Probabilistic estimates of prenatal lead exposure at 195 toxic hotspots in low- and middle-income countries.

BACKGROUND: Prior estimates of pediatric lead-related disease burden in low- and middle-income countries (LMICs) used population estimates of maternal blood lead levels (BLLs). This approach may underestimate fetal BLLs by not considering potentially high prenatal lead exposure from toxic hotspots. OBJECTIVES: We developed a probabilistic approach to using the Adult Lead Methodology (ALM) to estimate fetal BLLs from prenatal exposure to lead-contaminated soil at hotspots in the Toxic Site Identification Program (TSIP). METHODS: We created distributions for each ALM parameter using published literature and extracted soil lead measurements from the TSIP database. Each iteration of the probabilistic ALM randomly selected values from the input distributions to generate a site-specific fetal BLL estimate. For each site, we ran 5000 model iterations, producing a site-specific fetal BLL distribution. RESULTS: 195 TSIP sites, in 33 LMICs, met our study inclusion criteria; an estimated 820,000 women of childbearing age are at risk for lead exposure at these sites. The predicted geometric means (GM) for site-specific fetal BLLs ranged from 3.3 µg/dL to 534 µg/dL, and 98% of sites had estimated GM fetal BLLs >5 µg/dL, the current reference level of the United States Centers for Disease Control and Prevention (CDC), while 11 sites had estimated GM fetal BLLs above the CDC chelation threshold of 45 µg/dL. DISCUSSION: The TSIP soil lead data and this probabilistic approach to the ALM show that pregnant women living near TSIP sites may have BLLs that put their fetus at risk for neurologic damage and other sequelae, underscoring the need for interventions to reduce lead exposure at toxic hotspots.

Lead intoxicated children in Kabwe, Zambia.

Kabwe is a lead contaminated mining town in Zambia. Kabwe has extensive lead contaminated soil and children in Kabwe ingest and inhale high quantities of this toxic dust. The aim of this paper is to analyze the health impact of this exposure for children. Health data from three existing studies were re-analyzed. Over 95% of children living in the most affected townships had high blood lead levels (BLLs) > 10µg/dL. Approximately 50% of those children had BLLs ≥ 45µg/dL. The existing data clearly establishes the presence of a severe environmental health crisis in Kabwe which warrants immediate attention.

Improving human health outcomes with a low-cost intervention to reduce exposures from lead acid battery recycling: Dong Mai, Vietnam.

This study details the first comprehensive evaluation of the efficacy of a soil lead mitigation project in Dong Mai village, Vietnam. The village's population had been subject to severe lead poisoning for at least a decade as a result of informal Used Lead Acid Battery (ULAB) recycling. Between July 2013 to February 2015, Pure Earth and the Centre for Environment and Community Development (Hanoi, Vietnam) implemented a multi-faceted environmental and human health intervention. The intervention consisted of a series of institutional and low-cost engineering controls including the capping of lead contaminated surface soils, cleaning of home interiors, an education campaign and the construction of a work-clothes changing and bathing facility. The mitigation project resulted in substantial declines in human and environmental lead levels. Remediated home yard and garden areas decreased from an average surface soil concentration of 3940mg/kg to <100mg/kg. One year after the intervention, blood lead levels in children (<6 years old) were reduced by an average of 67%-from a median of 40.4µg/dL to 13.3µg/dL. The Dong Mai project resulted in significantly decreased environmental and biological lead levels demonstrating that low-cost, rapid and well-coordinated interventions could be readily applied elsewhere to significantly reduce preventable human health harm.

Burden of disease resulting from lead exposure at toxic waste sites in Argentina, Mexico and Uruguay.

BACKGROUND: Though lead contaminated waste sites have been widely researched in many high-income countries, their prevalence and associated health outcomes have not been well documented in low- and middle-income countries. METHODS: Using the well-established health metric disability-adjusted life year (DALY) and an exposure assessment method developed by Chatham-Stephens et al., we estimated the burden of disease resulting from exposure to lead at toxic waste sites in three Latin American countries in 2012: Argentina, Mexico and Uruguay. Toxic waste sites identified through Pure Earth's Toxic Sites Identification Program (TSIP) were screened for lead in both biological and environmental sample media. Estimates of cardiovascular disease incidence and other outcomes resulting from exposure to lead were utilized to estimate DALYs for each population at risk. RESULTS: Approximately 316,703 persons in three countries were at risk of exposure to pollutants at 129 unique sites identified through the TSIP database. Exposure to lead was estimated to result in between 51,432 and 115,042 DALYs, depending on the weighting factor used. The estimated burden of disease caused by exposure to lead in this analysis is comparable to that estimated for Parkinson's disease and bladder cancer in these countries. CONCLUSIONS: Lead continues to pose a significant public health risk in Argentina, Mexico, and Uruguay. The burden of disease in these three countries is comparable with other widely recognized public health challenges. Knowledge of the relatively high number of DALYs associated with lead exposure may be used to generate support and funding for the remediation of toxic waste sites in these countries and others.

