Soil Lead (Pb) in New Orleans: A Spatiotemporal and Racial Analysis.

Spatialized racial injustices drive morbidity and mortality inequalities. While many factors contribute to environmental injustices, Pb is particularly insidious, and is associated with cardio-vascular, kidney, and immune dysfunctions and is a leading cause of premature death worldwide. Here, we present a revised analysis from the New Orleans dataset of soil lead (SPb) and children's blood Pb (BPb), which was systematically assembled for 2000-2005 and 2011-2016. We show the spatial-temporal inequities in SPb, children's BPb, racial composition, and household income in New Orleans. Comparing medians for the inner city with outlying areas, soil Pb is 7.5 or 9.3 times greater, children's blood Pb is ~2 times higher, and household income is lower. Between 2000-2005 and 2011-2016, a BPb decline occurred. Long-standing environmental and socioeconomic Pb exposure injustices have positioned Black populations at extreme risk of adverse health consequences. Given the overlapping health outcomes of Pb exposure with co-morbidities for conditions such as COVID-19, we suggest that further investigation be conducted on Pb exposure and pandemic-related mortality rates, particularly among Black populations. Mapping and remediating invisible environmental Pb provides a path forward for preventing future populations from developing a myriad of Pb-related health issues.

Toxicological potential of cobalt in forage for ruminants grown in polluted soil: a health risk assessment from trace metal pollution for livestock.

The trace metal pollution in the environment is a highly concerned issue in these days. One of the important causes of trace metal pollution is the exhaust gases released from the vehicles on the roads. These dangerous gases pose life-threatening effects on the forage plants grown along the roadside as these plants are at direct risk to these trace metals. The aims of the present study were to determine the cobalt (Co) concentrations in soil, forages, and blood plasma of the buffaloes and to evaluate the Co deficiencies and toxicities in these samples. All samples were collected from six sites (Faisalabad roadside, Bhalwal roadside, Shaheenabad roadside, Mateela roadside, 50 Chak roadside, and Dera Saudi-control) of Sargodha city. The Co concentrations in these samples were determined by atomic absorption spectrophotometer (AA-6300 Shimadzu Japan). In soil samples, Co level ranged from 1.958 to 3.457 mg/kg in the six sampling sites. The highest Co level was observed at site 6 and the lowest at site 2. In forage samples, Co level ranged from 0.770 to 2.309 mg/kg in the six sampling sites. The highest Co level was observed at site 3 and the lowest at site 2. In blood plasma samples, Co level ranged from 2.644 to 4.927 mg/kg in the six sampling sites. The highest Co level was observed at site 1 and the lowest at site 3. The results showed higher Co values in the samples collected from the site IV while the bioconcentration factor for forage-soil was found highest in the samples collected from Site III. On the other hand, a correlation was found positively significant when soil and forage were correlated, and it was found negatively significant when blood and forage were correlated.

Comparison of oral bioavailability of benzo[a]pyrene in soils using rat and swine and the implications for human health risk assessment.

BACKGROUND: There are many uncertainties concerning variations in benzo[a]pyrene (B[a]P) soil guidelines protecting human health based on carcinogenic data obtained in animal studies. Although swine is recognised as being much more representative of the human child in terms of body size, gut physiology and genetic profile the rat/mice model is commonly used in practice. OBJECTIVES: We compare B[a]P bioavailability using a rat model to that estimated in a swine model, to investigate the correlation between these two animal models. This may help reduce uncertainty in applying bioavailability to human health risk assessment. METHODS: Twelve spiked soil samples and a spiked silica sand (reference material) were dosed to rats in parallel with a swine study. B[a]P bioavailability was estimated by the area under the plasma B[a]P concentration-time curve (AUC) and faecal excretion as well in the rats. Direct comparison between the two animal models was made for: firstly, relative bioavailability (RB) using AUC assay; and secondly, the two assays in the rat model. RESULTS: Both AUC and faecal excretion assays showed linear dose-response for the reference material. However, absolute bioavailability was significantly higher when using faecal excretion assay (p<0.001). In aged soils faecal excretion estimated based on solvent extraction was not accurate due to the form of non-extractable fraction through ageing. A significant correlation existed between the two models using RB for soil samples (RBrat=0.26RBswine+17.3, R(2)=0.70, p<0.001), despite the regression slope coefficient revealing that the rat model would underestimate RB by about one quarter compared to using swine. CONCLUSIONS: In the comparison employed in this study, an interspecies difference of four in RB using AUC assay was identified between the rat and swine models regarding pharmacokinetic differences, which supported the body weight scaling method recommended by US EPA. Future research should focus on the carcinogenic competency (pharmacodynamics) used in experiment animals and humans.

