Association Between Soil Lead and Blood Lead - Evidence


Mark Laidlaw, PhD


Email: markas1968@gmail.com

Link to my publications


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New York Times Article - 1925

In 1925, The New York Times Published the following words of Dr. Yandell Henderson, Professor of Applied Physiology at Yale University: “…the breathing day by day of fine lead dust from automobiles using leaded gasoline will produce chronic lead poisoning on a large scale in the population of cities…” and would cause “… vast number of the population to suffer from slow lead poisoning…”. He stated that “…This is probably the greatest single question in the field of public health that has ever faced the American public…”. Furthermore, he stated that “…It is the question whether scientific experts are to be consulted, and the action of the Government guided by their advice; or whether, on the contrary, commercial interests are to be allowed to subordinate every other consideration to that of profit".


To read the entire story, see the original article in the New York Times (1925)



Caltech Professor Clair Patterson stated the following in 1980: “Sometime in the near future it probably will be shown that the older urban areas of the United States have been rendered more or less uninhabitable by the millions of tons of poisonous industrial Pb residues that have accumulated in cities during the past century………Extrapolating from present information, …probably… it will be shown in the future that average American adults experience a variety of significant physiological and intellectual dysfunctions caused by long-term chronic lead insult to their bodies and minds which results from excess exposures to industrial lead that are five hundred-fold above natural levels of lead exposure, and that such dysfunctions on this massive scale may have significantly influenced the course of American history.” (NRC, 1980; see p. 265-349). This pivotal and controversial statement of Clair Patterson’s provided inspiration for this website.


The three main sources of lead exposure in urban environments are:

1) Soil (from leaded gasoline, exterior lead paint and lead smelters);
2) House Dust (from lead in soil and interior paint particles);
3) Water (from lead water lines)


This website focuses mainly on soil lead and does not thoroughly discuss the lead paint and water sources.

The lead emitted from gasoline (see line in blue) in high traffic inner city areas between the 1920's and 1980's (in the US) was deposited and incorporated within the top 5-10 centimetres of the surrounding soils. We now know that the lead in these soils can become resuspended into the air where it migrates into homes. People and pets also track the lead contaminated soil into homes. Children and adults are then poisoned. This, and in certain cases exposure to flaking lead paint and lead from lead water pipes, has resulted in epidemics of lead poisoning in large parts of some inner-city areas. This is a global phenomenon and will continue until lead in soil dust in urban areas is isolated.


Source - Laidlaw and Filippelli (2008)


To read the REAL history of Lead in Gasoline, read The Ethyl Controversy by Professor William Kovarik.


Lead emitted from gasoline (petrol) in high traffic Australian inner city areas between the 1930's and 2002.

Source - Louise Jane Kristensen (2015)


Historical emissions of lead into the atmosphere from past use of lead in gasoline (petrol) between 1950 and 1982 in 90 urban areas of the United States (Mielke et al., 2011)

Source - Mielke, Laidlaw and Gonzales (2010)


An example of the lead poisoning epidemic - Detroit, Michigan


Note that the cases in this picture likely only represent a portion of the the total number of cases as typically blood lead is drawn from less than the full population.


View Lead Poisoning Percentages in Each Detroit School

Early Childhood Lead Exposure and Academic Achievement:Evidence From Detroit Public Schools, 2008–2010 (Zhang et al, 2013)



Plot of Soil Lead Versus Children's Blood Lead in Detroit - Bickell 2010

This chart shows that when soil lead concentrations increase, children's blood lead levels increase.

Source - Bickell (2010)


In many urban inner-city areas of the United States, there is an epidemic of childhood blood lead poisoning (Gould, 2009). It has been estimated that 24.5%, or 9.6 million U.S. children have a blood lead in the range of 2 to 10 micrograms per decilitre, a level which will cause sub-clinical signs (Gould, 2009). The National Health and Nutrition Examination Survey (NHANES) III 1999-2002 database indicates that approximately 2.4 million children have blood Pb levels between 5 and 9.9 microgram/deciliter (Iqbal et al., 2008) and that within that population of 1-'5-year olds with blood Pb levels of 5 microgram/deciliter or higher, the prevalence was 47% for non-Hispanic Black children, 28% for Mexican American children, and 19% for non-Hispanic White children (Bernard and McGeehin, 2003). The fact that children of color are nearly 4 times more likely than white children to have blood Pb levels between 5 and 10 microgram/deciliter (and 13 times more likely to have blood Pb levels above 20 microgram/deciliter) (Bernard and McGeehin, 2003) raises concerns about social justice and the long-term health of these children. In addition, in 2004, in 10 ABLES states, a total of 10,527 females aged 16--44 years were tested, and all BLLs for this group were reported. Of the number tested, 1,370 (13.0%) had BLLs >5 µg/dL (10.9 per 100,000 female residents aged 16--44 years). I have not located the breakdown by race or by urban versus suburban area yet.


Why it is Important to Understand Exposure to Lead in Soil Dust


Childhood lead poisoning (Zahran et al., 2013a), (Zahran et al., 2013b) and preeclampsia/eclampsia (Zahran et al., 2014) have been shown to be associated with lead in soil and dust.


1) Childhood lead poisoning is one of the most common pediatric health problems in the United States today (CDC, 2014); Source
2) “Preeclampsia ... is the leading cause of maternal death worldwide and a major cause of preterm delivery”.... "Predicting preeclampsia is a major step towards saving the lives of many women”.Source
3) Lead is associated with autism Link to Review Paper

Low PbB levels (<10 ug/dL) typically associated with urban soil Pb exposure are associated with a myriad of health outcomes. Low PbB levels (<10 ug/dL) are associated with Attention-Deficit Hyperactivity Disorder (ADHD)(Nigg et al., 2010), a reduction in children’s tests scores for reading (odds ratio = 0.51, p = 0.006) (Chandramouli et al., 2009), writing (odds ratio = 0.49, p = 0.003) (Chandramouli et al., 2009; Miranda et al., 2007) and mathematics (Miranda et al., 2007). Canfield et al. (2003) observed that when lifetime average PbB concentrations in children increased from 1 to 10 mg/dL, the intelligence quotient (IQ) declined by 7.4 points. Jusko et al. (2008) observed that compared with children who had lifetime average PbB concentrations < 5 mg/ dL, children with lifetime average concentrations between 5 and 9.9 mg/dL scored 4.9 points lower on Full-Scale IQ (91.3 vs. 86.4, p = 0.03). Similarly, Surkan et al. (2007) observed that children with 5-10 mg/dL had 5.0 (S.D. 2.3) points lower IQ scores compared to children with PbB levels of 1-2 mg/dL (p = 0.03). Interestingly, multiple studies have shown that that the strongest Pb effects on IQ occurred within the the first few micrograms of PbB (Schnaas et al., 2006; Canfield et al., 2003; Lanphear et al., 2005). Low PbB levels (<10 ug/dL) have also been associated with various physiological outcomes such as kidney damage (Fadrowski et al., 2010), dental caries (Moss et al., 1999), puberty delay in boys (Williams et al., 2010) and girls (Selevan et al., 2003) and cardiovascular outcomes in adults (Navas-Acien et al., 2007).

Link to United States National Toxicology Program Monograph on Health Effects of Low-level Lead (June 2012)

For a recent review of the health effects of lead exposure, see Bellinger, 2011. Another good article to read is titled Epigenetics of early-life lead exposure and effects on brain development by Senut et al. (2012).

Eclampsia is a life-threatening complication of pregnancy, is a condition that causes a pregnant woman, usually previously diagnosed with preeclampsia (high blood pressure and protein in the urine), to develop seizures or coma. Women with preeclampsia are predisposed to convulsions, abruption placentae, disseminated intravascular coagulation, cerebral hemorhage, pulmonary edema, renal failure, liver haemorrhage and have an increased risk of developing hypertension and stroke later in life. The risks to foetuses include severe growth retardation, hypoxemia, acidosis, premature birth and death.


Link to a very recent review of the association between lead and preeclampsia/eclampsia/hypertension


Google Scholar Search Results For "Lead Poisoning" and Multiple Diseases:



Typical Pattern of Roadside Lead in Soil Found In Urban Cities

syracuse.jpg

Robin Raftis of IUPUI actually completed the work for this transect.

Source(Filippelli et al., 2005)- 3.5mb

Typical Pattern of Houseside Lead in Soil Found In Homes With Old Exterior lead Based Paint in Boston, Massachusetts



Yardside Lead in Soil (Boston)

Journal of Urban Technology, 9(2) (2002) 1466-1853


Urban Soil Lead Comes from Two Main Sources


1. Emissions from Past Use of Lead in Gasoline
2. Exterior Lead Paint


(note - lead smelters can be main sources when present as well)

schematic.jpg


Schematic of Typical Pattern of Urban Soil Lead Concentration

Link to Source


Discussion of Association between Soil Lead and Blood Lead



The Emerging Paradigm About The Cause of Urban Lead Poisoning


The emerging lead poisoning paradigm is that chronic urban lead poisoning is caused by exposure to lead contaminated soil (contaminated from past leaded gasoline emissions and exterior lead paint) that is tracked into the interior of homes by shoes(Hunt et al., 2006)and the feet and fur of family pets and exterior urban soil that is re-suspended into the atmosphere where it penetrates interiors of homes and settles on interior contact surfaces(Layton and Beamer, 2009)(Laidlaw and Filippelli, 2008). Children are also exposed to lead via direct ingestion of soil outdoors. Chronic urban lead poisoning can also be caused by exposure to interior lead paint dust particles during renovation of older homes and flaking of interior lead paint dust particles and lead leaching into tap water from old lead pipes. Sometimes, children are exposed to lead originating from BOTH lead paint particles AND from exterior lead contaminated soil dust. Children are primarily exposed via hand to mouth activity (thumb sucking). Acute lead poisoning is probably caused by ingestion of interior and exterior lead paint that has chipped or via ingestion of a large dose of soil with high lead concentrations.


