value for
spatial association between soil lead and blood lead was many orders of
magnitude lower than the association between the percentage of home with paint
lead with blood lead (Mielke et al., 1997). Another limitation is that in the
ecological study design, the association is between the average blood lead of
the group and not the individuals – thus the inference of a blood lead soil lead
association at the individual level should be made cautiously
Ecological – Temporal
The ecological temporal study
design is conducted by selecting a city, then taking the average monthly blood
lead concentration of all the children, for a specific time period, then
regressing against soil moisture and climate variables (Laid law et al. 2005).
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 (Laid law et al. 2005).
This approach is believed to be successful because it is thought that soil
moisture and climate variables are proxy indicators of urban lead contaminated
soil re-suspension (Laidlaw and Filipelli, 2006). This approach eliminates
spatial concerns, such as confounding by paint lead, and examines temporal
fluctuations only. The limitation of the study design is that it does not
account for variation in lead particles released from the opening and closing of
windows. However, it is not believed that the opening and shutting of windows is
related to temporal changes variables such as PM10 and soil moisture, thus it is
believed that lead particles released from the opening and closing of windows is
not related to a significant proportion of the variation in children’s blood
lead seasonality. In addition, ecological studies are based upon the group,
rather than the individual, and inferences at the individual level must be made
with caution.
Prospective Soil Removal
Prospective soil
removal studies remove lead contaminated soil from yards of selected homes while
leaving lead contaminated soil in yards of other homes. Blood lead
concentrations of children in the homes are then compared between treatment and
controls. These study designs have limitations. First, the sample sizes can be
very low. Second, the blood lead samples must be collected at the same point in
time to prevent outcome misclassification due to blood lead seasonality which
could result in lower correlations and p values. Some of these studies have
failed to account for differences in how the homes are sealed as well. These
studies can also fail because they do not take into account the fact that dust
that travels to a home does not originate from the soil from the home but the
surrounding community (von Linden et al., 2003). This was illustrated by
Sheldrake, S.; Stifelman, M. (2003) at the Near the Bunker Hill Superfund site
where they found that 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 approach has been successfully completed by Maisonet et al. who
conducted a pair-matched, case-control study of yard soil remediation and found
that yard soil removal was a strong protective factor for elevated blood lead
levels in children (odds ratio, 0.28; confidence interval,
0.08-0.92).
Descriptive
Isotopic studies hold promise,
however, in the United States some people suggest that there is an overlap in
isotope ratios of lead in paint and gasoline, which limits any source
apportionment. However the use of isotopic ratios have shown promise in Armenia
(Kurkjian & Flegal, 2003).
Abstracts
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.
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: 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 µg/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 µg/ft2), followed in descending order by Staten Island (452
µg/ft2), the Bronx (382 µg/ft2), Queens (198 µg/ft2) and finally, Manhattan (175
µg/ft2). When compared to the HUD/EPA indoor lead in dust standard of 40 µg/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, Jesús I.
Téllez-Hernándeza, Rocío Torres-Nerioa, Arturo Torresa, Lilia E. Batresa,
Ana-Cristina Cubillasb and Fernando Díaz-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 µg g–1.
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]
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.,
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 µg 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.
Link
to Paper
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: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
µg/dL (n=49) measured in this initial survey, appears to be much lower than
recently proposed by the Armenian Ministry of Nature
Protection.
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)
Link to
Paper
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)
Link to Manuscript
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 µg/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
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 Carré 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 Carré 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. [References:
92]
Notes: Review
Environmental Health Perspectives. 106 Suppl
1
Journal Article
Review, Tutorial
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. 