The pediatric burden of disease from lead exposure at toxic waste sites in low and middle income countries.

BACKGROUND: The impact of lead from toxic waste sites on children in low and middle income countries has not been calculated due to a lack of exposure data. We sought to calculate this impact in Disability Adjusted Life Years (DALYs). MATERIALS AND METHODS: Using an Integrated Exposure Uptake Biokinetic (IEUBK) model, we converted soil and drinking water lead levels from sites in the Blacksmith Institute's Toxic Sites Identification Program (TSIP) into mean blood lead levels (BLLs). We then calculated the incidence of mild mental retardation (MMR) and DALYs resulting from these BLLs. RESULTS: The TSIP included 200 sites in 31 countries with soil (n=132) or drinking water (n=68) lead levels, representing 779,989 children younger than 4 years of age potentially exposed to lead. Environmental lead levels produced a range of BLLs from 1.56 to 104.71 µg/dL. These BLLs equated to an estimated loss of 5.41-8.23 IQ points, resulting in an incidence of MMR of 6.03 per 1000 population and 76.1 DALYs per 1000 population. DISCUSSION: Soil and water lead levels at toxic waste sites predict BLLs that lower the intelligence quotient (IQ), with the resulting MMR potentially limiting individual- and country-level development. The preventable burden of disease produced by these sites highlights the need for toxic waste sites to be systematically identified, evaluated, and remediated.

The burden of disease from pediatric lead exposure at hazardous waste sites in 7 Asian countries.

Identification and systematic assessment of hazardous wastes sites in low and middle-income countries has lagged. Hazardous waste problems are especially severe in lower income Asian countries where environmental regulations are non-existent, nonspecific or poorly enforced. In these countries extensive unregulated industrial development has created waste sites in densely populated urban areas. These sites appear to pose significant risks to public health, and especially to the health of children. To assess potential health risks from chemical contamination at hazardous waste sites in Asia, we assessed 679 sites. A total of 169 sites in 7 countries were classified as contaminated by lead. Eighty-two of these sites contained lead at levels high enough to produce elevated blood lead levels in surrounding populations. To estimate the burden of pediatric lead poisoning associated with exposure to lead in soil and water at these 82 lead-contaminated sites, we used standard toxicokinetic models that relate levels of lead in soil and water to blood lead levels in children. We calculated blood lead levels, and we quantified losses of intelligence (reductions in IQ scores) that were attributable to lead exposure at these sites. We found that 189,725 children in the 7 countries are at risk of diminished intelligence as a consequence of exposure to elevated levels of lead in water and soil at hazardous waste sites. Depending on choice of model, these decrements ranged from 4.94 to 14.96 IQ points. Given the restricted scope of this survey and the conservative estimation procedures employed, this number is almost certainly an underestimate of the full burden of disease. Exposure to toxic chemicals from hazardous waste sites is an important and heretofore insufficiently examined contributor to the Global Burden of Disease.

Approaches to systematic assessment of environmental exposures posed at hazardous waste sites in the developing world: the Toxic Sites Identification Program.

In the developing world, environmental chemical exposures due to hazardous waste sites are poorly documented. We describe the approach taken by the Blacksmith Institute's Toxic Sites Identification Program in documenting environmental chemical exposures due to hazardous waste sites globally, identifying sites of concern and quantifying pathways, populations, and severity of exposure. A network of local environmental investigators was identified and trained to conduct hazardous waste site investigations and assessments. To date, 2,095 contaminated sites have been identified within 47 countries having an estimated population at risk of 71,500,000. Trained researchers and investigators have visited 1,400 of those sites. Heavy metals are the leading primary exposures, with water supply and ambient air being the primary routes of exposure. Even though chemical production has occurred largely in the developed world to date, many hazardous waste sites in the developing world pose significant hazards to the health of large portions of the population. Further research is needed to quantify potential health and economic consequences and identify cost-effective approaches to remediation.

Bovine lead exposure from informal battery recycling in India.