See also, Filippelli and Laidlaw, 2010



Relationship Between Exterior Soil Lead and Interior House Dust Lead Concentrations - Sydney, Australia



Link to Source

Peer Reviewed Evidence That Exterior Soil Is The Primary Source of Interior Lead Loading and Lead Concentration in House Dust

2014 French Study

2014 Sydney Australia Study






Several Major Pathways of Pb Exposure



Safe Yards: Improving Urban Health through Lead-Safe Yards (Litt et al., 2002)

Boston - Bivariate correlations among environmental measures and childs blood lead


Source - Rabinowitz et al

Study of lead in house dust, interior and exterior paint and soil in 575 homes in Los Angele and Sacramento, California (Sutton et al., 1995)


In a study of 575 homes in Sacramento, California (USA) Sutton et al. (1995) stated the following: “Continuous variables measured in this survey expected to influence lead levels in house dust include age of housing, lead levels in interior and exterior paint and soil and paint deterioration. Spearman correlation coefficients for lead dust concentration levels and age of housing, interior paint, exterior paint and soil were -0.34, 0.19, 0.29 and 0.35, respectively (p < 0.01 for each). These variables had little ability to explain dust lead loading levels measured. Spearman correlation coefficients for dust lead loading and age of housing, lead levels in interior paint, and soil were -0.20, 0.12, 0.15, and 0.18, respectively (p <0.02). Among these four variables, interior paint lead levels had the weakest association with lead levels measured in dust (ppm or micrograms per meter squared). Interior paint condition was not associated with dust lead levels. There was a statistically significant but small relationship between exterior paint condition and lead dust concentration levels in Sacramento (Spearmen correlation coefficient r = 0.16, p = 0.03) and dust lead loading in Los Angeles (Spearmen correlation coefficient r = 0.015, p = 0.02). Households in Los Angeles reporting interior paint changes in the past year had geometric mean dust lead loading levels twice as high as in households not reporting paint changes ( 47 micrograms per meter squared compared to 23 micrograms per meters squared). No correlation between lead concentration and interior paint changes was demonstrated in either of the two communities tested.”


Migration Pathways of Contaminated Soil and Airborne Particulates to Indoor Dust



Source - Layton and Beamer

In cases of chronic exposure lead often sequesters in the highest concentrations first in the bones/teeth, then in the kidneys.


Lead Concentrations In Bones/teeth Increase With Age



Link to Source

Priest and Frank (1990) reviewed the literature regarding lead in bones and teeth.  Priest and Frank (1990) indicated that modern skeletal levels have been claimed to be 1000 times greater those determined in ancient Peruvian skeletons. The levels of lead in bones has been observed to be highest in inner city residents compared to suburban and rural residents. In addition, a linear increase in the logarithm of the bone lead concentration was found with age (r=0.9). At ages 3 to 4, the mean bone lead concentration for urban specimens was 5.55 ppm 4.05 ppm for suburban, and for rural as little as 1.9 ppm, whereas at ages 9 to 10, the means were 13.1, 10 and 6.3 respectively. Teeth in urban children contained five times as much lead as those of rural children. Another study showed urban tooth lead levels twice as high as suburban levels. These findings have been observed internationally. Thus it has been shown that children efficiently absorb lead which is stored in their bones.(Source - Priest, Nicholas D. , and  Van de Vyver Frank. 1990. Trace Metals and Fluoride in Bones and Teeth. CRC Press, 400 p).


Lead Stored in Women's Bones Is Episodically Released During Pregnancy Exposing Fetus and Mother to Lead


Google Scholar Search of topic

A Large Portion of House Dust Is Composed of Soil

Investigator % House Dust From Soil
Hawley (1985)
80
Thornton et al. (1985)
20
Camann and Harding (1989)
50
Fergusson and Kim (1991)
30-50
Calabrese and Stanek (1992)
20-78

Source - Estimates of the relative contribution of exterior soil to house dust (Paustenbach et al, 1997).

Based upon the table above, it should be easily understood that if the exterior soils are contaminated with Pb, the interior house dust will be contaminated with Pb as well.

This figure suggests that the simple act of residents removing their shoes before entering their homes can have a major impact on the soil lead concentrations inside homes. Another of the many lines of evidence that lead in soil contributes to indoor lead exposure.


http://www.ricocolorado.org/gov/lead/FINAL_Rico_Blood_Lead_Report_Feb-13-2007.pdf


Synchrotron Analysis Studies Supports Hypothesis That Pb in Outdoor Soil Is Significant Contributor to INDOOR dust Pb


Laidlaw et al. Sydney House and Soil XAS Study

Pingitore et al. 2011 - Contributions of Paint and Soil to Pb in Household Dust Wipes: An XAS Study

Maclean et al. 2011 - Application of Synchrotron X-ray Techniques for the Determination of Metal Speciation in (House) Dust Particles


Plot of Temporal Variation in Atmospheric Soil and Lead in Detroit - 2001-2009


This plot shows that soil that has been resuspended into the atmosphere is highly correlated with air lead concentrations. This is important as it indicates that air lead levels are linked with surficial soil lead concentrations. Therefore, reducing air lead concentrations must involve isolation of urban lead contaminated soils

Scatterplot with median splines of weather adjusted air lead and air soil in time (daily). Weather-adjusted air Pb and soil estimates (µg/m3) are graphed on the daily time-step, fitting distributions of air Pb and soil values with median splines.

Source - Zahran S., Laidlaw M.A.S., McElmurry S.P., Filippelli G.M. Taylor M. (2013)

Supplemental Material


Plot of Temporal Variation in Atmospheric Lead and Children's Blood Lead in Detroit - 2001-2009


This plot shows that children's blood lead levels are highly correlated with atmospheric lead concentrations (which are correlated with atmospheric soil on the previous page). This is important as it is apparent that to reduce children's blood lead levels, soil lead contamination must be isolated. Furthermore, this plot indicates that Pb paint (the erroneous paradigm of blood lead causality) cannot be attributable to seasonal variations in children's blood lead levels.

Weather-adjusted air Pb (µg/m3) and blood Pb (µg/dL) by age group. Average monthly child blood Pb levels adjusted by local weather conditions, child gender, method of blood draw, and census tract fixed effects

Source - Zahran S., Laidlaw M.A.S., McElmurry S.P., Filippelli G.M. Taylor M. (2013)

Supplemental Material


Early Childhood Lead Exposure and Academic Achievement:Evidence From Detroit Public Schools, 2008–2010 (Zhang et al, 2013)


In the maps of soil lead concentration below, note that the California residential soil lead guideline is 80 mg/kg

Link

New Orleans, Louisiana (USA)


This chart shows that the inner city soils of New Orleans are highly contaminated with lead. This bullseye pattern is typical of large cities that used lead in gasoline for many years. Unfortunately, the residents of many inner-city areas in the US are African American and Hispanic.

mielke.jpg


Soil Pb content and corresponding soil Pb loading of the communities of New Orleans

The figure below is particularly important because it shows the soil Pb content along with the corresponding soil Pb loading of the communities of New Orleans. The map illustrates the difference between common measurements of soil Pb and the quantities of Pb on the soil surface that children are likely to encounter during outdoor play activities. The 2013 standard for dust Pb loading on interior floors is ~431 µg/m2 (40 µg/ft2 based on U.S. standards). Note that in this figure soil containing the minimum Pb of 6 µg/g has a Pb loading value of ~430 µg/m2 and that soil containing 400 µg/g, the U.S. HUD, EPA and CDC standard, has a Pb loading value of ~16,200 µg/m2 . This means that the U.S. EPA soil Pb standard poses a Pb loading value in outside environments which is over 37 times larger than the Pb dust standard allowed on floors within home interior environments

no3d.jpg

Source - 2014 Evolving from reactive to proactive medicine-community lead and clinical disparities (Mielke et al., 2014)


New Orleans Soil Pb Blood Pb Relationship At Various Soil Pb Guidelines Levels Using Mielke's Empirical Dataset


The USEPA's soil Pb residential guideline is 400 mg/kg. The first chart shows that as soil lead levels increase, children's blood lead levels increase. The second chart (below) indicates the blood lead response of children's blood lead levels (of various age groups)to an exposure of soil lead of 400 mg/g (based upon Mielke's empirical study). This chart indicates that an exposure of 400 mg/kg will result in a blood lead exceeding 5 micrograms per declitre (the current CDC blood lead reference level). Note that lead is not safe at any level.It also shows what the blood lead level response would be using Norways guidelines. In essence, based upon the current CDC reference level and the empirical soil lead blood blood lead relationship, this chart shows that the 400 mg/kg guideline is inadequate and that it would be appropriate to adopt the Norwegian guideline (note that the California guideline is 80 mg/kg). However this has major implications given the large regions in urban areas exceeding 100 mg/kg.

Link to Source




Syracuse, New York

syracuse.jpg

Link to Source



Link to Source

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

The interesting thing about this map is that it is only based on a sample of 8% of the children in Indianapolis. Moreover, one study of the NHANES data indicated that for every case of blood lead exceeding 10 micrograms per decilitre, there were 7.7 cases exceeding 5 micrograms per decilitre. Note that lead is not safe at any level.

Link to Source




Chicago, Illinois


Unfortunately, the African-American and Hispanic populations have the highest exposure in Chicago. This situation appears to be happening in many of the major inner-cities of the USA. The exposure results from a combination of lead in soil dust, flaking lead paint dust and lead water lines. The absence of any efforts to investigate, remediate or educate the public regarding the lead in dust soil exposure pathway in areas predominantly comprised predominantly of African Americans and Hispanics brings some to question whether environmental racism is occurring. Some people ask the question whether urgent action would have occured if this situation was present in white suburban areas.


Spatial Patterns and Health Disparities in Pediatric Lead Exposure in Chicago: Characteristics and Profiles of High-Risk Neighborhoods

LEAD CONTENT OF SOILS ALONG CHICAGO'S EISENHOWER AND LOOP-TERMINAL EXPRESSWAYS

Link to separate United States Geological Survey (USGS)Soil Lead Study of Chicago

chicago.jpg

Distribution of soil lead in 87 Chicago Gardens - Finster et al. (2003)

Pilot Study of the Relationship of Regional Road Traffic to Surface-Soil Lead Levels in Illinois (Argonne National Laboratory, 1987)

Gasoline Pb in soil of Chicago Play Areas (Argonne National Laboratory, 1986)


Link to Philadelphia, Pennslyvania - Soil Lead Map

Philadelphia, Pennslyvania : Lead Poisoning Risk Analysis

Link to Source




Oakland, California

syracuse.jpg


Los Angeles, California

Quote from the conclusion of this paper (Wu et al., 2010): "This study found that areas occupied by majority (population ratio larger than 50%) African American and Hispanic populations have higher soil lead concentrations than Non-Hispanic Whites (data not shown). This finding implies that minority groups in the study area have a higher potential for exposure to lead from soils. Considering the higher birth rates in minority populations, especially people of Hispanic descent, it is likely that lead from soils plays a greater role in childhood blood lead poisoning in children who live in these areas". Note that the soil lead concentrations on this map represent the bioavailable portion of the soil which is easily transferred to the bloodstream when ingested or inhaled. The total concentration for these calculations, which are presented on all the other maps on this site, have much higher concentrations.

syracuse.jpg


Link to paper

Link to California Soil Lead Studies


Sacramento, California

sacramento.jpg


Link to Solt Thesis

Link to California Soil Lead Studies


California Automotive Pb Emissions: 1950 to 1982

Link to Source

Link to California Soil Lead Studies


Minneapolis and St. Paul Minnesota(USA)

TwinCities


El Paso, Texas

Link to Source

Source - SCERP Monograph Series no. 12, The U.S-Mexican Border Environment: Integrated Approach to Defining Particulate Matter Issues in the Paso del Norte Region.

