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The effect of traffic load on the spatial distribution of lead concentrations in the soil at roadsides and on traffic islands was investigated along a road in Rishon LeZion, Israel. The road comprised two segments that were used during different periods: old, which was in use since 1980; and new, which was opened to traffic in 2004. Soil samples were collected from the upper 0–2 cm soil layer from the roadsides at various distances from the road, and from beneath and between shrubs on the traffic islands. The soil sampling was conducted in 2007 — a few years after the implementation of lead-free fuel — and in 2012. For each soil sample, lead concentration and soil properties associated with lead adsorption (soil organic matter and soil texture) were determined. The amounts of lead around the old road segment were higher than those around the new one. In both sampling years, the lead concentrations at the sides of both road segments were far below the maximum permissible levels for urban and agricultural areas. However, some of the sampling points on the traffic islands of the old road showed lead contamination. Small, non-significant differences in soil lead levels were found at differing distances from the road. Lead-concentration depletion rates of about 1–7 mg kg−1 yr−1 were indicated. Within the traffic islands, the samples collected beneath shrubs contained higher lead concentrations than those collected between shrubs. Soil organic matter levels of

Historic industrial activity led to extensive lead and arsenic contamination within residential areas of East Chicago, Indiana, United States. Although remediation is underway, community concerns about this contamination remain. Therefore, the goal for this analysis was to characterize environmental contamination in soil within and around these areas. A total of 228 samples from 32 different sites (addresses) were collected by community members or study staff. These were analyzed for metals using portable x-ray fluorescence or inductively coupled plasma optical emission spectroscopy. Concentrations exceeding EPA screening levels were found for 42% of the soil arsenic samples, 35% of the soil lead samples, and 79% of the soil manganese samples; a few samples also contained elevated copper or zinc. Concentrations above EPA screening levels were identified both within and outside of the formally designated contaminated area. Roughly 30% of all sites had at least one sample above and one sample below the screening level for arsenic, lead, and manganese. For sites within the contaminated area, more than 90% (arsenic), 60% (lead) and 60% (manganese) of the samples exceeded EPA screening levels. There was a significant association of proximity to the historic industrial site with elevated soil concentrations of arsenic and lead; a similar association was present for manganese. These results are consistent with existing data for lead and arsenic and we additionally report elevated concentrations of manganese and a high within-site variability of all metal concentrations. These findings should be considered in future remediation efforts.

Urban soils in many communities in the United States and internationally have been contaminated by lead (Pb) from past use of lead additives in gasoline, deterioration of exterior paint, emissions from Pb smelters and battery recycling and other industries. Exposure to Pb in soil and related dust is widespread in many inner city areas. Up to 20–40% of urban children in some neighborhoods have blood lead levels (BLLs) equal to or above 5 μg per decilitre, the reference level of health concern by the U.S. Centers for Disease Control. Given the widespread nature of Pb contamination in urban soils it has proven a challenge to reduce exposure. In order to prevent this exposure, an evidence-based approach is required to isolate or remediate the soils and prevent children and adult's ongoing exposure. To date, the majority of community soil Pb remediation efforts have been focused in mining towns or in discrete neighborhoods where Pb smelters have impacted communities. These efforts have usually entailed very expensive dig and dump soil Pb remediation techniques, funded by the point source polluters. Remediating widespread non-point source urban soil contamination using this approach is neither economical nor feasible from a practical standpoint. Despite the need to remediate/isolate urban soils in inner city areas, no deliberate, large scale, cost effective Pb remediation schemes have been implemented to isolate inner city soils impacted from sources other than mines and smelters. However, a city-wide natural experiment of flooding in New Orleans by Hurricane Katrina demonstrated that declines in soil Pb resulted in major BLL reductions. Also a growing body of literature of smaller scale pilot studies and programs does exist regarding low cost efforts to isolate Pb contaminated urban soils. This paper reviews the literature regarding the effectiveness of soil Pb remediation for reducing Pb exposure and BLL in children, and suggests best practices for addressing the epidemics of low-level Pb poisoning occurring in many inner city areas.