Human exposure and risk assessment of cadmium for residents of abandoned metal mine areas in Korea.

The objective of this study is to find the Cd levels in agricultural crops compared to soil, to evaluate the relationship between daily intake dose through the multimedia/multi-pathway of human exposure and biomarker levels of the residents in mine vicinity area. We collected and cited the data of four out of ten health impact assessments for the residents of abandoned mine areas undertaken by the Korea Ministry of Environment in 2008. The Cd levels in soil were significantly decreased by the separation distance from the mines. The Cd levels in blood were significantly different between residents in mine areas and in comparative areas, but urinary Cd levels did not differ. The Cd levels in blood were related to the age; the separation distance from mine to residence; the daily intake dose via ingestion of drinking water, crops, and surface soil; and inhalation of ambient air of Cd, but urinary Cd levels were not relevant with various sociodemographic characteristics and exposure factors. The average hazard quotient (HQ) value of Cd in the mining site was below 1.0, but the maximum HQ was closed to 1.0. The results indicated that the ingestion of Cd-contaminated soil and agricultural crops by local inhabitants could pose potential adverse health effects to long-term residents consuming rice grown near to the mining areas.

Evolving from reactive to proactive medicine: community lead (Pb) and clinical disparities in pre- and post-Katrina New Orleans.

In 2012 the U.S. Centers for Disease Control (CDC) set the blood Pb reference value at ≥5 µg/dL. Clinical analysis of children's blood Pb levels is the common way to diagnose environmental Pb contamination, and intervention ensues with education and household dust cleanup. Recent review indicates that education and household dust cleanup are not effective at reducing children's Pb exposure. Here we review mapping environmental Pb and children's blood Pb response as an alternative approach for proactive Pb dust intervention. New Orleans was divided into a high (≥100 mg/kg) and low (<100 mg/kg) soil Pb communities. The children's blood Pb prevalence ≥5 µg/dL for the high and low Pb domains were 58.5% and 24.8% respectively pre-Katrina vs. 29.6% and 7.5% post-Katrina. Elevated soil Pb (mg/kg) and consequently Pb loading (µg/square area) permeates the high Pb domain and outdoor locations lack Pb dust safe play areas. The U.S. EPA 400 mg/kg soil Pb standard poses an outside Pb dust loading burden >37 times larger than allowed on interior residential floor environments. Environmental Pb dust is decreasing because of the transfer of large quantities of low Pb soil into selected communities. City-scale soil Pb mapping is an alternative diagnostic tool that provides information for planning proactive medicine to prevent clinical Pb exposure in the first place.

Spatial relationships between lead sources and children's blood lead levels in the urban center of Indianapolis (USA).

Urban children remain disproportionately at risk of having higher blood lead levels than their suburban counterparts. The Westside Cooperative Organization (WESCO), located in Marion County, Indianapolis, Indiana, has a history of children with high blood lead levels as well as high soil lead (Pb) values. This study aims at determining the spatial relationship between soil Pb sources and children's blood lead levels. Soils have been identified as a source of chronic Pb exposure to children, but the spatial scale of the source-recipient relationship is not well characterized. Neighborhood-wide analysis of soil Pb distribution along with a furnace filter technique for sampling interior Pb accumulation for selected homes (n = 7) in the WESCO community was performed. Blood lead levels for children aged 0-5 years during the period 1999-2008 were collected. The study population's mean blood lead levels were higher than national averages across all ages, race, and gender. Non-Hispanic blacks and those individuals in the Wishard advantage program had the highest proportion of elevated blood lead levels. The results show that while there is not a direct relationship between soil Pb and children's blood lead levels at a spatial scale of ~100 m, resuspension of locally sourced soil is occurring based on the interior Pb accumulation. County-wide, the largest predictor of elevated blood lead levels is the location within the urban core. Variation in soil Pb and blood lead levels on the community level is high and not predicted by housing stock age or income. Race is a strong predictor for blood lead levels in the WESCO community.

