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In low- and middle-income countries (LMICs), the presence of an informal economy can lead to human exposure to toxic metals such as lead (Pb). This paper demonstrates the local health and economic benefits of modifying practices within the informal economic sector in Madagascar. Specifically, leaded components in 504 locally manufactured household water pumps were replaced with unleaded components. Prior to the intervention, 32% of the household systems exhibited lead concentrations above the World Health Organization (WHO) provisional drinking water guideline of 10 μg/L, but after the intervention, fewer than 3% of the systems were in exceedance. The reduction of lead concentration is modeled to reduce the fraction of children with elevated BLLs (>5 μg/dL) from 34 to 13%. The reduction in BLLs is estimated to provide an average economic benefit of US$11 800 per child based on predicted increases in lifetime productivity. This corresponds to a total benefit of US$8.7 million for the 730 children aged 1-5 associated with the pumps, representing a return on investment of greater than 1000-to-1. Results demonstrate how the formation of partnerships between public, private, and civil society entities, as suggested by UN Sustainable Development Goal 17, can realize important local economic and health benefits in LMICs.

The Meza Valley, Slovenia, has been contaminated by Pb smelting, resulting in an epidemic of lead poisoning in childhood. The potential of remediation with EDTA soil washing to mitigate the risk from Pb poisoning was investigated by applying the Integrated Exposure Uptake Bio-kinetic (IEUBK) model. Soils from 79 locations were collected and the total and bio-accessible Pb concentrations were determined before and after extraction with 60 mmol kg(-1) EDTA. Extraction reduced the soil Pb concentration in towns of Mezica, Zerjav and Crna by 53, 67 and 62%, respectively, and the concentration of in vitro bio-accessible Pb in the simulated human gastric phase by 2.6-, 3.2- and 2.9-times, respectively. The predictions of the IEUBK model based on Pb contamination data were verified with data on blood Pb levels in children. The IEUBK model predicted that, after soil remediation, the number of locations at which the expected blood Pb level in children was higher than the stipulated 10 μg d L(-1) would decrease by 90, 38 and 91% in the towns of Mezica, Zerjav and Crna, respectively. The results confirmed the feasibility of soil washing with EDTA as an efficient remediation measure in Mezica and Crna and advice for soil capping/removal for the most polluted town of Zerjav., (Copyright © 2015 Elsevier B.V. All rights reserved.)

This work aims at illustrating the benefit of combining lead (Pb) biomonitoring data with toxicokinetic simulations in order to confidently identify the risk management intervention that favors the greatest reduction of blood Pb level (BLL) in children exposed to smelter emissions in a mining city from northern Quebec, Canada. The U.S. EPA's Integrated Exposure and Uptake BioKinetic (IEUBK) model was parametrized with relevant environmental concentrations data to simulate background BLL (in average Canadian children) and local BLL (in children from the concerned community). The resulting simulations were compared with corresponding BLL biomonitoring data. Next, soil and air concentrations were lowered sequentially within the IEUBK model to values specified in Quebec's environmental regulations. IEUBK simulations predicted mean BLL values that were similar to the measured biomonitoring values, for both the background (predicted: 0.56 vs observed: 0.5 µg/dL) and local BLL (1.24 vs 1.16 µg/dL). Repeating local BLL simulations with lower Pb concentration in the air or soil based on regulatory guidelines showed a much stronger impact of decreasing soil Pb as compared to air Pb. Concluding, this work shows that soil remediation should be prioritized to lower local children's BLL. Also, the combined use of case-specific environmental Pb levels and biomonitoring data can increase the level of confidence toward an IEUBK-driven identification of the most effective measure for lowering children's BLLs, in the ≤2 µg/dL domain. [ABSTRACT FROM AUTHOR]