Link to CDC El Paso Discussion of Study




Paris, France

Link to Source




Great Britain

The British Geological survey systematically sampled Pb in the soils of 22 cities in Great Britain - Link.

Moscow, Russia

Link to Source


Prague, Czech Republic

Link to Source


Europe

Link to Source


London, England

Link to Source


Glasgow, Scotland

Link to Source


Sydney, Australia

Link to Source


Link to Source


Christchurch, New Zealand


Omaha, Nebraska

Link to Source



Berlin, Germany - Soil Lead Map

Karlsruhe, Germany - Soil Lead Map



Blood Lead Incidence Maps



The blood lead incidence rates in most large urban areas of the United States are probably similar to those shown on the blood lead incidence maps of Detroit, Milwaukee, and Cleveland (below).

Chicago, Illinois

Spatial Patterns and Health Disparities in Pediatric Lead Exposure in Chicago: Characteristics and Profiles of High-Risk Neighborhoods

Milwaukee, Wisconsin

Milwaukee Soil Lead Study

2009 Milwaukee Blood Lead Seasonality Study

Older Milwaukee Blood Lead Seasonality Study

Milwaukee Soil Lead Study


Source

Cleveland, Ohio- Soil Lead




Detroit, Michigan

Note the soil lead background concentrations in Detroit's northern suburbs.

Link to Source of Figures 4 and 5



Plot of Soil Lead Versus Children's Blood Lead in Detroit - Bickell 2010

View Lead Poisoning Percentages in Each Detroit School

Source - Detroit Free Press


Providence, Rhode Island

Link to Source


Grand Rapids, Michigan

Source


Louisville, Kentucky


Note the blood lead in areas built after 1950 when most of lead was eliminated from paint.

Source


In many urban inner-city areas of the United States, there is an epidemic of childhood blood lead poisoning (Gould, 2009). It has been estimated that 24.5%, or 9.6 million U.S. children have a blood lead in the range of 2 to 10 micrograms per decilitre, a level which will cause sub-clinical signs (Gould, 2009). The National Health and Nutrition Examination Survey (NHANES) III 1999-2002 database indicates that approximately 2.4 million children have blood Pb levels between 5 and 9.9 microgram/deciliter (Iqbal et al., 2008) and that within that population of 1-'5-year olds with blood Pb levels of 5 microgram/deciliter or higher, the prevalence was 47% for non-Hispanic Black children, 28% for Mexican American children, and 19% for non-Hispanic White children (Bernard and McGeehin, 2003). The fact that children of color are nearly 4 times more likely than white children to have blood Pb levels between 5 and 10 microgram/deciliter (and 13 times more likely to have blood Pb levels above 20 microgram/deciliter) (Bernard and McGeehin, 2003) raises concerns about social justice and the long-term health of these children. In addition, in 2004, in 10 ABLES states, a total of 10,527 females aged 16--44 years were tested, and all BLLs for this group were reported. Of the number tested, 1,370 (13.0%) had BLLs >5 µg/dL (10.9 per 100,000 female residents aged 16--44 years). I have not located the breakdown by race or by urban versus suburban area yet.


Dose-Response-USEPA IEUBK Model



Dose Response - Empirical Relationships


Note that the empirical relationship between soil lead and blood lead observed in New Orleans (below) and Detroit (below) displays steeper slopes than the USEPA IEUBK model (above). This could possibly suggest that IEUBK model is under-predicting blood lead levels at lower concentrations.

New Orleans - Soil Lead Blood lead - Empirical Relationship



Dose-Response - Detroit


Plot of Soil Lead Versus Children's Blood Lead in Detroit - Bickell 2010

Source - Bickell (2010)


  • Lanphear et al. (1998): increasing soil lead concentration from background to 400 micrograms/g was estimated to produce an increase of 11.6% in the percentage of children estimated to have a blood lead level exceeding 10 micrograms/dL.

  • Malcoe et al. (2002): Logistic regression of yard soil lead >165.3 mg/kg (OR, 4.1; CI, 1.3-12.4) were independently associated with BPbs greater than or equal to 10 microg/dL.

  • Texas Dept. of Health (2004): Using large database from El Paso Area, study found an odds ratio 4.5 (1.4, 14.2)for the relationship between a 500 ppm increase in soil lead and blood lead level > 10 ug/dl.

  • Maisonette (1997): yard soil remediation showed the strongest association with changes in blood lead levels. This variable was found to be a protective factor for elevated blood lead levels in children (odds ratio, 0.28; confidence interval, 0.08-0.92).



2011 Lead Poisoning Health Effects Review Paper - Highly Recommended!




Childhood lead poisoning (Zahran et al., 2013a), (Zahran et al., 2013b) and preeclampsia/eclampsia (Zahran et al., 2014) have been shown to be associated with lead in soil and dust.


1) Childhood lead poisoning is one of the most common pediatric health problems in the United States today (CDC, 2014); Source
2) “Preeclampsia ... is the leading cause of maternal death worldwide and a major cause of preterm delivery”.... "Predicting preeclampsia is a major step towards saving the lives of many women”.Source


Link to a very recent review of the association between lead and preeclampsia/eclampsia/hypertension


2012 Association Between Aggravated Assault and Air Pb - Six City Study - Highly Recommended!



IF it is assumed that there is causality between lead exposure and violent attacks, what does that say about the culpability of those who were placed in prisons as a result of the lead peak, as well as those inprisoned due to violence in the inner cities? I do not know the answer.


Toxicity of low level Pb exposure typically caused by exposure to Pb in soil dust


Low PbB levels (<10 ug/dL) typically associated with urban soil Pb exposure are associated with a myriad of health outcomes. Low PbB levels (<10 ug/dL) are associated with Attention-Deficit Hyperactivity Disorder (ADHD)(Nigg et al., 2010), a reduction in children’s tests scores for reading (odds ratio = 0.51, p = 0.006) (Chandramouli et al., 2009), writing (odds ratio = 0.49, p = 0.003) (Chandramouli et al., 2009; Miranda et al., 2007) and mathematics (Miranda et al., 2007). Canfield et al. (2003) observed that when lifetime average PbB concentrations in children increased from 1 to 10 mg/dL, the intelligence quotient (IQ) declined by 7.4 points. Jusko et al. (2008) observed that compared with children who had lifetime average PbB concentrations < 5 mg/ dL, children with lifetime average concentrations between 5 and 9.9 mg/dL scored 4.9 points lower on Full-Scale IQ (91.3 vs. 86.4, p = 0.03). Similarly, Surkan et al. (2007) observed that children with 5-10 mg/dL had 5.0 (S.D. 2.3) points lower IQ scores compared to children with PbB levels of 1-2 mg/dL (p = 0.03). Interestingly, multiple studies have shown that that the strongest Pb effects on IQ occurred within the the first few micrograms of PbB (Schnaas et al., 2006; Canfield et al., 2003; Lanphear et al., 2005). Low PbB levels (<10 ug/dL) have also been associated with various physiological outcomes such as kidney damage (Fadrowski et al., 2010), dental caries (Moss et al., 1999), puberty delay in boys (Williams et al., 2010) and girls (Selevan et al., 2003) and cardiovascular outcomes in adults (Navas-Acien et al., 2007).




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.

Zahran S, et al. Children's blood lead and standardized test performance response as indicators of neurotoxicity in metropolitan New Orleans elementary schools, Neurotoxicology (2009), doi:10.1016/j.neuro.2009.07.017

Chandramouli, L. et al. 2009. Effects of early childhood lead exposure on academic performance and behaviour of school age children. Archives of Disease in Childhood. Online First: 21 September 2009. doi:10.1136/adc.2008.149955

2009_Miranda_Environmental_contributors_to_the_achievement_gap

Accompanying powerpoint pdf

Nigg JT, Nikolas M, Mark Knottnerus G, Cavanagh K, Friderici K. 2010. Confirmation and extension of association of blood lead with attention-deficit/hyperactivity disorder (ADHD) and ADHD symptom domains at population-typical exposure levels. J Child Psychol Psychiatry. 51(1):58-65.

Lucchini, RG, S Zoni, S Guazzetti, E Bontempi, S Micheletti, K Broberg, G Parrinello and DR Smith. 2012. Inverse association of intellectual function with very low blood lead but not with manganese exposure in Italian adolescents. Environmental Research http://dx.doi.org/10.1016/j.envres.2012.08.003.

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.


Detroit Blood Lead and School Outcomes


Source


Hu et al. (2014) - Associations between blood lead level and substance use and sexually transmitted infection risk among adults in the United States


Solution - Remediation Precedent Set in New Orleans, Evansville and Omaha


1.) Method of Mielke et al.(2011) - New Orleans

"The soil emplacement was conducted by first spreading out a bright orange, water pervious geotextile material to cover the original soil of the play area. The geotextile layer prevents Pb-safe soil from mixing with the underlying original soil and acts as a warning layer to anyone digging into soil. Soil was not removed from the play areas in this project. The Pb-safe soil was from the Bonnet Carré Spillway, located up-river from New Orleans (U.S. ACE or Army Corps of Engineers). The alluvial soil, derived from the sediments of the Mississippi River at the Bonnet Carré Spillway, has a median Pb content of 5 mg/kg (Mielke et al., 2000). The Bonnet Carré soil was transported to the childcare center and emplaced on top of the geotextile layer to a depth of at least 15cm(6 inches)."


Source


2.) USEPA Method - "dig and dump"(more costly than Mielke's Method)

EPA Region 7 Completes 10,000th Residential Yard Cleanup of Lead-Contaminated Soils at Omaha Lead Site in Omaha, Neb.