Lead exposure assessment from study near a lead-acid battery factory in China.

The production of lead-acid battery in China covered about one-third of the world total output and there are more than 2000 lead-acid battery factories. They may cause the major environment lead pollution. Blood lead levels of several hundreds of residents were over 100 µg/L due to the waste discharges from a lead-acid battery factory in Heyuan, Guangdong province. This study aimed to find out the environmental lead sources, the human lead exposure pathways, and the amplitudes from a lead-acid battery factory. The study results showed that lead levels in soil, dust, tree leaves and human blood declined with the distances increased from the production site. Twenty nine of 32 participants had blood lead levels of over 100 µg/L with an exceptional high value of 639 µg/L for one child. This result suggested that the lead-acid battery production from this factory has caused the elevated lead levels in its neighboring environment and residents. Dust intake was the dominant exposure pathway for humans (over 90%). The lead levels found in adult and toddler (6.19 and 50.1 µg/kg/d, respectively) in the polluted area were far higher than the provisional tolerable weekly intake (PTWI) of 25 µg/kg body weight (translated into 3.5 µg/kg/d), which was established by the joint FAO/WHO Expert Committee. Blood lead levels within the family members were strongly correlated with the house dust lead levels. Our results in this study suggested that further studies in this area should be performed to assess human exposure and relevant human health risks from living close to lead-acid battery factories.

A GIS-aided assessment of the health hazards of cadmium in farm soils in central Taiwan.

A geostatistical method was developed to examine the correlation, or lack of it, between the levels of cadmium (Cd) detected in farm soils and those detected in the human specimens collected from residents around the contaminated areas in Changhua County where cadmium contamination of staple rice has been documented. We used the Taiwan EPA environment data in 2002 and human data which were generated by the National Health Research Institutes during 2003-2005. Kriging interpolation methods were used to determine soil Cd concentrations. A Zonal statistical function was performed to assess the individual exposure. Soil Cd levels and tissue Cd levels in residents were analyzed for contamination hotspots and other areas to determine correlation between the two variables. Three Cd contamination hotspots were identified, in which no correlation was found between soil Cd levels and tissue Cd levels in residents. Our results demonstrate how GIS spatial modeling technique can be used to estimate distribution of pollutants in an area using a limited number of data points. Results indicated no association between the soil contamination and the exposure of residents to Cd, suggesting that both the soils and the residents are receptors of Cd as a pollutant from as yet unidentified sources.

Nonlinear associations between blood lead in children, age of child, and quantity of soil lead in metropolitan New Orleans.

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°·5 significantly increases the BL level in children (b=0.214 p= or <0.01), and a unit change in Age°·5 significantly increases child BL (b=0.401, p= or <0.01). A unit change in Age°·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 BL> 10 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 100mg/kg provides children with substantial economic benefit.

Assessment of polychlorinated biphenyls and mercury levels in soil and biological samples from San Felipe, Nuevo Mercurio, Zacatecas, Mexico.

The aim of this work was to evaluate contamination by polychlorinated biphenyls and mercury in soil, and to assess exposure level to both contaminants in children living in San Felipe, Nuevo Mercurio, Zacatecas, Mexico. We found soil levels of total polychlorinated biphenyls ranging from non detectable (nd) to 190 µg/kg. Mercury soil levels ranged from 8.9 to 10215.0 mg/kg. Exposure levels of total polychlorinated biphenyls assessed in blood and urinary mercury in children living in the studied community were 1,600 ± 8,800 ng/g lipid and 4.2 ± 7.1 µg/g creatinine, respectively.

Exposure assessment at a PCDD/F contaminated site in Sweden--field measurements of exposure media and blood serum analysis.