Lead is a well-known toxicant associated with numerous chronic diseases. Curtailing industrial emissions, leaded paint, lead in food, and banning highway use of leaded gasoline effectively decreased children's exposure. In New Orleans, irrespective of Hurricane Katrina flooding, lead declined concurrently in topsoil and children's blood. We postulate that topsoil lead and blood lead decreases are associated and common in U.S. cities. This study tests that concept. A small 2002 soil lead survey of 8 Detroit Tri-County Area census tracts was repeated in October 2019. Between 2002 and 2019, Detroit median soil lead decreased from 183 to 92 mg/kg (or 5.4 mg/kg/yr.) and declined in Pontiac from 93 to 68 mg/kg (or 1.4 mg/kg/yr.). Median soil lead remained ~10 mg/kg in outlying communities. Median soil lead (in mg/kg) in communities at 21 km compared to ≥ 21 km from central Detroit, respectively, decreased from 183 to 33 (P-value 10

Background: The contribution of lead contaminated soil to blood lead, especially as it is a large reservoir of lead dust, has been underestimated relative to lead-based paint. On 29 August 2005 Hurricane Katrina flooded and disrupted habitation in New Orleans. Soil and blood lead were mapped prior to Katrina. This unique study addresses soil and blood lead conditions pre- and ten years post-Katrina and considers the effectiveness of low lead soil for lead exposure intervention. Objectives: Comparison of soil and blood lead levels pre- and ten years post-Katrina to evaluate and assess the impact of flooding on soil and blood lead at the scale of the city of New Orleans. Methods: Post-Katrina soil and blood lead data were stratified by the same census tracts (n = 176) as pre-Katrina data. This unique city scale data-set includes soil lead (n = 3314 and 3320, pre- vs. post-Katrina), blood lead (n = 39,620 and 17,739, pre- vs. post-Katrina), distance, and changes in percent pre-1940 housing. Statistical analysis entailed permutation procedures and Fisher's Exact Tests. Results: Pre- vs. ten years post-Katrina soil lead median decreased from 280 mg/kg to 132 mg/kg, median blood lead decreased from 5 μg/dL to 1.8 μg/dL, respectively. Percent pre-1940 housing did not change significantly (P-value = 0.674). Soil and blood lead decrease with distance from the center of New Orleans. Except for age-of-housing results, P-values were extremely small (

Background: Primitive electronic waste (e-waste) recycling creates exposures to several hazardous substances including lead. In Uruguay, primitive recycling procedures are a significant source of lead exposure. Objectives: The aim of this study was to examine lead exposure in blood lead levels (BLLs) in low-income children exposed to lead through burning cables. Methods: A sample of children and adolescents exposed to lead through burning cable activities were assessed at the Department of Toxicology in Montevideo, Uruguay, between 2010 and 2014. Soil lead levels of residences were taken shortly after their assessment. Findings: The final sample included 69 children and adolescents (mean age 7.89 years). More than 66% of participants had an additional source of lead exposure—manual gathering of metals—and medical intervention. Future research should focus on exploring effective interventions to reduce lead exposure among this vulnerable group.

Urban environments are the major sites for human habitation and this study evaluates soil lead (Pb) and blood Pb at the community scale of a U.S. city. There is no safe level of Pb exposure for humans and novel primary Pb prevention strategies are requisite to mitigate children's Pb exposure and health disparities observed in major cities. We produced a rich source of environmental and Pb exposure data for metropolitan New Orleans by combining a large soil Pb database (n=5467) with blood Pb databases (n=55,551 pre-Katrina and 7384 post-Katrina) from the Louisiana Childhood Lead Poisoning Prevention Program (LACLPPP). Reanalysis of pre- and post-Hurricane Katrina soil samples indicates relatively unchanged soil Pb. The objective was to evaluate the New Orleans soil Pb and blood Pb database for basic information about conditions that may merit innovative ways to pursue primary Pb exposure prevention. The city was divided into high (median census tract soil≥100 mg/kg) and low Pb areas (median census tract soil