Jacobsville Neighborhood Lead Contamination Superfund Site Newsletter - May 2011


Soil lead exposure reduction in the inner cities will improve health, increase students cognitive abilities and provide jobs, perhaps to inner-city residents.

3.) Boston Pilot Program - Landscaping Mitigates Lead Poisoning
4.) Safe Yards: Improving Urban Health through Lead-Safe Yards (Litt et al., 2002)

EPA and Partners Celebrate Reduced Lead Exposure in Children; Blood lead levels in children around Tar Creek site in Okla. greatly reduced.


Children in Tar Creek and Ottawa County, Oklahoma had historically been exposed to high levels of lead from former mining operations, especially around the Tar Creek Superfund site. In 1997, 21.5 percent of children living near Tar Creek showed elevated blood levels, defined as readings above 10 µg/dl (micrograms per deciliter). For the same year, 12.61 percent of children in Ottawa Co., OK, showed elevated levels. Since then, through EPA, state, and tribal cleanup activities, lead-contaminated soil has been removed from 2,887 residential yards and public properties in the area. With additional funding from EPA, the Ottawa County Health Department has worked to increase community awareness about lead poisoning prevention and the importance of blood lead screening for children. These activities have achieved striking results, with 0 percent of area children showing elevated levels [>10 micrograms per decilitre] in 2013.


Link.

Simple Non-toxic Way Forward

1.) Cut lawn as low as possible 2.) Lay down Bright Orange Geotextile 3.) Terraseeding (soil and seed mix) -0r- 3.) Apply Topsoil Using Topsoil Slinger & 4.) Hydroseed During Spring

Geotextile

Geotextile link

Topsoil Slingers

Topsoil Slinger Video # 1

Topsoil Slinger Video # 2

Topsoil Slinger Video # 3

Topsoil Slinger Video # 4

Terraseeding (mix soil and grass seed)

Terraseeding

Hydroseeding

Hydroseeder Video # 1


Soil Treatment Strategy

I recommend that soil covering efforts first be conducted in areas where there is a high prevalence of lead poisoning and where soil lead levels are high (triage). I would first focus on roadside soils (0-25m)within these areas and then continue until areas with high lead poisoning prevalence are covered (or funds permit).


Estimated Cost of Urban Soil Lead Remediation - New Orleans


In the journal Environmental Science and Technology, Mielke et al. (2006) estimated the cost to remediate the soils in New Orleans. The abstract is presented below:


In New Orleans, LA prior to hurricane Katrina 20−30% of inner-city children had elevated blood Pb levels ≥10 μg/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 μg/ft2 to a median of 36 μg/ft2 (25th and 75th percentiles are 22 and 142 μg/ft2 and 12 and 61 μg/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.



Estimated Benefit of National Urban Pb Paint and ?Soil? Lead Remediation - United States


Gould, 2009 estimated that the net benefit of lead hazard control ranges from $181 to $269 billion, resulting in a return of $17–$221 for each dollar invested in lead hazard control. Note that the cost benefit by Gould did not include the cost benefit of reductions in autism, preeclampsia, schizophrenia, mental illness and many other diseases associated with lead poisoning. Thus the benefit of lead hazard reduction is likely to be much greater than Gould's estimates.


Recommended Funding Mechanism To Cleanup Urban Soils


Small Gasoline Tax!


Call For Blood Lead Incidence Data Transparency


I strongly suggest that the new Obama government publish child blood lead incidence maps of the top 50 cities in the U.S by graphically displaying the location and all the blood lead concentrations (>5 ug/dl, > 10ug/dl and >20 ug/dl) for the previous 5 years, and updated yearly (see Detroit Blood Lead Incidence Map Above). The percentage of the children sampled should be boldly presented as well. These maps should be available for all to see on one central internet site. The website would be registered with all the major search engines so that anyone could locate the data. This data is already available and could easily be put together in a two month time period by someone experienced in GIS and the internet. The funding cost would be extremely small.

See Dot Maps of Children's Lead Poisoning in Various Wisconsin Cities


The public has a right to know.

Call For National Urban Soil Geochemical Risk Mapping Program


I suggest that the Obama administration use the United States Geological Survey to conduct an urban soil geochemical risk mapping program in the 50 largest cities in the United States. I recommend the geochemical mapping methods be adopted fromthe British Geological Survey, David L Johnson/colleagues at SUNY-ESF or Howard Mielke and colleagues at Tulane/Xavier. The results should be placed online in one central location for anyone to view.


Additional Lead Thoughts


1.)The USEPA's 400 mg/kg soil guideline is not protective of human health. A safe guideline would be about 75 to 100 mg/kg. The California draft soil lead guideline is 80 mg/kgLink. The Minnesota (USA) soil lead guideline is 100 mg/kg and the Dutch guideline is 40 mg/kg. See the dose-response curves of Mielke and Johnson's soil lead-blood lead ecological study design above. Risk assessments that have argued to leave lead concentrations higher than 400 mg/kg (and higher than 100 mg/kg) are deeply flawed and these areas will have to be revisited when a lower guideline level is adopted by a bold USEPA, if that ever happens;

2.) There is a glaring disconnect between the actions of the USEPA and the CDC. While the USEPA is cleaning up 10's of thousands of lead contaminated yards in Tar Creek, Omaha and Evansville under the Superfund program, the CDC does not have any money appropriated to the investigation and remediation of URBAN contaminated soil and continue with the paradigm that lead poisoning is caused primarily by lead paint. No money has been appropriated by either the USEPA or the CDC for the investigation and remediation of non-Superfund cities, of which many are just as contaminated Tar Creek, Omaha and Jacobsville;

3.) Why has the USEPA or the United States Geological Survey NOT conducted soil lead surveys of the largest cities in the United States like the British Geological Survey has completed in Great Britain? Would this have been done if the inner-city residents were white and wealthy and not composed of the urban poor, african americans and hispanics? It seems that the USGS can measure and assess lead in birds and pesticide contaminants in urban streams etc. etc. but not lead in urban soil, children or pregnant women?

4.) I think most people assume that the USEPA must have done alot of URBAN studies and have teams of researchers who have been on top of this? The USEPA has done very few URBAN studies and seems to be doing very little URBAN research based upon the lack of publications on this topic. So who is doing the research? Very very few academic scientists who have been doing research with an almost total lack of funding!

5.)It is very perplexing that many billion dollars have been spent remediating and investigating leaking underground storage tanks (USTs) across the US and internationally when there are actually very few complete exposure pathways, while there has been a TOTAL absence of funding on research and ACTION regarding urban soil lead contamination and children's lead exposure issues. This makes no sense given the widespread lead poisoning epidemics at levels that are well documented to cause deleterious health effects in inner-city urban children and pregnant women.


There are three basic things that can be done:


1) Do nothing (this is what the current approach is); 2) Remediate (cover soils/remove flaking paint & Pb lines); 3) Move pregnant women and children away from source area.

History of Lead


To read the REAL history of Lead in Gasoline, read The Ethyl Controversy by Professor William Kovarik.

Kovarik W. Ethyl-leaded gasoline. How a classic occupational disease became an international public health disaster. Int J Occup Environ Health 2005;11:384-397.

CalTech Masters Thesis on Clair Patterson

Kitman - Secret History of Lead (summary)

Kitman - Secret History of Lead (full version)

Rosner, D., and G. Markowitz 2005. Standing up to the lead industry: An interview with Herbert Needleman. Publ Health Reports 120:330-7.

Markowitz, G., and D. Rosner 2002. Deceit and Denial: The Deadly Politics of Industrial Pollution. University of California Press.




Children's Blood Lead Levels Also Display Strong Seasonal Variations With Peaks Generally in the Summer or Autumn When Soils Are Dry and Prone to Resuspension



A conceptual model of child BPb seasonal Pb poisoning is suggested. Lead from multiple sources has accumulated in soils of urban environments. The seasonal resuspension of Pb-contaminated soil in urban atmospheres appears to be controlled by soil moisture and climate fluctuations. This study (Laidlaw et al., 2005)indicates that higher urban atmospheric Pb loading rates are experienced during periods of low soil moisture and within areas of Pb-contaminated surface soils. Children and adults living in urban areas where surface soils are contaminated with Pb may become exposed through indoor and outdoor inhalation of Pb dust and ingestion of Pb deposited within homes and outdoor surfaces. Because resuspension of Pb from contaminated soil appears to be driving seasonal child BPb fluctuations, concomitantly, we suggest that Pb-contaminated soil in and of itself may be the primary driving mechanism of child BPb poisoning in the urban environment.

Link to source

Laidlaw et al.'s (2005) model used in the three cities above was independently replicated in Milwaukee, Wisconsin in an unpublished court case





Soil Lead is a Major Source of Atmospheric Lead via Soil Re-suspension


Weather adjusted air Pb and air soil over time, including median spline fits, for Pittsburgh, Detroit, Chicago and Birmingham.



Weather adjusted air lead versus air soil with linear fit for peak months (June, July, August, and September) and non peak months (October through May) for Pittsburgh, Detroit, Chicago and Birmingham combined.




This study also observed..."Atmospheric soil and lead aerosols are 3.15 and 3.12 times higher, respectively, during weekdays than weekends and Federal Government holidays, suggesting that automotive traffic turbulence plays a significant role in re-suspension of contaminated roadside soils and dusts."

Source - Mark A.S. Laidlaw, Sammy Zahran, Howard W. Mielke, Mark P. Taylor, Gabriel M. Filippelli. 2011. Atmospheric Environment.


Plot of Temporal Variation in Atmospheric Soil and Lead in Detroit - 2001-2009

Scatterplot with median splines of weather adjusted air lead and air soil in time (daily). Weather-adjusted air Pb and soil estimates (µg/m3) are graphed on the daily time-step, fitting distributions of air Pb and soil values with median splines.