We provide an estimate of annual bovine lead exposure and attributable mortality at informal lead acid battery recycling sites in India. We use Pure Earth's Toxic Sites Identification Program database, the FAO's Gridded Livestock dataset, and a Poisson plume model of lead particle air dispersion to estimate site-level mortality. We calculate that India suffers 2370 excess bovine fatalities each year, resulting in more than USD $2.1 million of economic damage. The distribution of damages by location is highly skewed. While we find most sites (86.3%) induce no mortalities, 6.2% of sites induce minor damage (1 to 5 fatalities), 4.1% induce moderate damage (6 to 20 fatalities), and 3.4% induce severe damage (21 + fatalities). These findings highlight the importance of geospatial data to prioritize mitigation efforts and identify a previously unquantified burden on the rural poor.

Blood lead levels in low-income and middle-income countries: a systematic review.

BACKGROUND: Since the global phase-out of leaded petrol, reports have suggested that lead exposure remains substantial or is increasing in some low-income and middle-income countries (LMICs). However, few studies have attempted to systematically assess blood lead levels over the full range of LMICs. We aimed to describe values for blood lead level in LMICs. METHODS: In this systematic review, we searched PubMed for studies published between Jan 1, 2010, and Oct 31, 2019, that reported blood lead levels in the 137 countries in World Bank LMIC groupings. Studies were reviewed for inclusion if they contained blood lead level data from human populations residing in any given country; comprised at least 30 participants; presented blood lead level data derived from venous, capillary, or umbilical cord samples of whole blood; had data that were collected after Dec 31, 2004; and were published in English. Data on blood lead level were extracted and pooled, as appropriate, to make country-specific estimates of the distribution of background blood lead levels among children and adults, along with information on specific sources of exposure where available. This study is registered with PROSPERO, number CRD42018108706. FINDINGS: Our search yielded 12 695 studies, of which 520 were eligible for inclusion (1100 sampled populations from 49 countries comprising 1 003 455 individuals). Pooled mean blood lead concentrations in children ranged from 1·66 µg/dL (SD 3·31) in Ethiopia to 9·30 µg/dL (11·73) in Palestine, and in adults from 0·39 µg/dL (1·25) in Sudan to 11·36 µg/dL (5·20) in Pakistan. Background values for blood lead level in children could be pooled in 34 countries and were used to estimate background distributions for 1·30 billion of them. 632 million children (95% CI 394 million-780 million; 48·5%) were estimated to have a blood lead level exceeding the US Centers for Disease Control's reference value of 5 µg/dL. Major sources of lead exposure were informal lead acid battery recycling and manufacture, metal mining and processing, electronic waste, and the use of lead as a food adulterant, primarily in spices. INTERPRETATION: Many children have a blood lead level exceeding 5 µg/dL in LMICs, despite leaded petrol phase-outs. Given the toxicity of lead, even at low amounts of exposure, urgent attention is required to control exposures and to expand population-based sampling in countries with no or scant data. FUNDING: This work was supported by the United States Agency for International Development (Cooperative Agreement number AID-OAA-A-16-00019).

Elevated Levels of Lead (Pb) Identified in Georgian Spices.

Background: Human lead (Pb) exposure can result in a number of adverse health outcomes, particularly in children. Objective: An assessment of lead exposure sources was carried out in the Republic of Georgia following a nationally representative survey that found elevated blood lead levels (BLLs) in children. Methods: A range of environmental media were assessed in 25 homes and four bazaars spanning five regions. In total, 682 portable X-Ray Fluorescence measurements were taken, including those from cookware (n = 53); paint (n = 207); soil (n = 91); spices (n = 128); toys (n = 78); and other media (n = 125). In addition, 61 dust wipes and 15 water samples were collected and analyzed. Findings: Exceptionally high lead concentrations were identified in multiple spices. Median lead concentrations in six elevated spices ranged from 4-2,418 times acceptable levels. Median lead concentrations of all other media were within internationally accepted guidelines. The issue appeared to be regional in nature, with western Georgia being the most highly affected. Homes located in Adjara and Guria were 14 times more likely to have lead-adulterated spices than homes in other regions. Conclusions: Further study is required to determine the source of lead contamination in spices. Policy changes are recommended to mitigate potential health impacts. The results of this study contribute to a growing body of evidence that points to adulterated spices as a significant source of human lead exposure.

Assessment of the Presence of Soil Lead Contamination Near a Former Lead Smelter in Mombasa, Kenya.