As urban agriculture grows in popularity throughout North America, vacant lots, underutilized parks, and other open spaces are becoming prime targets for food production. In many post-industrial landscapes and in neighborhoods with a high density of old housing stock, the risk of lead (Pb) contamination at such sites is raising concerns. This paper evaluates the extent to which soil Pb contamination may be an obstacle to the expansion of urban agriculture in Oakland, California. Using a combination of soil sampling at 112 sites, GIS, “hot spot” analysis, and reconstructed land use histories, the research reveals that soil Pb concentrations are generally lower than federal screening levels of 400 ppm, but significantly higher in West Oakland, the city's oldest area and home to a predominantly low-income and African American population. Lead levels are significantly lower in the affluent, predominantly white Oakland hills. Spatial analysis at city- and neighborhood-scales reveals clusters of Pb contamination related to land use history. Site-scale analyses at 12 sites reveals a high level of variability (in some cases related to land use history) that must be taken into consideration when planning for urban agriculture.

Background: Compared with a maximum collective lead (Pb) estimate of � 1811 metric tons (MT) in exterior paint on 86,000 New Orleans houses, Pb additives in gasoline were estimated at � 12,000 MT in New Orleans, yielding � 9100 MT Pb exhausted as aerosols from vehicles; � 4850 MT were particles 410 mm and � 4200 MT were particles o 0.25 mm. Objectives: To evaluate pre-Hurricane Katrina soil Pb and children’s blood Pb at public housing and private residential properties in the inner-city compared with the outer city of New Orleans. Methods: This study includes 224 soil samples from 10 public housing properties and 363 soil samples from residential private properties within an 800 m radius of centroids of public housing census tracts. The Louisiana Childhood Lead Poisoning Prevention Program data from 2000 to 2005 (pre-Hurricane Katrina) was the source for 9807 children’s blood Pb (mg/dL) results. Soil and blood Pb data were grouped by public housing census tracts and private residential properties. This study uses MultiResponse Permutation Procedures for statistical analysis. Results: Brick public properties in the city core had significantly more soil Pb contamination and higher prevalence of elevated children’s blood Pb than same-aged brick public properties in the outer areas of the city. The pre-Hurricane Katrina New Orleans concentration of Pb dust in the inner-city soil displayed a median of 438 mg/kg or 3.7 times larger than Pb dust in outlying areas where the median soil Pb was 117 mg/kg (p-value ¼ 2.9 � 10 � 15 ). Also, the pre-Hurricane Katrina prevalence of children’s blood Pb Z 10 mg/dL was 22.9% within the inner-city compared with 9.1% in the outer areas of New Orleans (p-value ¼3.4 � 10 � 74 ). Conclusions: Comparing the quantities of Pb dust from paint and Pb additives to gasoline, this study supports the later source as a more plausible explanation for the differences in soil Pb and children’s blood Pb within public and private housing in the higher traffic congested inner-city core compared with the lower traffic congested outer areas of New Orleans. Similar patterns of environmental Pb dust contamination and childhood Pb exposure are expected in all cities.

article i nfo Previous studies identified a curvilinear association between aggregated blood lead (BL) and soil lead (SL) data in New Orleans census tracts. In this study we investigate the relationships between SL (mg/kg), age of child, and BL (μg/dL) of 55,551 children in 280 census tracts in metropolitan New Orleans, 2000 to 2005. Analyses include random effects regression models predicting BL levels of children (μg/dL) and random effects logistic regression models predicting the odds of BL in children exceeding 15, 10, 7, 5, and 3 μg/dL as a function of age and SL exposure. Economic benefits of SL reduction scenarios are estimated. A unit raise in median SL 0.5 significantly increases the BL level in children (b=0.214 p=b0.01), and a unit change in Age 0.5 significantly increases child BL (b=0.401, p=b0.01). A unit change in Age 0.5 increases the odds of a child BL exceeding 10 μg/dL by a multiplicative factor of 1.23 (95% CI 1.21 to 1.25), and a unit (mg/kg) addition of SL increases the odds of child BLN10 μg/dL by a factor of 1.13 (95% CI 1.12 to 1.14). Extrapolating from regression results, we find that a shift in SL regulatory standard from 400 to 100 mg/kg provides each child with an economic benefit ranging from $4710 to $12,624 ($US 2000). Children's BL is a curvilinear function of both age and level of exposure to neighborhood SL. Therefore, a change in SL regulatory standard from 400 to 100 mg/kg provides children with substantial economic benefit. Published by Elsevier B.V.