Source - Zahran S., Laidlaw M.A.S., McElmurry S.P., Filippelli G.M. Taylor M. (2013)

Supplemental Material


Plot of Temporal Variation in Atmospheric Lead and Children's Blood Lead in Detroit - 2001-2009

Weather-adjusted air Pb (µg/m3) and blood Pb (µg/dL) by age group. Average monthly child blood Pb levels adjusted by local weather conditions, child gender, method of blood draw, and census tract fixed effects

Source - Zahran S., Laidlaw M.A.S., McElmurry S.P., Filippelli G.M. Taylor M. (2013)

Supplemental Material


Early Childhood Lead Exposure and Academic Achievement:Evidence From Detroit Public Schools, 2008–2010 (Zhang et al, 2013)


Recently Released - Relationship of Pb in House Dust and Ambient Air (Gulson and Taylor, 2014)

Rio-Salas et al. (2012) - Atmospheric Environment - Study of urban soil Pb re-suspension

I suggest that when the soil is resuspended, the fine fraction where the bulk of the petrol lead particles reside is suspended in the air. This fraction has a higher concentration than the bulk soil and also has a different isotopic signature (more anthropogenic) than the bulk soil. It is also suggested that air lead concentrations can result in very high concentrations at a height of two (m) in the summertime in cities where the soil lead concentrations are an order of magnitude higher than this Mexican city. It does not take much imagination to understand that air lead concentrations at two metres are at the same height as windows which likely results in air lead penetration into homes.


Source - Rio-Salas et al. (2012




Atmospheric Soils Are Resuspended With Peak Concentrations in the Summer and Autumn in the U.S.


It is believed that this process is resuspending urban lead contaminated soils in the summer and autumn.


The same summertime seasonality was observed for Total Suspended Particulates (TSP), Nickel, Iron and Sulfur in Esperance, Western Australia. Note summer in Esperance occcurs between November and February.





Link to Source


Washington DC Atmospheric Lead Seasonality



Link to Source



2.) Author:Nicholas E. Pingitore, Jr.1,2*, Juan W. Clague1, Maria A. Amaya2, Beata Maciejewska1, Jess J. Reynoso3
Title:Urban Airborne Lead: X-Ray Absorption Spectroscopy Establishes Soil as Dominant Source
Source: PLOS One Link

http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0005019



Despite the dramatic decrease in airborne lead over the past three decades, there are calls for regulatory limits on this potent pediatric neurotoxin lower even than the new (2008) US Environmental Protection Agency standard. To achieve further decreases in airborne lead, what sources would need to be decreased and what costs would ensue? Our aim was to identify and, if possible, quantify the major species (compounds) of lead in recent ambient airborne particulate matter collected in El Paso, TX, USA.

Methodology/Principal Findings: We used synchrotron-based XAFS (x-ray absorption fine structure) to identify and quantify the major Pb species. XAFS provides molecular-level structural information about a specific element in a bulk sample. Pb-humate is the dominant form of lead in contemporary El Paso air. Pb-humate is a stable, sorbed complex produced exclusively in the humus fraction of Pb-contaminated soils; it also is the major lead species in El Paso soils. Thus such soil must be the dominant source, and its resuspension into the air, the transfer process, providing lead particles to the local air.

Conclusions/Significance: Current industrial and commercial activity apparently is not a major source of airborne lead in El Paso, and presumably other locales that have eliminated such traditional sources as leaded gasoline. Instead, local contaminated soil, legacy of earlier anthropogenic Pb releases, serves as a long-term reservoir that gradually leaks particulate lead to the atmosphere. Given the difficulty and expense of large-scale soil remediation or removal, fugitive soil likely constrains a lower limit for airborne lead levels in many urban settings.




Urban Atmospheric Lead Is Associated with Particulate Matter Less Than 10 micron in Size (PM10)


Mexico City - 1991

Link to source


Blood Lead Seasonality



Note the blood lead seasonal patterns below. Whatever drives these seasonal blood lead changes is the major driving force of urban blood lead poisoning.



Unknown City

source- The Lead debate: the environment, toxicology and child health By Richard Lansdown, William Yule



Chicago, Illinois

syracuse.jpg

source



Lansing, Michigan

syracuse.jpg

source



Milwaukee,Wisconsin (USA)-New

Link to source

">Link to source



Milwaukee,Wisconsin (USA)-Old

USEPA Discussion - p. 45 "Exposure may increase in the summer because of factors that include increased outdoor playing time, more opening and closing of windows, increased hand-to-mouth activity, and drier leaded dust that more easily enters homes."

Link to source

Milwaukee Soil Lead Study


St. Louis,Missouri (USA)

Link to source

Link to Another St. Louis Source


Birmingham, England

Link to source


Seasonality of Lead Loading in the Interior of a Northern England House

source


Blood Lead Seasonality in Buxton, England - 1972


Boston,Massachusetts (USA)

Link to source

USEPA state on page iV, ...."Modeled lead levels for air, floor dust and furniture dust all had peaks in July"

New York State, (USA)

Link to source


New York City Atmospheric Lead: 1970-1976

Link to source


New York City Blood Lead Seasonality: 1970-1976

Link to source

Note that the summertime atmospheric lead peaks coincided with the blood lead peaks. It is suggested that current blood lead peaks are also caused by exterior atmosperic lead summertime peaks.

Los Angeles, California (USA)

Link to source

Link to California Soil Lead Studies


Jersey City, New Jersey (USA)

http://www.ehponline.org/members/2000/108p177-182yiin/108p177.pdf


State of New Jersey - 2000 to 2004 (USA)

New Jersey Department of Health and Senior Services Consumer and Environmental Health Services Environmental Public Health Tracking Project. 2007. Analysis of Risk Factors for Elevated Levels of Blood Lead in New Jersey Children, 2000-2004 Demonstration Project on Geographic Patterns of Childhood Blood Lead and Environmental Factors in New Jersey.


Baltimore, Maryland & New York City (USA)

http://www.restena.lu/lhce/Chimie/Publications/PDF/2_lead_poisoning.pdf


Chicago, Illinois(USA)

http://www.ajph.org/cgi/reprint/54/8/1241.pdf


New Haven, Connecticut(USA)

Source


UNTESTED Hypothesis for the declines in blood lead levels Following the elimination of lead in gasoline


I have questioned whether the decline if in blood levels following the elimination of lead in gasoline has resulted because in urban areas highly contaminated soils have been resuspended year after year. What could be happening is that a sizable percentage of the resuspended soil and lead falls on impervious surfaces such as roofs and roadways. This material could have then been brought out of the system depositing into sediments in rivers and estuaries. This could conceivably be reducing the lead concentrations in urban soils and subsequents exposures in the atmosphere through resuspension. The "signal" should be present in the sediments of estuaries. (indeed it is in Sydney, AUstralia - see Birch - University of Sydney). This is only a hypothesis at present.


Homegrown Vegetables Are Another Exposure Pathway to Lead in Urban Soil


The recent movement towards cultivating homegrown vegetables, partly due to the global financial crisis, poses risks due to the uptake of lead in certain vegetables.

The following documents have been selected to educate the reader:

Garden Safe, Garden Well (Gabriel Filippelli, IUPUI)

2011 - Gardening and Lead Review Paper

Chicago Illinois Lead Uptake in Vegetables Study

Home Gardening in Lead Contaminated Soil

Gardening on Lead- and Arsenic-Contaminated Soils

Heavy metals contamination of home grown vegetables near metal smelters in NSW

Sustainable Gardening Information Page

Vegetable Consumption and Blood Lead Concentration

Eggs Laid in Urban Areas Can Be Contaminated with Lead



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.




Author:Angle Carol;McIntire Matilda
Title:Environmental lead and children: The Omaha study
Journal:Journal of Toxicology and Environmental Health Volume 5, Issue 5 September 1979 , pages 855 - 870
Abstract:Blood lead (Pb B) was determined in 1232 samples from 831 children in Omaha and correlated with air lead (Pb A) concentrations of 0.02-1.69 μg/m3 from 1971 to 1977. A bivariate equation for ages 6-18 yr based on these data predicts on increase in Pb B of 1.4 μg/dl as Pb A increases from 1 to 2 μg/m3. Pb B increases 7 μg/dl as the mean values for soil and house dust Pb increase from 100 to 750 μg/g. Multiple regression analysis shows that the combined effects of air, soil, and house dust Pb account for 21% of the variance of Pb B, with a high intercorrelation of all 3 variables. Since the variance of repeat sampling in individuals accounted for 38% of the total variance of Pb B, approximately 40% is unexplained and requires measurement of Pb from dietary and other sources.


Reference Type: Journal Article
Record Number: 14
Author: Alonso, E.; Cambra, K.; Martinez, T.
Year: 2001
Title: Lead and cadmium exposure from contaminated soil among residents of a farm area near an industrial site
Journal: Archives of Environmental Health. 56(3)
Volume: 56(3)
Pages: 278-82
Accession Number: 11480506
Abstract: In this study, the authors determined the degree of lead and cadmium exposure in a population that resided in an area with contaminated soil. The extent of exposure from soil pollution was also assessed. Lead and cadmium concentrations in blood of children and adults who resided in the contaminated area were measured, and cadmium concentration in urine of adults was also determined. An adult control group was recruited from a nonpolluted area. The mean blood lead level in adults who resided in the polluted area was 9.8 microg/dl, compared with a mean level of 6.8 microg/dl in controls (p = .004). Urinary cadmium levels were well below the level associated with onset of symptoms, but the differences between levels in residents of the contaminated area (0.54 microg/gm creatinine) and levels in the controls (0.37 microg/gm creatinine) indicated that life-long cadmium exposure had been higher among the residents of the contaminated area (p = .086). The mean blood lead level and mean blood cadmium level in children were 5.2 microg/dl (maximum = 7.90 microg/dl) and 0.10 microg/l, respectively. Lead in soil accounted in large part for the differences in blood lead levels in children; however, blood cadmium levels were not associated with soil cadmium levels, but, rather, with consumption of home-grown vegetables.
Notes:
Journal Article


Reference Type: Journal Article
Record Number: 81
Author: Angle, C. R.; McIntire, M. S.
Title: Environmental lead and children: the Omaha study
Journal: Journal of Toxicology & Environmental Health.
Volume: 5(5)
Pages: 855-70.
Accession Number: 583166
Abstract: Blood lead (Pb B) was determined in 1232 samples from 831 children in Omaha and correlated with air lead (Pb A) concentrations of 0.02-1.69 microgram/m3 from 1971 to 1977. A bivariate equation for ages 6-18 yr based on these data predicts an increase in Pb B of 1.4 microgram/dl as Pb A increases from 1 to 2 microgram/m3. Pb B increases 7 microgram/dl as the mean values for soil and house dust Pb increase from 100 to 750 microgram/g. Multiple regression analysis shows that the combined effects of air, soil, and house dust Pb account for 21% of the variance of Pb B, with a high intercorrelation of all 3 variables. Since the variance of repeat sampling in individuals accounted for 38% of the total variance of Pb B, approximately 40% is unexplained and requires measurement of Pb from dietary and other sources.
Notes:
Journal Article