BACKGROUND, AIM, AND SCOPE: The main pathway for human exposure to the highly toxic polychlorinated-p-dioxins and polychlorinated furans [polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs)] is via dietary intake. Other exposure pathways may, however, be important in close proximity to point sources, such as wood preservation sites, where PCDD/F contaminated chlorophenols (CP) were previously used. In this study, a heavily PCDD/F contaminated CP saw mill site in Sweden was investigated. Human exposure through a broad spectrum of exposure pathways was assessed. Such studies are in demand since the question whether contaminated sites represent a current or future risk can only be answered by detailed site-specific risk assessments. MATERIALS AND METHODS: Sampling of exposure media (soil, air, groundwater, raspberries, carrots, potatoes, grass, milk, eggs, and chicken fodder) was made. Exposure media concentrations and congener distribution patterns were used to investigate the mobilization of PCDD/Fs from soil to the environment and to calculate exposure levels for adults. Blood serum levels from site-exposed and control individuals were also analyzed. RESULTS: Congener distribution patterns at the site were generally dominated by a specific marker congener (1234678-HpCDF), which is highly abundant in the polluted soil. The dioxin toxic equivalents (TEQ) concentrations were notably elevated as compared to national reference samples for most exposure media, and the marker congener was a major contributor to increased TEQ levels. There were also indications of soil-to-air volatilization of tetra- and penta-CDD/Fs. People who participated in the restoration of a contaminated building showed higher levels of 1234678-HpCDF compared to controls, and calculated exposure levels suggest that several site-specific exposure routes may be of importance for the daily intake of PCDD/F. CONCLUSIONS, RECOMMENDATIONS, AND PERSPECTIVES: Despite low mobility of higher chlorinated PCDD/Fs, these contaminants were transferred from the polluted soil to the surroundings and into human tissue. The extent of increased exposure from contaminated sites depends on the PCDD/F source strength of the soil, composition of the pollution, human activities, and dietary patterns of the residents. Impact from the contaminated soil on other exposure media was seen also for areas with low to moderate soil contamination. In the future, not only the levels of PCDD/F soil pollution but also the composition must be considered in risk assessments of contaminated sites.

Pesticide exposure of pregnant women in Guadeloupe: ability of a food frequency questionnaire to estimate blood concentration of chlordecone.

CONTEXT: Chlordecone, an environmentally persistent organochlorine insecticide used intensively in banana culture in the French West Indies until 1993, has permanently polluted soils and contaminated foodstuffs. Consumption of contaminated food is the main source of exposure nowadays. We sought to identify main contributors to blood chlordecone concentration (BCC) and to validate an exposure indicator based on food intakes. MATERIAL AND METHODS: We used a food frequency questionnaire (FFQ) completed by a sample of 194 pregnant women to estimate their dietary exposure to chlordecone and compared it to blood levels. In a first approach, chlordecone daily intake was estimated as the product of daily eaten quantity of 214 foodstuffs, multiplied by their chlordecone content, and summed over all items. We then predicted individual blood chlordecone concentration with empirical weight regression models based on frequency of food consumption, and without contamination data. RESULTS: Among the 191 subjects who had BCC determination, 146 (76%) had detectable values and mean BCC was 0.86 ng/mL (range < LOD-13.2). Mean per capita dietary intake of chlordecone was estimated at 3.3 microg/day (range: 0.1-22.2). Blood chlordecone levels were significantly correlated with food exposure predicted from the empirical weight models (r=0.47, p<0.0001) and, to a lesser extent, with chlordecone intake estimated from food consumption and food contamination data (r=0.20, p=0.007). Main contributors to chlordecone exposure included seafood, root vegetables, and Cucurbitaceous. CONCLUSION: These results show that the Timoun FFQ provides valid estimates of chlordecone exposure. Estimates from empirical weight models correlated better with blood levels of chlordecone than did estimates from the dietary intake assessment.

Lead concentration in the blood of children and its association with lead in soil and ambient air--trends between 1983 and 2000 in Duisburg.