BACKGROUND: The informal settlement of Owino Uhuru near an abandoned lead smelter attracted international attention due to an apparent lead poisoning event. Despite this attention, the environmental data collected to date do not indicate high levels of residual contamination. OBJECTIVES: To further confirm previous findings and determine any necessary risk mitigation measures, an assessment of surface soil lead concentrations was conducted in the community. METHODS: Investigators carried out an assessment of the soil in a ~12,000 m2 section of the Owino Uhuru neighborhood over the course of a single day in June 2017 with the assistance of community leaders. Fifty-nine in situ soil measurements were taken using an Innov-X tube-based (40 kV) alpha X-ray fluorescence instrument (pXRF). RESULTS: The assessment found that mean surface soil lead concentrations in areas conducive to exposure were 110 mg/kg (95% CI: 54-168); below United States Environmental Protection Agency and the Environment Canada screening levels of 400 mg/kg and 140 mg/kg, respectively. CONCLUSIONS: There is likely no current need for risk mitigation activities in the community. These results could inform discussions on the allocation of public health spending. COMPETING INTERESTS: The authors declare no competing financial interests. BE, VOO, CN and JSF are employees of Pure Earth. MPT sits on the Editorial Board of the Journal of Health and Pollution.

Assessment of the prevalence of lead-based paint exposure risk in Jakarta, Indonesia.

While lead-based paint has been banned for use in residential settings in most high-income countries, it remains commonly available in many low- and middle-income countries (LMICs). Despite its continued availability, little is known about the specific exposure risk posed by lead-based paint in LMICs. To address this knowledge gap, an assessment of home and preschool dust and paint was carried out in Greater Jakarta, Indonesia. A team of investigators used field portable X-ray Fluorescence (pXRF) to measure 1574 painted surfaces for the presence of lead (mg/cm2) and collected 222 surface dust wipe samples for lead loading (µg/m2) from 103 homes and 19 preschools across 13 different neighborhoods of Jakarta. The assessment found that 2.7% (n = 42) of pXRF measurements and 0.05% (n = 1) of dust wipe samples exceeded the commonly applied USEPA guideline values for paint (1 mg/cm2) and dust (floors: 431 µg/m2; window sills: 2691 µg/m2). Thus, contrary to expectations the locations analyzed in Greater Jakarta showed that exposure risk to lead-based paint appears low. Further study is required in other settings to confirm the findings here. Precautionary measures, such as the proposed ban on lead-based paint, should be taken to prevent the significant social and economic costs associated with lead exposure.

Cost Effectiveness of Environmental Lead Risk Mitigation in Low- and Middle-Income Countries.

Environmental remediation efforts in low- and middle-income countries have yet to be evaluated for their cost effectiveness. To address this gap we calculate a cost per Disability Adjusted Life Year (DALY) averted following the environmental remediation of the former lead smelter and adjoining residential areas in Paraiso de Dios, Haina, the Dominican Republic, executed from 2009 to 2010. The remediation had the effect of lowering surface soil lead concentrations to below 100 mg/kg and measured geometric mean blood lead levels (BLLs) from 20.6 µg/dL to 5.34 ug/dL. Because BLLs for the entire impacted population were not available, we use environmental data to calculate the resulting disease burden. We find that before the intervention 176 people were exposed to elevated environmental lead levels at Paraiso de Dios resulting in mean BLLs of 24.97 (95% CI: 24.45-25.5) in children (0-7 years old) and 13.98 µg/dL (95% CI: 13.03-15) in adults. We calculate that without the intervention these exposures would have resulted in 133 to 1,096 DALYs and that all of these were averted at a cost of USD 392 to 3,238, depending on assumptions made. We use a societal perspective, meaning that we include all costs regardless of by whom they were incurred and estimate costs in 2009 USD. Lead remediation in low- and middle-income countries is cost effective according to World Health Organization thresholds. Further research is required to compare the approach detailed here with other public health interventions.

A meta-analysis of blood lead levels in India and the attributable burden of disease.

Multiple studies in India have found elevated blood lead levels (BLLs) in target populations. However the data have not yet been evaluated to understand population-wide exposure levels. We used arithmetic mean blood lead data published from 2010 to 2018 on Indian populations to calculate the average BLLs for multiple subgroups. We then calculated the attributable disease burden in IQ decrement and Disability Adjusted Life Years (DALYs). Our Pubmed search yielded 1066 articles. Of these, 31 studies representing the BLLs of 5472 people in 9 states met our study criteria. Evaluating these, we found a mean BLL of 6.86 µg/dL (95% CI: 4.38-9.35) in children and 7.52 µg/dL (95% CI: 5.28-9.76) in non-occupationally exposed adults. We calculated that these exposures resulted in 4.9 million DALYs (95% CI: 3.9-5.6) in the states we evaluated. Population-wide BLLs in India remain elevated despite regulatory action to eliminate leaded petrol, the most significant historical source. The estimated attributable disease burden is larger than previously calculated, particularly with regard to associated intellectual disability outcomes in children. Larger population-wide BLL studies are required to inform future calculations. Policy responses need to be developed to mitigate the worst exposures.