Lead (Pb) poisoning causes permanent neurologic and developmental disorders and remains an important environmental health problem for US children, despite removal of Pb from gasoline and household paints. To better understand the contribution of Pb from historical traffic and residential Pb based paint to soil Pb concentrations in Los Angeles, we analyzed 550 soil Pb samples from south central Los Angeles County, CA, in relation to land-use patterns (commercial, industrial, residential, and parks and open areas) and proximity to freeways, highways, and major arterials. House age variables (surrogates of historical Pb-based paint) and traffic index variables (surrogates of historical traffic) were created at different buffer distances (10–5000 m). Total and bioavailable Pb concentrations near freeways and major arterials were significantly higher than those collected elsewhere. Total and bioavailable Pb concentrations were highly correlated ( r =0.96) after the removal of one outlier. Both parcel-age related variables and traffic variables were important predictors of current soil bioavailable Pb concentrations. Average age of parcels within 30 m and length of small streets within 3000 m explained 57% and 38% of the variance, respectively, in soil bioavailable Pb concentrations in residential areas away from freeways and major arterials ( N =44). Road length of freeways within 750 m explained 28% of bioavailable Pb concentrations in parks and open areas ( N =26). Multi-variable regression models predicted 16–61% of the variances in bioavailable Pb concentrations, depending on land-use type and spatial relationship to roadways. Based on these models a map of spatial distributions of soil Pb concentrations was created for the Los Angeles area that shows promise as a screening tool to evaluate continued Pb poisoning in children.

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.

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, P0.001), 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.

This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150,000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r = 0.91, P < 0.005 for soil lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

A study was conducted in the Makati area of Metro Manila, the Philippines. The study evaluated the significance of playground soil lead intake to the total daily lead burden in preschool children. The lead concentration was measured in residential playground soils, food, water, and hair samples by atomic absorption spectrometer and the data were used to draw conclusions. All of the playground soils were contaminated with lead levels ranging from a minimum of 34.54 microg/g to a maximum of 283.13 microg/g in comparison to the naturally occurring lead level of 15 microg/g in soils. Further, the study conducted a lead analysis on the hair of the study population to determine the accumulated lead intake. Ingestion of 25 mg/day of soil contributed to 4% of the total lead intake per day by children exposed to the study sites. Food (83%) was found to be the major source of lead compared to other sources. The study also includes economic valuation and cost benefit analysis from reducing lead in gasoline.

Lead-contaminated water, soil, and paint have been recognized as potential sources of children's lead exposure for decades, but their contributions to lead intake among urban children remain poorly defined. This analysis was undertaken to estimate the relationship of environmental lead exposures to lead intake among a random sample of urban children, adjusted for exposure to lead-contaminated house dust. Analyses of 183 urban children enrolled in a random sample, cross sectional study were conducted. Children's blood and multiple measures of household dust, water, soil, and paint were analyzed for lead, and interviews were conducted to ascertain risk factors for childhood lead exposure. Environmental sources of lead, including house-dust, soil lead, and water lead, were independently associated with children's blood lead levels. In contrast, paint lead levels did not have a significant effect on blood lead levels after adjusting for other environmental exposures. An increase in water lead concentration from background levels to 0.015 mg/L, the current EPA water lead standard, was associated with an increase of 13.7% in the percentage of children estimated to have a blood lead concentration exceeding 10 micrograms/dL; increasing soil lead concentration from background to 400 micrograms/g was estimated to produce an increase of 11.6% in the percentage of children estimated to have a blood lead level exceeding 10 micrograms/dL, and increasing dust lead loading from background to 200 micrograms/ft2 is estimated to produce an increase of 23.3% in the percentage of children estimated to have a blood lead level exceeding 10 micrograms/dL. These data support the promulgation of health-based standards for lead-contaminated dust and soil and the progressive lowering of standards for lead-contaminated water as the definition of undue lead exposure has been modified.