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Over centuries the mining industry has been accumulating a great quantity of wastes. The main potentially toxic elements present in the mining wastes are metals and metalloids. Due to its effects on human health, lead is one of the metals in wastes of more concern. Children are the most vulnerable to inorganic‐Pb exposure, due to their behavior and physiology. Therefore, the objective of this research was to determinate lead concentration and dispersion in an inhabited area, also to estimate the risk for children population in the site through the model IEUBK (Integrated Exposure Uptake Biokinetic model). The inorganic lead in dust present in the inhabited area was analytically determined. The risk assessment of lead exposure for children, predicted that is a probability from 31.68 to 90.61% of have lead in blood above of 10 μg dL−1. Remediation actions are recommended in order to mitigate the population exposure. A risk assessment is an important research tool to evaluate the level of population exposure to contaminant sources that can be dangerous for its health and quality of life. This research is significant due to the fact that tailing damps are multicontaminated wastes; moreover Pb is a pollutant that can generate harsh effects in people, especially in children. The lack of urban planning and awareness encouraged that settlements with new families were developed next to tailing damps without concern about the inhabitant's exposure to Pb and other metals. This manuscript proposes the use of models like the IEUBK, as a tool for risk assessment and studies related with urban planning in mining sites. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 391–398, 2018 [ABSTRACT FROM AUTHOR]

The relationships between two exposure media, garden soil and house dust, were studied for Pb uptake in Stratoni village in northern Greece, an industrial area of mining and processing of sulphide ore. Lead data for the two media were assessed in terms of total and bioaccessible content, measurement and geochemical variability, and mineralogical composition. It was found that total Pb was enriched in house dust samples by a factor of 2 on average. Total Pb concentration in soil samples had a maximum of 2,040 mg/kg and reached a maximum of 7,000 mg/kg in house dust samples. The estimated variability due to measurement uncertainty was dominated by the sampling process, and the proportion of sampling variance was greater for soil samples, indicating a higher degree of Pb heterogeneity in soil on the given spatial scale of sampling strata. Although the same general spatial trend was observed for both sampling media with decreasing Pb concentration by increasing distance from the ore-processing plant, Pb in dust samples displayed the highest concentrations within a 300-600-m zone from the ore-processing facility. The significant differences which were observed in Pb speciation between the studied media were explained by differences in mineralogical composition of outdoor soil and indoor dust. Lead-enriched Fe and Mn oxides predominated in soil samples while fine galena grains (<10-20 μm diameter) were the major Pb-bearing phase in dust samples. The integrated exposure uptake biokinetic model was used to predict the risk of elevated blood lead levels in children of Stratoni. Model prediction indicated an average probability of 61 % for blood-Pb to exceed 10 μg/dl. The results underline the importance of house dust in risk assessment and highlight the effect of outdoor and indoor conditions on the fate of Pb in the particular environment of Stratoni. [ABSTRACT FROM AUTHOR]

Lead from historical mining and mineral processing activities may pose potential human health risks if materials with high concentrations of bioavailable lead minerals are released to the environment. Since the Joint Expert Committee on Food Additives of Food and Agriculture Organization/World Health Organization withdrew the Provisional Tolerable Weekly Intake of lead in 2011, an alternative method was required for lead exposure assessment. This study evaluated the potential lead hazard to young children (0–7 years) from a historical mining location at a semi-arid area using the U.S. EPA Integrated Exposure Uptake Biokinetic (IEUBK) Model, with selected site-specific input data. This study assessed lead exposure via the inhalation pathway for children living in a location affected by lead mining activities and with specific reference to semi-arid conditions and made comparison with the ingestion pathway by using the physiologically based extraction test for gastro-intestinal simulation. Sensitivity analysis for major IEUBK input parameters was conducted. Three groups of input parameters were classified according to the results of predicted blood concentrations. The modelled lead absorption attributed to the inhalation route was lower than 2 % (mean ± SE, 0.9 % ± 0.1 %) of all lead intake routes and was demonstrated as a less significant exposure pathway to children’s blood, compared with ingestion. Whilst dermal exposure was negligible, diet and ingestion of soil and dust were the dominant parameters in terms of children’s blood lead prediction. The exposure assessment identified the changing role of dietary intake when house lead loadings varied. Recommendations were also made to conduct comprehensive site-specific human health risk assessment in future studies of lead exposure under a semi-arid climate. [ABSTRACT FROM AUTHOR]