Prevention-intervention strategies to reduce exposure to e-waste.

As one of the largest waste streams, electronic waste (e-waste) production continues to grow in response to global demand for consumer electronics. This waste is often shipped to developing countries where it is disassembled and recycled. In many cases, e-waste recycling activities are conducted in informal settings with very few controls or protections in place for workers. These activities involve exposure to hazardous substances such as cadmium, lead, and brominated flame retardants and are frequently performed by women and children. Although recycling practices and exposures vary by scale and geographic region, we present case studies of e-waste recycling scenarios and intervention approaches to reduce or prevent exposures to the hazardous substances in e-waste that may be broadly applicable to diverse situations. Drawing on parallels identified in these cases, we discuss the future prevention and intervention strategies that recognize the difficult economic realities of informal e-waste recycling.

[Intelligence quotient loss in Mexican pottery artisan's children]. / Pérdida de coeficiente intelectual en hijos de alfareros mexicanos.

BACKGROUND: In Mexico, artisans frequently use lead oxide or greta in order to produce utensils, which are destined to preparation and storage of food and drinks. Additionally, the risk of lead poisoning of artisans and their families is greater than in general population, and within these families, children are the most susceptible to lead poisoning. The aim of this study was to estimate IQ loss in Mexican children from potter families exposed to lead. METHODS: Lead concentrations in soil were determined in 19 potter's homes that functioned as pottery workshops in seven Mexican states between 2009 and 2012. This information was used to estimate blood lead levels through the integrated exposure uptake biokinetic (IEUBK) model. The loss of IQ points was then estimated according to the Lanphear and Schwartz models. RESULTS: The mean lead concentration found in the workshops' soil was 1098.4 ppm. Blood lead levels estimated in children under 8 years old were 26.4 µg/dL and the loss of IQ points comprised from 7.13 to 8.84 points depending on the model. CONCLUSIONS: It is possible that 11 children from families of artisans in Mexico may be losing between 7.13 to 8.84 IQ points, due to lead exposure in their houses-workshops. This loss in IQ points could have important health, economic and social impacts.

Introducción: en México, los alfareros continúan usando frecuentemente el óxido de plomo o greta para producir utensilios, los cuales se destinan a la preparación y almacenamiento de alimentos y bebidas. Adicionalmente, el riesgo de intoxicación por plomo de los alfareros y sus familias es mayor que en la población general, y en tales familias, los niños son los más susceptibles a la intoxicación por plomo. El objetivo del estudio fue estimar la pérdida de puntos de coeficiente intelectual (CI) en hijos de alfareros mexicanos expuestos al plomo. Métodos: durante el periodo de 2009 a 2012 se determinaron las concentraciones de plomo en suelo de 19 casas-talleres de alfareros en siete estados mexicanos. Esta información se utilizó para estimar el nivel de plomo en sangre, por medio del modelo biocinético integrado de absorción por exposición (IEUBK, por sus siglas en inglés). Posteriormente, se calcularon los puntos perdidos de CI según los modelos de Schwartz y Lanphear. Resultados: la concentración promedio de plomo en suelo fue de 1098.4 ppm. Se estimó un nivel de plomo en sangre de 26.4 µg/dL para menores de 8 años. La pérdida de puntos de CI estimada fue 7.13 y 8.84, según el modelo utilizado. Conclusión: es posible que al menos 11 niños de familias alfareras mexicanas estén perdiendo entre 7.13 y 8.84 puntos de CI, debido a la exposición al plomo en sus casas-talleres, lo que supone importantes impactos económicos, sociales y de salud.

Global Burden of Disease of Mercury Used in Artisanal Small-Scale Gold Mining.