Reference Type: Journal Article
Record Number: 58
Author: Aschengrau, A.; Beiser, A.; Bellinger, D.; Copenhafer, D.; Weitzman, M.
Title: The impact of soil lead abatement on urban children's blood lead levels: phase II results from the Boston Lead-In-Soil Demonstration Project
Pages: 125-48, 1994 Nov.
Accession Number: 7982389
Abstract: The Boston Lead-In-Soil Demonstration Project was a randomized environmental intervention study of the impact of urban soil lead abatement on children's blood lead levels. Lead-contaminated soil abatement was associated with a modest reduction in children's blood lead levels in both phases of the project; however, the reduction in Phase II was somewhat greater than that in Phase I. The combined results from both phases suggest that a soil lead reduction of 2060 ppm is associated with a 2.25 to 2.70 micrograms/dl decline in blood lead levels. Low levels of soil recontamination 1 to 2 years following abatement indicate that the intervention is persistent, at least over the short-term. Furthermore, the intervention appears to benefit most children since no measurable differences in efficacy were observed for starting blood and soil lead level, race, neighborhood, gender, and many other characteristics. However, soil abatement did appear to be more beneficial to children in the higher socioeconomic classes, with low baseline ferritin levels, and who spent time away from home on a regular basis and lived in nonowner occupied housing, and with adults who had lead-related hobbies and almost always washed their hands before meals. Children who lived in apartments with consistently elevated floor dust lead loading levels derived almost no benefit from the soil abatement. It was not possible to separate the effects of the variables that had a beneficial impact on efficacy because they were closely correlated and the number of subjects was small. We recommend that further research be conducted to identify subgroups of children to whom soil lead abatement might be targeted.
Notes: Environmental Research. 67(2)
Clinical Trial
Clinical Trial, Phase II
Journal Article
Randomized Controlled Trial



Reference Type: Journal Article
Record Number: 39
Author: Aschengrau, A.; Beiser, A.; Bellinger, D.; Copenhafer, D.; Weitzman, M.
Year: 1997
Title: Residential lead-based-paint hazard remediation and soil lead abatement: their impact among children with mildly elevated blood lead levels
Journal: American Journal of Public Health.
Volume: 87(10)
Pages: 1698-702.
Accession Number: 9357358
Abstract: OBJECTIVES: This prospective study describes the impact of residential lead-based-paint hazard remediations on children with mildly elevated blood lead levels. METHODS: Changes in blood lead levels were observed following paint hazard remediation alone and in combination with soil abatement. RESULTS: After adjustment for the confounding variables paint hazard remediation alone was associated with a blood lead increase of 6.5 micrograms/dL (P = 0.5), and paint hazard remediation combined with soil abatement was associated with an increase of 0.9 microgram/dL (P = 36). CONCLUSIONS: Lead-based-paint hazard remediation as performed in this study, is not an effective secondary prevention strategy among children with mildly elevated blood lead levels.
Notes: Journal Article


Reference Type: Journal Article
Record Number: 53
Author: Bates, M.; Malcolm, M.; Wyatt, R.; Garrett, N.; Galloway, Y.; Speir, T.; Read, D.
Year: 1995
Title: Lead in children from older housing areas in the Wellington region
Journal: New Zealand Medical Journal.
Volume: 108(1009).
Pages: 400-4.
Accession Number: 7478332
Abstract: AIMS. To examine blood lead levels in children, aged 12 to 23 months, living in old housing areas of Wellington and Lower Hutt, and to investigate risk factors for high lead levels. METHOD. Children were selected from Plunket Society rolls. Venous blood samples were collected, and care givers were interviewed with a questionnaire. Soil samples were taken from around the children's homes. Both soil and blood samples were analysed for lead content. RESULTS. Blood samples and completed questionnaires were obtained for 143 children. The geometric mean blood lead level for all the children was 0.25 mumol/L (5.1 micrograms/dL) (95% confidence interval [95% CI]: 0.22-0.28 mumol/L). Three children had blood lead levels that exceeded the level for notification in New Zealand 1.45 mumol/L and a further 13 had blood lead levels exceeding 0.48 mumol/L. Children with elevated lead levels were likely to live in a house greater than 50 years old where paint removal had taken place in the last 2 years (risk ratio [RR] = 14.4, 95% CI: 2-107). Eating dirt, particularly for children who usually played outside within 2 metres of the house, was also a risk factor for elevated blood lead levels. Soil lead levels generally increased with the age of the house and were weakly correlated with blood lead levels (r = 0.32). CONCLUSION. Paint removal in old houses is a major risk factor for elevated blood lead levels. However, the number of study children living in houses less than 50 years old was limited. Because of this and possible participant selection bias, the results of this study require confirmation in a separate population-based study. Information about the specific paint removal procedures that cause high lead levels is also needed.


<Author: Michael E. Beard and S.D. Allen. 1995.
.
Title:Lead in Paint, Soil, and Dust: Health Risks, Exposure Studies, Control Measures, Measurement Methods, and Quality Assurance. ASTM STP 1226. Philadelphia: American Society for Testing and Materials.


Author: Binns HJ, Gray KA, Chen T, Finster ME, Peneff N, Schaefer P, Ovsey V, Fernandes J, Brown M, Dunlap B.
Title:Evaluation of landscape coverings to reduce soil lead hazards in urban residential yards: The Safer Yards Project.
Abstract:This study was designed primarily to evaluate the effectiveness of landscape coverings to reduce the potential for exposure to lead-contaminated soil in an urban neighborhood. Residential properties were randomized in to three groups: application of ground coverings/barriers plus placement of a raised garden bed (RB), application of ground coverings/barriers only (no raised bed, NRB), and control. Outcomes evaluated soil lead concentration (employing a weighting method to assess acute hazard soil lead [areas not fully covered] and potential hazard soil lead [all soil surfaces regardless of covering status]), density of landscape coverings (6 = heavy, > 90% covered; 1 = bare, < 10% covered), lead tracked onto carpeted entryway floor mats, and entryway floor dust lead loadings. Over 1 year, the intervention groups had significantly reduced acute hazard soil lead concentration (median change: RB, -478 ppm; NRB, -698 ppm; control, +52 ppm; Kruskal-Wallis, P = 0.02), enhanced landscape coverings (mean change in score: RB, +0.6; NRB, +1.5; control, -0.6; ANOVA, P < 0.001), and a 50% decrease in lead tracked onto the floor mats. The potential hazard soil lead concentration and the entryway floor dust lead loading did not change significantly. Techniques evaluated by this study are feasible for use by property owners but will require continued maintenance. The long-term sustainability of the method needs further examination.
SourceEnviron Res. 2004 Oct;96(2):127-38.



Reference Type: Journal Article
Author: Boreland F, Lyle DM.
Year: 2006
Title: Lead dust in Broken Hill homes: effect of remediation on indoor lead levels.
Journal: Environ Res.
Volume: 100(2)
Pages: 276-83
Abstract:This study was undertaken to determine whether home remediation effectively reduced indoor lead levels in Broken Hill, a long-established silver-lead-zinc mining town in outback Australia. A before-after study of the effect of home remediation on indoor lead levels was embedded into a randomized controlled trial of the effectiveness of remediation for reducing elevated blood lead levels in young children. Moist towelettes were used to measure lead loading (microg/m2) on internal windowsills and internal and entry floors of 98 homes; samples were collected before, immediately after, and 2, 4, 6, 8, and 10 months after remediation. Data were log(10) transformed for the analysis. Remediation reduced average indoor lead levels by approximately 50%, and lead levels remained low for the duration of the follow-up period (10 months). The greatest gains were made in homes with the highest initial lead levels; homes with low preremediation lead levels showed little or no benefit. Before remediation, homes located in areas with high soil lead levels or with "poor" dust proofing had higher lead levels than those in areas with lower soil lead levels or with "medium" or "good" dust proofing; these relative differences remained after remediation. There was no evidence that lead loading was reduced by an increased opportunity to become aware of lead issues. We conclude that remediation is an effective strategy for reducing the lead exposure of children living in homes with high indoor lead levels.


Author:Campbell C, Schwarz DF, Rich D, Dockery DW. 2003. Effect of a follow-up professional home cleaning on serial dust and blood lead levels of urban children. Arch Environ Health. Dec;58(12):771-80.
Abstract:Children residing in Philadelphia, Pennsylvania, who were enrolled in a clinical trial of oral chelation therapy (n=73) were studied to determine the effects of a follow-up professional lead dust cleaning of their homes 18 mo after an initial cleaning and commencement of therapy. Home dust lead levels were determined from dust-wipe specimens collected from the kitchen and playroom floors, and from a playroom windowsill, prior to, immediately following, and 3 and 6 mo after the second cleaning. Children's blood lead levels were assessed at 3-mo intervals before and after the follow-up cleaning. Professional cleaning produced immediate decreases in dust lead levels; however, dust lead re-accumulated to precleaning levels within 3-6 mo. Frequent, repeated cleanings may be required if blood lead or dust lead levels are to be reduced and sustained at low levels in urban homes.

Author:Caravanos, Jack, Weiss, Arlene and Jaeger, Rudolph. 2005. An exterior and interior leaded dust deposition survey in New York City: Results of a 2-year study. Environmental Research. Abstract: Environmental concentrations of leaded dust were monitored by weekly sample collection of interior and exterior settled dust that had accumulated due to atmospheric deposition. The weekly deposition amounts were measured and the cumulative rates of lead in dust that deposited on a weekly basis over 2 year's time were determined. The sampling analysis revealed that the median values of leaded dust for the interior plate (adjacent to the open window), unsheltered exterior plate, and the sheltered exterior plate were 4.8, 14.2, and 32.3 g/feet2/week, respectively. The data supports the existence of a continuous source of deposited leaded dust in interior and exterior locations within New York City. Additional data from a control plate (interior plate with the window closed) demonstrate that the source of the interior lead deposition was from exterior (environmental) sources. Because of the ubiquitous nature of lead in our environment and the toxic threat of lead to the cognitive health of children, this data provides a framework for the understanding of environmental exposure to lead and its potential for continuing accumulation within an urban environment.