The concentration of lead in indoor dust is a key parameter in the Integrated Exposure Uptake Biokinetic (IEUBK) model used by the U.S. Environmental Protection Agency (USEPA) to evaluate risks to children from lead in soil. The default assumption is that the concentration of lead in indoor dust is 70% of the concentration of lead in outdoor soil. This report reviews the basis of this assumption, and compares the assumption to data obtained at mining/smelting Superfund sites in USEPA Region 8. Data for lead concentrations measured in both indoor dust and outdoor soil at a number of different properties at nine different Superfund sites were fit to a linear model (Cdust = K0 + Ksd·Csoil). Based on ordinary linear regression, values of Ksd ranged from 0.04 to 0.34. Values of Ksd estimated using a simple method to account for measurement errors yielded values from 0.04 to 0.35. These findings indicate that the concentration of lead in dust at mining/smelting sites in Region 8 is usually not as large as the IEUBK default assumption indicates. Use of the default is likely to be protective, but will likely result in an overestimation of childhood exposure and risk from lead in soil. [ABSTRACT FROM AUTHOR]

The predictions of two source-to-dose models are evaluated with observed data collected in a village polluted by an operating secondary lead smelter. Both models were built up from several sub-models linked together and run using Monte-Carlo simulation. The first model system provides the distribution of the media-specific lead concentrations (air, soil, fruit, vegetables, and blood) in the whole area investigated. The second model provides an estimate of the concentration of exposure of specific individuals living in the study area. The predictions of the first model system were improved by performing a sensitivity analysis and using field data to correct the default value provided for the leaf wet density. However, in this case study, the model system tends to overestimate the exposure due to exposed vegetables. The second model was tested for nine children with contrasting exposure conditions. It managed to capture the blood levels for eight of them. In the last case, the exposure of the child by pathways not considered in the model may explain the failure of the model. The interest of this integrated model is to provide outputs with lower variance than the first model system, but further tests are necessary to conclude about its accuracy. [ABSTRACT FROM AUTHOR]

The Integrated Exposure Uptake Biokinetic (IEUBK) model is frequently used to estimate blood lead concentrations of children exposed to lead. Simulations with the IEUBK model were run to estimate the blood lead concentration in children living in the vicinity of a non-ferrous plant, situated in Hoboken, Belgium. Concentrations in soil ranged from 59–2425 mg Pb/kg dm, average concentrations in house dust ranged from 234–73394 mg Pb/kg dm. Measured blood lead concentrations in children aged 2–7 years were between 3 and 35 μ g/dl. Exposure sources were indoor dust in the house and the school, outdoor dust and soil in the home surrounding and at the school's playground, and suspended dust in the air. Soil ingestion values and lead exposure from food were changed to Flemish values. The model was able to predict the measured blood lead concentrations adequately except for the lowest exposure group. Predictions showed a systematic overestimation. Analysis of the data revealed that the neighbourhood's school is an important source of exposure to lead; indoor house dust dominates exposure for children going to school outside the area, because of the high concentrations of lead in indoor dust (3 to 5 times higher than in outdoor soil). [ABSTRACT FROM AUTHOR]

Lead pollution is an environmental priority. The evaluation of contaminated soils was often based on the results of the toxicity characteristic leaching procedure (TCLP) or the synthetic precipitation leaching procedure (SPLP). This paper presents a simple and fast screening test to detect soil contaminated by lead. The test is based on the chemistry of the stomach (Cl[sup -] concentration, pH 2, T = 37 °C) and simulates the incidental oral ingestion of soil by young children. The gastric juice simulation test (GJST) and the TCLP were applied to six size fractions from five soils. The GJST solubilized more Pb (up to 169 mg/l) than the TCLP especially for the smallest size fraction. Particle size had less effect on the TCLP. The percentage of lead released with the GJST, was most significant for the <63 µm size fraction and varied from 18 to 74% of the total lead content. Lead leached during the TCLP as a function of the total lead content showed poor linear regression coefficient (R) values for soils < 250 µm. R values were significant for all size fractions with the GJST. The pH of approximately 5 in the TCLP limits the solubilization of lead in the small size fractions. The five soils exceeded the toxicity threshold of 10 µgPb/dl of blood for a significant fraction of children between 0 and 36 months using the EPA's IEUBK model (Integrated Exposure Uptake Biokinetic). But the TCLP did not detect lead contamination in two of these five soils. The GJST proved to be a better estimator of lead bioaccessibility in the gastrointestinal tract. [ABSTRACT FROM AUTHOR]