BACKGROUND: Artisanal small-scale gold mining (ASGM) is the world's largest anthropogenic source of mercury emission. Gold miners are highly exposed to metallic mercury and suffer occupational mercury intoxication. The global disease burden as a result of this exposure is largely unknown because the informal character of ASGM restricts the availability of reliable data. OBJECTIVE: To estimate the prevalence of occupational mercury intoxication and the disability-adjusted life years (DALYs) attributable to chronic metallic mercury vapor intoxication (CMMVI) among ASGM gold miners globally and in selected countries. METHODS: Estimates of the number of artisanal small-scale gold (ASG) miners were extracted from reviews supplemented by a literature search. Prevalence of moderate CMMVI among miners was determined by compiling a dataset of available studies that assessed frequency of intoxication in gold miners using a standardized diagnostic tool and biomonitoring data on mercury in urine. Severe cases of CMMVI were not included because it was assumed that these persons can no longer be employed as miners. Cases in workers' families and communities were not considered. Years lived with disability as a result of CMMVI among ASG miners were quantified by multiplying the number of prevalent cases of CMMVI by the appropriate disability weight. No deaths are expected to result from CMMVI and therefore years of life lost were not calculated. Disease burden was calculated by multiplying the prevalence rate with the number of miners for each country and the disability weight. Sensitivity analyses were performed using different assumptions on the number of miners and the intoxication prevalence rate. FINDINGS: Globally, 14-19 million workers are employed as ASG miners. Based on human biomonitoring data, between 25% and 33% of these miners-3.3-6.5 million miners globally-suffer from moderate CMMVI. The resulting global burden of disease is estimated to range from 1.22 (uncertainty interval [UI] 0.87-1.61) to 2.39 (UI 1.69-3.14) million DALYs. CONCLUSIONS: This study presents the first global and country-based estimates of disease burden caused by mercury intoxication in ASGM. Data availability and quality limit the results, and the total disease burden is likely undercounted. Despite these limitations, the data clearly indicate that mercury intoxication in ASG miners is a major, largely neglected global health problem.

Disability Weights for Chronic Mercury Intoxication Resulting from Gold Mining Activities: Results from an Online Pairwise Comparisons Survey.

In artisanal small-scale gold mining, mercury is used for gold-extraction, putting miners and nearby residents at risk of chronic metallic mercury vapor intoxication (CMMVI). Burden of disease (BoD) analyses allow the estimation of the public health relevance of CMMVI, but until now there have been no specific CMMVI disability weights (DWs). The objective is to derive DWs for moderate and severe CMMVI. Disease-specific and generic health state descriptions of 18 diseases were used in a pairwise comparison survey. Mercury and BoD experts were invited to participate in an online survey. Data were analyzed using probit regression. Local regression was used to make the DWs comparable to the Global Burden of Disease (GBD) study. Alternative survey (visual analogue scale) and data analyses approaches (linear interpolation) were evaluated in scenario analyses. A total of 105 participants completed the questionnaire. DWs for moderate and severe CMMVI were 0.368 (0.261-0.484) and 0.588 (0.193-0.907), respectively. Scenario analyses resulted in higher mean values. The results are limited by the sample size, group of interviewees, questionnaire extent, and lack of generally accepted health state descriptions. DWs were derived to improve the data basis of mercury-related BoD estimates, providing useful information for policy-making. Integration of the results into the GBD DWs enhances comparability.

The Global Burden of Lead Toxicity Attributable to Informal Used Lead-Acid Battery Sites.

BACKGROUND: Prior calculations of the burden of disease from environmental lead exposure in low- and middle-income countries (LMICs) have not included estimates of the burden from lead-contaminated sites because of a lack of exposure data, resulting in an underestimation of a serious public health problem. OBJECTIVE: We used publicly available statistics and detailed site assessment data to model the number of informal used lead-acid battery (ULAB) recyclers and the resulting exposures in 90 LMICs. We estimated blood lead levels (BLLs) using the US Environment Protection Agency's Integrated Exposure Uptake Biokinetic Model for Lead in Children and Adult Lead Model. Finally, we used data and algorithms generated by the World Health Organization to calculate the number of attributable disability adjusted life years (DALYs). RESULTS: We estimated that there are 10,599 to 29,241 informal ULAB processing sites where human health is at risk in the 90 countries we reviewed. We further estimated that 6 to 16.8 million people are exposed at these sites and calculate a geometric mean BLL for exposed children (0-4 years of age) of 31.15 µg/dL and a geometric mean BLL for adults of 21.2 µg/dL. We calculated that these exposures resulted in 127,248 to 1,612,476 DALYs in 2013. CONCLUSIONS: Informal ULAB processing is currently causing widespread lead poisoning in LMICs. There is an urgent need to identify and mitigate exposures at existing sites and to develop appropriate policy responses to minimize the creation of new sites.