Author:Caravanos, Jack, Blaise, Marc. J., Weiss, Arlene and Jaeger, Rudolph. 2005. A survey of spatially distributed exterior dust lead loadings in New York City Abstract: This work documents ambient lead dust deposition values (lead loading) for the boroughs of New York City in 2003-2004. Currently, no regulatory standards exist for exterior concentrations of lead in settled dust. This is in contrast to the clearance and risk assessment standards that exist for interior residential dust. The reported potential for neurobehavioral toxicity and adverse cognitive development in children due to lead exposure prompts public health concerns about undocumented lead sources. Such sources may include settled dust of outdoor origin. Dust sampling throughout the five boroughs of NYC was done from the top horizontal portion of pedestrian traffic control signals (PTCS) at selected street intersections along main thoroughfares. The data (n=214 samples) show that lead in dust varies within each borough with Brooklyn having the highest median concentration (730 g/ft2), followed in descending order by Staten Island (452 g/ft2), the Bronx (382 g/ft2), Queens (198 g/ft2) and finally, Manhattan (175 g/ft2). When compared to the HUD/EPA indoor lead in dust standard of 40 g/ft2, our data show that this value is exceeded in 86% of the samples taken. An effort was made to determine the source of the lead in the dust atop of the PTCS. The lead in the dust and the yellow signage paint (which contains lead) were compared using isotopic ratio analysis. Results showed that the lead-based paint chip samples from intact signage did not isotopically match the dust wipe samples taken from the same surface. We know that exterior dust containing lead contributes to interior dust lead loading. Therefore, settled leaded dust in the outdoor environment poses a risk for lead exposure to children living in urban areas, namely, areas with elevated childhood blood lead levels and background lead dust levels from a variety of unidentified sources.


Author:Leticia Carrizalesa, Israel Razoa, Jess I. Tllez-Hernndeza, Roco Torres-Nerioa, Arturo Torresa, Lilia E. Batresa, Ana-Cristina Cubillasb and Fernando Daz-Barrigaa,
Title:Exposure to arsenic and lead of children living near a copper-smelter in San Luis Potosi, Mexico: Importance of soil contamination for exposure of children
Abstract:The objective of this study was to assess the levels of soil contamination and child exposure in areas next to a primary smelter (arsenic copper metallurgical) located in the community of Morales in San Luis Potosi, Mexico. In Morales, 90% of the soil samples studied in this work were above 400 mg/kg of lead, and above 100 mg/kg of arsenic, which are guidelines recommended by the United States Environmental Protection Agency (EPA). Bioaccessibility of these metals was studied in vitro in 10 soil samples; the median values of bioaccessibility obtained in these samples were 46.5% and 32.5% for arsenic and lead. Since the concentrations of arsenic and lead in soil were above normal values, and taking into account the bioaccessibility results, exposure to these metals was evaluated in children. Regarding lead, children aged 3-6 years had the highest mean blood lead levels; furthermore, 90% of them had concentrations above 10 μg/dl (CDC's action level). Total urinary arsenic was higher in children aged 8-9 yr; however, the percentage of children with concentrations above 50 μg/g creatinine (CDC's action level) or 100 μg/g creatinine (World Health Organization [WHO] action level) was similar among different age groups. Using the EPAs integrated exposure uptake biokinetic model for lead in children (IEUBK), we estimated that 87% of the total lead in blood is obtained from the soil/dust pathway. The exposure dose to arsenic, estimated for the children living in Morales using Monte Carlo analysis and the arsenic concentrations found in soil, was above the EPA's reference dose. With all these results, it is evident that studies are needed in order to identify adverse health effects in children living in Morales; nevertheless, it is more important to develop a risk reduction program as soon as possible.
Notes:Environmental Research Volume 101, Issue 1 , May 2006, Pages 1-10


Reference Type: Journal Article
Record Number: 79
Author: Charney, E.; Sayre, J.; Coulter, M.
Title: Increased lead absorption in inner city children: where does the lead come from?
Pages: 226-31, 1980 Feb.
Accession Number: 7354967
Abstract: Pica for lead-containing paint has been questioned as the principal mechanism for the widespread moderately elevated blood lead levels (30 to 80 microgram/100 ml) in inner city children. This study explored the hypothesis that lead-contaminated household dust is a major source of lead for these children; hand contamination and repetitive mouthing is the proposed mechanism of ingestion. Forty-nine inner city children with blood lead 40 to 70 microgram/100 ml were matched with 50 children with blood lead less than or equal to 29 microgram/100 ml from the same inner city environment. House dust lead and lead on hands were found in significantly greater quantity among experimental subjects. Other factors differed between groups; lead content of peeling paint, soil lead, and pica affected more experimental than control children, but did not account for more than 50% of experimental cases. The cause of moderate blood lead elevation is multifactoral: no single source accounted for all children with elevated levels. However, lead contamination of house dust and hands appears to be a major factor in this condition.
Notes: Pediatrics. 65(2)
Journal Article


Reference Type: Journal Article
Record Number: 42
Author: Cikrt, M.; Smerhovsky, Z.; Blaha, K.; Nerudova, J.; Sediva, V.; Fornuskova, H.; Knotkova, J.; Roth, Z.; Kodl, M.; Fitzgerald, E.
Title: Biological monitoring of child lead exposure in the Czech Republic
Pages: 406-11, 1997 Apr.
Accession Number: 9189705
Abstract: The area around the Pribram lead smelter has been recognized to be heavily contaminated by lead (Pb). In the early 1970s, several episodes of livestock lead intoxication were reported in this area; thereafter, several epidemiological and ecological studies focused on exposure of children. In contrast to earlier studies, the recent investigation (1992-1994) revealed significantly lower exposure to lead. From 1986-1990, recorded average blood lead levels were about 37.2 micrograms lead (Pb)/100 ml in an elementary school population living in a neighborhood close to the smelter (within 3 km of the plant). The present study, however, has found mean blood lead levels of 11.35 micrograms/100 ml (95% CI = 9.32; 13.82) among a comparable group of children. In addition to blood lead, tooth lead was used to assess exposure among children. Statistically significant differences (p < 0.05) were observed between the geometric mean tooth lead level of 6.44 micrograms Pb/g (n = 13; 95% CI = 3.95; 10.50) in the most contaminated zone and 1.43 micrograms Pb/g (n = 35; 95% CI = 1.11; 1.84) in zones farther away from the point source. Both biomarkers, blood and tooth lead levels, reflect a similar pattern of lead exposure in children. This study has attempted a quantitative assessment of risk factors associated with elevated lead exposure in the Czech Republic. Content of lead in soil, residential distance from the smelter, consumption of locally grown vegetables or fruits, drinking water from local wells, the mother's educational level, cigarette consumption among family members, and the number of children in the family were factors positively related (p < 0.05) to blood lead levels. The resulting blood lead level was found to be inversely proportional to the child's age.
Notes: Environmental Health Perspectives. 105(4)
Journal Article


Author:Heather F. Clark, Daniel J. Brabander and Rachel M. Erdil
Title:Sources, Sinks, and Exposure Pathways of Lead in Urban Garden Soil
Abstract:The chemistry of Pb in urban soil must be understood in order to limit human exposure to Pb in soil and produce and to implement remediation schemes. In inner-city gardens where Pb contamination is prevalent and financial resources are limited, it is critical to identify the variables that control Pb bioavailability. Field-portable X-ray fluorescence was used to measure Pb in 103 urban gardens in Roxbury and Dorchester, MA, and 88% were found to contain Pb above the USEPA reportable limit of 400 mg/kg. Phosphorus, iron, loss on ignition, and pH data were collected, Pb-bearing phases were identified by X-ray diffraction, and Pb isotopes were measured using inductively coupled plasma mass spectrometry. Four test crops were grown both in situ and in Roxbury soil in a greenhouse, and plant tissue was analyzed for Pb uptake by polarized energy-dispersive X-ray fluorescence. Variation at the neighborhood scale in soil mineralogical and chemical characteristics suggests that the bioavailable fraction of Pb in gardens is site specific. Based on Pb isotope analysis, two historical Pb sources appear to dominate the inventory of Pb in Roxbury gardens: leaded gasoline (207 Pb/206 Pb = 0.827) and Pb-based paint (207Pb/206 Pb = 0.867). Nearly 70% of the samples analyzed can be isotopically described by mixing these two end members, with Pb-based paint contributing 40 to 80% of the mass balance. A simplified urban human exposure model suggests that the consumption of produce from urban gardens is equivalent to approximately 10 to 25% of children's daily exposure from tap water. Furthermore, analysis of over 60 samples of plant tissue from the four test species suggests that in these urban gardens unamended phytoremediation is an inadequate tool for decreasing soil Pb.
Notes:J Environ Qual 35:2066-2074 (2006), DOI: 10.2134/jeq2005.0464


Author:Clark S, Menrath W, Chen M, Succop P, Bornschein R, Galke W, Wilson J.
Abstract:To aid in understanding the contribution of exterior dust/soil lead to postintervention interior dust lead, a subset of housing from the HUD Lead-Based Paint Hazard Control Grant Program Evaluation was selected for study. Housing from 12 state and local governments was included. Exterior entry and street dust samples were obtained by a vacuum method, and soil samples were building perimeter core composites. Interior dust wipe lead data (microg/ft(2)) and paint lead data (mg/cm(2)) were also available for each of the dwelling units and included in the modeling. Results from 541 dwelling units revealed a wide range of exterior dust and soil lead levels, within and between grantees. Minimum and maximum geometric mean lead levels, by grantee, were 126 and 14400 microg/ft(2) for exterior entry dust; 325 and 4610 microg/ft(2) for street dust; and, for soil concentration, 383 and 2640 ppm. Geometric mean exterior entry dust lead concentration (1641 ppm) was almost four times as high as street dust lead concentration (431 ppm), suggesting that lead dust near housing was often a source of street dust lead. Geometric mean exterior entry dust lead loading was more than four times as high as window trough dust lead loading and more than an order of magnitude higher than interior entry dust lead loading. Statistical modeling revealed pathways from exterior entry dust lead loading to loadings on interior entryway floors, other interior floors, and windowsills. Paint lead was found to influence exterior entry dust lead. Results of this study show that housing where soil lead hazard control activities had been performed had lower postintervention exterior entry, interior entry floor, windowsills, and other floor dust loading levels. Soil was not present for almost half the buildings. Statistical analysis revealed that exterior strategy influenced soil lead concentration, and soil lead concentration influenced street dust lead loading. This study represents one of the few where an impact of soil treatments on dust lead levels within the housing has been documented and may represent the first where an impact on exterior entry dust lead has been found. The inclusion of measures to mitigate the role of exterior sources in lead hazard control programs needs consideration.
Notes:J Occup Environ Hyg. 2004 May;1(5):273-82.