The concentrations of Pb and Cd were studied in the plant species Pittosporum sinensis (Mock-orange) and Nerium oleander (Oleander) and in the soil of two major parks of Athens. The composition and the density of vegetation differs remarkably in the two parks. The concentrations of both metals were considerably higher at the peripheral zones and decreased towards the interior of the parks. At a distance of 60 m from the periphery to central zones the values almost reached background levels. The degree of plant and soil contamination was well correlated to the density and the structure of vegetation, the traffic volumes, the nature of the leaf surface of the two plants and the wind velocity.

We investigated the validity of dogs and cats as sentinels of environmental lead exposure to humans. This paper reports findings from a study conducted in Granite City, IL, during the summer of 1991. At this site, a former secondary lead smelter had been in activity for more than 80 years. The smelter was shut down in 1982. The surrounding area was found to be contaminated with lead, with soil lead concentrations above 5000 ppm in some places. The Illinois Department of Public Health conducted a survey in the community to determine the effects of lead on the local population. We sampled dogs and cats owned by these people. Our results suggest that living near a closed lead smelter, with heavy soil contamination, was not associated with high blood lead concentrations in pets, or their owners. There was a significant relationship between BLC (blood lead concentrations), in indoor pets and younger children, which was consistent with our hypothesis that pets could be used to monitor childhood lead exposure. We also found that, when there was one pet with a high BLC in a house, the likelihood of finding one person with a BLC above 10 micrograms/dl was significantly increased.

Soil Pb concentration data from the driplines of ancient Danish church roofs have provided a unique 800-year test of a contaminant transport model (SCEMR1) developed to predict the migration of heavy metals and radionuclides in soil. The model's performance in reproducing an 800-year accumulation of Pb in the soil around the church demonstrates the usefulness of simple transport models to assess the consequences of hazardous material, such as lead from industrial activities and even radionuclides from geological disposal of nuclear fuel waste, over hundreds of years. This study demonstrates that the model can be employed for detective work concerning human activities centuries ago and can also predict when a soil profile will reach its contaminant loading potential and pose a groundwater quality threat.

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.

Lead has been recognized for years as an environmental pollutant of concern for young children. Nonetheless, many children in the United States still experience high body burdens of lead. Reducing exposure to lead must include an assessment of all potential sources of lead and a definition of routes of exposure. In this paper, the relationships between soil lead and blood lead concentrations in residents in communities with high soil lead concentrations resulting from past mining and ore processing (milling) activities are compared to those derived from studies in urban communities or communities with operating smelters. The impact of mine waste-derived lead in soil (usually in the form of lead sulfide) on blood lead is less than that for lead in soil derived from smelter, vehicle, or paint sources. Possible reasons for a reduced impact of lead sulfide on blood lead in children in mining communities include the following: lead from mining sources contributes less to lead in the immediate environment of children than lead from other sources; mine wastes typically are of larger particle size, which decreases the bioavailability of lead in the gastrointestinal tract; and lead sulfide is absorbed less in the gastrointestinal tract compared to other lead species. A reduced impact of mine waste-derived lead on blood lead may be important from a regulatory point of view. Expensive cleanup actions for lead-contaminated soils in mining communities based on acceptable soil lead concentrations derived from smelter or urban communities may be questionable in terms of reducing blood lead in children.

This pilot study presents findings of a case study of the prevalence of hyperactive behavior among school children and soil lead concentrations in the urban environment of Ottawa, Canada. Preexisting data on the prevalence of hyperactivity were correlated with soil lead concentrations from soil samples collected in 1981. Soil lead concentrations of the samples were analyzed using atomic absorption spectrometry. Further, synagraphic mapping was done to facilitate spatial analyses of the topographical patterning of the prevalence of hyperactivity and soil lead concentrations. The two major trends in the prevalence of hyperactivity and soil lead data are overlapped and seen as topographical “ridges” running northeast – southwest in the central part of the city. Both trends are geographically bounded and parallel to the major thoroughfares of the city. The explained variability in prevalence of hyperactivity based on soil lead concentrations is 25% in areas of high concordance between the residence of the children and location of the sampling points. The results illustrate the effectiveness of soil lead as a significant indicator of the psychological effect of hyperactivity among urban children, and its importance as a monitor of ambient lead.