Children are known to be at greater risk of exposure to lead (Pb). As Pb levels in ambient air have decreased during the last decades, the relative contribution of soil ingestion to ambient Pb exposure has increased. Using data from five cross-sectional studies conducted during 1983 to 2000 in the industrial city of Duisburg and comprising 843 children, 6-11 yr old, the aim of this study was to evaluate the contribution of Pb in soil to Pb blood levels of children in comparison to the contribution of Pb in air. Based on measurements of soil samples, the spatial distribution of Pb in soil (0-10 cm depth) was estimated for the study area. Pb exposure in ambient air was calculated using routinely monitored air quality data and Lagrange dispersion modeling. Individual exposure data were assigned using geo-coded home addresses. Multiple linear regression analysis was applied to estimate adjusted association measures. Median (95th percentile) level of Pb in soil was 206 (877) mg/kg. A simultaneous decrease in air Pb and blood Pb was observed (air: from 0.47 (0.47) to 0.03 (0.16) microg/m(3); blood: from 86 (163) to 31 (68) microg/L). Significant associations between Pb in blood and Pb in the two exposure media were found. An increase of 0.44 microg/m(3) Pb in air led to an rise in blood Pb by 155%, whereas blood Pb changed by about 63% if Pb in soil increased by 800 mg/kg. The results of the study were used for a local risk assessment and the definition of action values for Pb in soil.

Comparison of in vivo and in vitro methodologies for the assessment of arsenic bioavailability in contaminated soils.

An in vivo swine assay was utilised for the determination of arsenic (As) bioavailability in contaminated soils. Arsenic bioavailability was assessed using pharmacokinetic analysis encompassing area under the blood plasma-As concentration time curve following zero correction and dose normalisation. In contaminated soil studies, As uptake into systemic circulation was compared to an arsenate oral dose and expressed as relative As bioavailability. Arsenic bioavailability ranged from 6.9+/-5.0% to 74.7+/-11.2% in 12 contaminated soils collected from former railway corridors, dip sites, mine sites and naturally elevated gossan soils. Arsenic bioavailability was generally low in the gossan soils and highest in the railway soils, ranging from 12.1+/-8.5% to 16.4+/-9.1% and 11.2+/-4.7% to 74.7+/-11.2%, respectively. Comparison of in vivo and in vitro (Simplified Bioaccessibility Extraction Test [SBET]) data from the 12 contaminated soils and bioavailability data collected from an As spiked soil study demonstrated that As bioavailability and As bioaccessibility were linearly correlated (in vivo As bioavailability (mgkg(-1))=14.19+0.93.SBET As bioaccessibility (mgkg(-1)); r(2)=0.92). The correlation between the two methods indicates that As bioavailability (in vivo) may be estimated using the less expensive, rapid in vitro chemical extraction method (SBET) to predict As exposure in human health risk assessment.

Assessment of soil lead exposure in children in Shenyang, China.

Soil lead pollution is serious in Shenyang, China. The paper brings together the soil work, the bioaccessibility, and the blood lead data to assess the soil lead exposure in children in Shenyang, China. Approximately 15.25% of the samples were above China Environment Protection Agency guideline concentration for soil Pb to protect human from health risk (350 mgkg(-1)). Pb concentrations varied among use scenarios. The main lead contamination sources are industry emission and automobile exhaust. Bioaccessibility also varied among use scenarios. Children, who ingested soil from industrial area, public parks, kindergarten playground, and commercial area, are more susceptible to soil lead toxicity. The industrial area soil samples presented higher bioaccessibility compared to the other use scenario soil samples contaminated by automobile exhaust. The result also suggested a most significant linear relationship between the level of Pb contamination and the amount of Pb mobilized from soil into ingestion juice. Soil pH seemed to have insignificant influence on bioaccessibility in the present study. Bioaccessibility was mainly controlled by other factors that are not investigated in this study. A linear relationship between children blood lead and soil intestinal bioaccessibility was present in the study. Children who are 4-5 years old are more likely to demonstrate the significant relationship between soil lead bioaccessibility and blood lead as their behaviors place them at greatest risk of soil lead toxicity, and their blood lead levels are more likely to represent recent exposure.

New Orleans soil lead (Pb) cleanup using Mississippi River alluvium: need, feasibility, and cost.

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

PCB contamination from polysulphide sealants in residential areas-exposure and risk assessment.