Author:Culbard E, Thornton I, Watt J, Wheatley, M, Moorcroft S, Thompson M. 1988. Metal contamination in British urban dusts and soils. J Environ Qual 17:226-234.
Abstract:

Reference Type: Journal Article
Record Number: 55
Author: Devey, P.; Jingda, L.
Title: Soil lead levels in parks and playgrounds: an environmental risk assessment in Newcastle
Pages: 189-92, 1995 Apr.
Accession Number: 7786947
Abstract: In June 1993 the National Health and Medical Research Council set a national goal for blood lead of below 10 micrograms/dl. There is a need to know if the lead contamination of the urban environment is so high as to put community health at risk. Decisions, including whether soil should be removed and replaced, will have to be made. During the second half of 1993, an environmental assessment of lead contamination of soil within the City of Newcastle was conducted. Samples, 108 from surface soil and 10 from subsurface soil, were taken from public parks and playgrounds in the city area and analysed for lead content. The proportion within and the proportion above the guidelines for soil contamination were reported. Lead concentrations ranged from 25 to 2400 parts per million (ppm); 21 per cent of samples had concentrations higher than the 300 ppm action level, and the geometric mean was 134 ppm. Both the range and the average lead levels were typically no more than, or were even less than, soil lead levels documented for other cities in Australia, the United States and United Kingdom. Although each sampling site was noted, it was not our intention to focus in on individual sites. Indeed, to draw health-risk implications from any one result may be misleading and inaccurate. The results indicated moderate lead contamination of soil that could be controlled by regular top-dressing of soils, the use of bark chip on playground surfaces and by government initiatives aimed at lowering lead levels in petrol.
Notes: Australian Journal of Public Health. 19(2)
Journal Article



Author: Dixon SL, McLaine P, Kawecki C, Maxfield R, Duran S, Hynes P, Plant T.
Title:The effectiveness of low-cost soil treatments to reduce soil and dust lead hazards: The Boston lead safe yards low cost lead in soil treatment, demonstration and evaluation. Abstract:The Boston lead safe yards low cost lead in soil treatment, demonstration, and evaluation was developed to explore the viability and effectiveness of low-cost soil interventions to reduce exposure to soil lead hazards. Buildings that had been abated for lead to Massachusetts's deleading standards in the previous 5yrs and met other program requirements were recruited for the evaluation. Following individual property assessments, yards were treated with application of ground coverings and ground barriers in 2000-2001 and followed up at 1yr. The treatment cost ranged from $1095 to $5643 with an average of $2798. Soil lead levels at the building dripline, measured with a field-portable X-ray fluorescence analyzer (Niton Model 702 Spectrum Analyzer), dropped from 2021PPM at baseline to 206PPM at 1-yr follow-up. Most of the barrier treatments continued to block access to the lead-contaminated soil at 1yr. At the follow-up, few properties with grass treatment had areas that were completely bare, but 28% had more than a small amount of treated areas bare. Treatments were effective in reducing entryway dust lead in the rear of the building if the residents reported they had maintained the yard treatments. Each additional yard work activity reported was predicted to lower 1-yr floor dust lead loading at the rear common/main and dwelling unit entries by about 20%. Each additional 100ft(2) of yard treated was predicted to lower 1-yr floor dust loading at the rear dwelling unit entry by 19%. Treatments did not show a dust lead effect at 1yr in the front entryway of the building, but the investigators believe that this may be due to the effect of resident cleaning overshadowing the treatment effect. Notes: Environ Res. 2006 Feb 23; [Epub ahead of print]



Author:Duggan MJ.
Title:Contribution of lead in dust to children's blood lead
Abstract:The importance of urban dust as a source of lead for young children is still disputed. Although blood-lead data from various population surveys usually show a peak concentration in early childhood, there is evidence that such a peak is small or absent altogether in children without much access to the general environment. An examination of those studies where groups of people in regions of low and high lead contamination have been compared shows that the child/adult blood-lead ratio is almost always enhanced in the more exposed groups. This implies a route of lead uptake which is important for children but less so for adults, and it is likely that this route is the dust-hand-mouth one. There are sufficient data to suggest a quantitative relationship between raised levels of blood lead and lead in dust. There is a strong case for a lead-in-dust standard but some will probably remain unpersuaded unless or until there are reliable data for blood lead and environmental lead involving matched groups of young people from urban and rural areas.
Source:Environ Health Perspect. 1983 Apr;50:371-81.

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Reference Type: Journal Article
Record Number: 56
Author: Elhelu, M. A.; Caldwell, D. T.; Hirpassa, W. D.
Title: Lead in inner-city soil and its possible contribution to children's blood lead
Pages: 165-9, 1995 Mar-Apr.
Accession Number: 7786053
Abstract: This study was designed to assess distribution and sources of lead in inner-city soils in Washington, D.C. Duplicate soil samples were collected randomly from 239 unpaved front yards of homes in Washington, D.C. Soil samples were collected 1 m from the houses. Lead concentration in soil was determined by flame atomic absorption spectrophotometry. Presence of lead detected in soil was correlated and traced to the anticipated source of origin. A significantly high concentration of lead was present in inner-city soils. Areas of the city in which the highest lead concentrations were found (Wards 1, 4, 5, 6, 7, 8) were determined to contain a large number of residents who had attained lower education levels than most residents in the remaining wards. It was concluded that lead concentration in inner-city soil plays a significant role in the incidence of lead poisoning in children in the District of Columbia and that paint is the main source of soil lead. Demographic characteristics of the residents appeared to enhance the distribution of lead poisoning.
Notes: Archives of Environmental Health. 50(2)
Journal Article


Reference Type: Journal Article
Record Number: 73
Author: Elwood, P. C.
Title: The sources of lead in blood: a critical review
Pages: 1-23, 1986 Jun.
Accession Number: 3523752
Notes: Review
Science of the Total Environment. 52(1-2)
Journal Article


Reference Type: Journal Article
Record Number: 63
Author: Fett, M. J.; Mira, M.; Smith, J.; Alperstein, G.; Causer, J.; Brokenshire, T.; Gulson, B.; Cannata, S.
Title: Community prevalence survey of children's blood lead levels and environmental lead contamination in inner Sydney.[see comment]
Pages: 441-5, 1992 Oct 5.
Accession Number: 1406391
Abstract: OBJECTIVE: To determine the distribution of blood lead levels in preschool children in inner Sydney and identify possible sources of environmental lead. DESIGN: Cross sectional community based prevalence survey of children and the houses in which they live, and a survey of volunteer children. SETTING: Mort Bay and Summer Hill, residential localities in inner Sydney. PARTICIPANTS: Ninety-five children aged 9-48 months able to be identified in a defined geographic area and 63 children aged 9-48 months volunteered by their parents. OUTCOME MEASURES: Concentrations of lead in venous blood of all children and in samples from the home environment of Mort Bay children. RESULTS: Four of the children (2.5%) had blood lead levels > or = 1.21 mumol/L (25 micrograms/dL, the current Australian threshold of concern), 27 (17.1%) had levels > or = 0.72 mumol/L (15 micrograms/dL, the new US threshold for individual intervention) and 80 (50.6%) had levels > or = 0.48 mumol/L (10 micrograms/dL, the new US threshold for community intervention). Blood lead concentrations were significantly correlated with concentrations of lead in "sink" soil (r = 0.555, P = 0.026), play area soil (r = 0.492, P = 0.016) and dust from vacuum cleaners (r = 0.428, P = 0.05), and with age of child (r = -0.182, P = 0.023). The presence of the child during house renovation was a strong predictor of having a blood lead level above 0.72 mumol/L (15 micrograms/dL) (odds ratio, 4.6; 95% confidence interval, 1.8-11.7, P = 0.001). CONCLUSIONS: Lead in soil and in household dust in older areas of Sydney is likely to represent a significant health hazard to young children. Many thousands of children may be affected in Sydney and other Australian cities. There is an urgent need for expanded prevalence surveys, public education and the development of strategies for the abatement of lead in urban environments.
Notes: Medical Journal of Australia. 157(7)
Journal Article

Author: Filippelli, Gabriel M., Laidlaw, Mark A.S,
Title: The Elephant in the Playground: confronting lead-contaminated soils as an important source of lead burdens to urban populations
Reference: Perspectives in Biology and Medicine. volume 53, number 1 (winter 2010):31-45.
abstract: Although significant headway has been made over the past 50 years in understanding and reducing the sources and health risks of lead, the incidence of lead poisoning remains shockingly high in urban regions of the United States.At particular risk are poor people who inhabit the polluted centers of our older cities without the benefits of adequate nutrition, education, and access to health care.To provide a future with fewer environmental and health burdens related to lead,we need to consider the multiple pathways of lead exposure in children, including their continued contact with dust derived from inner-city soils.Recent research into the causes of seasonal variations in blood-lead levels among children has confirmed the importance of soil in lead exposure. Capping lead-contaminated soil with lead-free soil or soil amendment appears to be a simple and cost-effective way to reduce the lead load for urban youth.

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Author Filippelli, Gabriel M., Laidlaw, Mark A.S., Latimer, Jennifer C., Raftis, Robyn Urban Lead Poisoning and Medical Geology: An Unfinished Story GSA Today 2005 15: 4-11
ABSTRACT: The intersection between geological sciences and human health, termed medical geology, is gaining significant interest as we understand more completely coupled biogeochemical systems. An example of a medical geology problem largely considered solved is that of lead (Pb) poisoning. With aggressive removal of the major sources of Pb to the environment, including Pb-based paint, leaded gasoline, and lead pipes and solder, the number of children in the United States affected by Pb poisoning has been reduced by 80%, down to a current level of 2.2%. In contrast to this national average, however, about 15% of urban children exhibit blood Pb levels above what has been deemed safe (10 ug per deciliter); most of these are children of low socioeconomic-status minority groups. We have analyzed the spatial relationship between Pb toxicity and metropolitan roadways in Indianapolis and conclude that Pb contamination in soils adjacent to roadways, the cumulative residue from the combustion of leaded gasoline, is being remobilized. Developing strategies to remove roadway Pb at the source is a matter of public health and social justice, and constitutes perhaps the final chapter in this particular story of medical geology.

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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