Forested residual open spaces are a unique resource that contribute to the diversity of urban ecosystems. Five forested sites located along the Palisades escarpment in New Jersey were selected for a study of tree species distribution, abundance and diversity. Significant correlations existed between these parameters and a number of selected environmental characteristics, including site size and distance from nearest roadway, soil lead and sodium concentrations and surrounding population density. A number of planning and management strategies and considerations for these sites are discussed.

An interlaboratory survey, involving 22 participants, showed generally good intralaboratory precision, but poorer interlaboratory correlation. The most common procedure used mineral acid digestion followed by flame atomic absorption spectrometry. It was found that data obtained by different laboratories can be compared provided that (i)similar analytical procedures are followed and (ii) regular interlaboratory comparison studies take place in order to ensure that systematic interlaboratory differences will not occur.

Lead concentrations were measured in 41 rib samples from the Romano-British cemetery at Poundbury and in two sets of soil samples from the graves yielding up the bones. The levels of lead in the soil were in no way exceptional (means for the two series were 16·7 and 24·8 μg/g dry weight) and there was no correlation between soil lead and bone lead concentrations. Since bone lead concentrations vary independently of those in the soil, it is unlikely that the bones are contaminated by lead in the soil, at least under the conditions prevailing at this particular site.

The levels of lead in city street dirt and in soil from various locations in Glasgow were investigated during spring 1976. Lead concentrations in street dirt ranged from 150–2300 ppm, mean 960 ppm, and were significantly elevated with respect to the observed “natural” level of 78 ppm. Lead derived from anti-knock compounds in petrol and introduced to the environment via automobile exhausts was clearly implicated as the main source of lead pollution in a series of soil lead measurements at the centre and periphery of eight Glasgow parks. Various chemical leaching techniques were employed and compared. Less than 5% of street dirt and soil lead was found to be associated with the organic phase.

Lead concentrations were measured in housedust, pavement dust, road dust and garden soil in and around 97 inner-city houses in Birmingham, England. The highest mean dust lead concentration within the home, 615 micrograms g-1, was noted in samples from under the doormat. Generally, the housedust lead levels were lower than the national mean (507 micrograms g-1), although soil lead concentrations were slightly higher. The age of the property was found to influence the lead levels in both housedust and garden soil, with older houses (greater than 35 years) having significantly higher concentrations than newer properties (less than 35 years). Houses being decorated at the time of sampling were found to have significantly higher lead concentrations than those that were not. Elevated lead levels were also noted in housedust and garden soil from houses located within a 500 m radius of commercial garages. Increased lead concentrations were found in soil samples from gardens in close proximity to waste land (demolition sites and tips), metal-using industries and from those within 10 m of a road. Road dust samples from industrial areas had significantly higher lead concentrations than those from residential areas.

This study uses soil lead as a means of describing the urban lead levels in the metropolitan area of the Twin Cities, and assesses the soil lead levels next to homes of neighborhoods of the metropolitan area. Lead levels of rural soils are around 5 micrograms/g. Near the city limits they increase to 25-50 micrograms/g, and in the central business district they are around 500 to 1000 micrograms/g, or over 100 times greater than in the rural areas. Many Hmong children are suffering from undue lead absorption. The homes of the Hmong children were all located in inner-city neighborhoods. Soil around these homes was compared to soils around homes of a neighborhood away from the inner city. Fifty percent of the Hmong children with lead poisoning inhabit homes which have soil lead levels of 500-999 micrograms/g and 40% live in homes with lead levels of 1000 micrograms/g or more. One home of ten in the outer city has soil lead levels above 500 micrograms/g. The lead sources of the inner city include house paint and leaded gasoline from vehicle traffic. Raising children in high lead environments as found in the Minneapolis inner city has long-term implications because of mental and behavioral deficits that are known to result from chronic exposure to lead.