From the late 1950s to the early 1970s elastic polysulphide sealants were used in outdoor seams between concrete blocks in prefabricated buildings. The sealants contained 5-30% polychlorinated biphenyls (PCBs). Due to the weathering of sealants in general and the replacement of seams with new PCB-free materials in the 1990s, PCBs have drifted to the soil adjacent to buildings. The objectives of this study were to survey PCB contamination in the surroundings of former PCB-containing buildings and to evaluate the risks to human health. Samples from soil, and also from blood serum of residents, were collected to obtain data for exposure assessment. The health risk assessment was based on deterministic and probabilistic calculations for cancer and non-cancer risks. Soil ingestion and dermal contact were considered the main routes of exposure and children the most important exposed group. The mean total PCB concentration was 6.83 mg/kg within 2m of the buildings and 0.52 mg/kg within 3-10 m from of the buildings. The deterministic risk assessment with conservative parameters resulted in lifetime cancer risk estimates on the order of 10(-6)-10(-7). The lifetime average daily dose (LADD) for PCBs was less than 10% of the reference dose (RfD) 0.02 microg/kg day, which is based on immunosupression in monkeys. The LADD corresponding to the total site attributable exposure was less than 10% of the estimated average dietary PCB intake in Finland. Children can, however, in worst cases be exposed to daily doses near the level of the RfD. Low cost measures are recommended to reduce possible exposure of children.

[Risk assessment of soil contamination in a residential area: the importance and role of human biological monitoring--a case report]. / Gefährdungsabschätzung von Bodenverunreinigungen in einem belasteten Wohngebiet: Bedeutung und Funktion des Human-Biomonitoring -- ein Fallbeispiel.

BACKGROUND AND PURPOSE: High levels of arsenic, cadmium, mercury and polychlorinated dibenzodioxins and dibenzofuranes (PCDD/PCDF) were detected in the soil of a residential area located at the river Elbe near Hamburg (Germany). Soil contamination resulted from sediments from the Hamburg harbour and from the Elbe that were deposited in this area up to the late 1950ies. The objective of this study was to evaluate whether the soil contamination in this area is associated with increased levels of arsenic, heavy metals and PCCD/PCDF in the blood and urine of selected residents living on highly contaminated grounds. RESULTS: The blood levels of lead and PCDD/PCDF and the urine levels of arsenic, cadmium and mercury that were measured in 29 residents living on highly contaminated grounds were not elevated in relation to a control group. All individual values were in the range of the background exposure levels of the general population. There were no signs of an increased additional exposure related to soil contamination. CONCLUSIONS: Based on the results of this study it was agreed to refrain from an expensive redevelopment of this area. As a preventive measure some recommendations were given to the residents to minimize possible exposure to soil contaminants. Human biological monitoring studies should be an essential part of exposure and risk assessment of soil contaminations in residential areas in future studies and as a basis for adequate risk management.

Derivation of a target concentration of Pb in soil based on elevation of adult blood pressure.

The increase in systolic blood pressure in males appears to be the most sensitive adult endpoint appropriate for deriving a health risk-based target level of lead (Pb) in soil. Because the response of blood pressure to blood Pb concentration (PbB) has no apparent threshold, traditional approaches based on the application of a Reference Dose (RfD) are not applicable. An alternative approach is presented based on a model which predicts the population shift in systolic blood pressure from ingestion of Pb contaminated soil as a simultaneous function of exposure to Pb in soil, the baseline distribution of blood Pb concentration in the population and baseline distribution of systolic pressure in the population. This model is analyzed using Monte Carlo analysis to predict the population distribution of systolic pressure resulting from Pb exposure. Based on this analysis, it is predicted that for adult males 18-65 years old, exposure to 1000 ppm Pb in soil will result in an increase of approximately 1 mm Hg systolic pressure, an increase in the incidence of systolic hypertension (i.e., systolic pressure > 140 mm Hg) of approximately 1% and an increase in PbB of 1-3 micrograms/dl. Based on the proposition that these adverse effects can be considered de minimis, 1000 ppm Pb in soil is proposed as a target soil concentration for adult exposure. Available data do not appear to be adequate to predict the newborn PbB level which would result from exposure to this soil level during pregnancy.