Reducing disease and death from Artisanal and Small-Scale Mining (ASM) - the urgent need for responsible mining in the context of growing global demand for minerals and metals for climate change mitigation.

Artisanal and small-scale mining (ASM) takes place under extreme conditions with a lack of occupational health and safety. As the demand for metals is increasing due in part to their extensive use in 'green technologies' for climate change mitigation, the negative environmental and occupational consequences of mining practices are disproportionately felt in low- and middle-income countries. The Collegium Ramazzini statement on ASM presents updated information on its neglected health hazards that include multiple toxic hazards, most notably mercury, lead, cyanide, arsenic, cadmium, and cobalt, as well as physical hazards, most notably airborne dust and noise, and the high risk of infectious diseases. These hazards affect both miners and mining communities as working and living spaces are rarely separated. The impact on children and women is often severe, including hazardous exposures during the child-bearing age and pregnancies, and the risk of child labor. We suggest strategies for the mitigation of these hazards and classify those according to primordial, primary, secondary, and tertiary prevention. Further, we identify knowledge gaps and issue recommendations for international, national, and local governments, metal purchasers, and employers are given. With this statement, the Collegium Ramazzini calls for the extension of efforts to minimize all hazards that confront ASM miners and their families.

Climate Change, Conflict, and Resource Extraction: Analyses of Nigerian Artisanal Mining Communities and Ominous Global Trends.

Background: The 2010 lead poisoning outbreak that claimed the lives of more than 400 children in artisanal gold mining villages in Zamfara, Nigeria is the tragic result of high gold prices, a geologic anomaly, and processing of ores in residential areas. Today, these villages face a growing crisis related to conflict and climate change. While the situation in Zamfara is unparalleled in many ways, the interactions between climate change, conflict, and mining consistently overlap a global scale. The scope of this analysis extends beyond the Nigerian crisis. Objectives: Understanding the complexities of challenges faced in Zamfara provides insight into how these issues impact vulnerable communities globally, and which strategies should be considered to solve this wicked problem. Methods: Analysis of the relationships between climate change, conflict, and mining in Zamfara and globally via literature review and examination of current events in the Sahel region. Findings: Supporting healthy artisanal mining communities, as was prioritized in Zamfara, must be a focus of environmental, health, and mineral management policies. This includes the consideration of multiple environmental health challenges, the protection of vulnerable groups, government-supported formalization programs, and meaningful involvement of local leadership in developing, implementing, and sustaining intervention strategies to enshrine ASM as a poverty reduction, climate change adaptation strategy. Conclusions: Rapidly rising metal prices and demand will continue to fuel environmental health crises associated with mining. Given Africa's growing role in the global mineral economy and the massive number of subsistence communities who will continue to be impacted by climate change, strategies that support responsible artisanal mining are both a necessity for preventing future health crises and an opportunity for promoting regional stability and peace.

Food contamination as a pathway for lead exposure in children during the 2010-2013 lead poisoning epidemic in Zamfara, Nigeria.

In 2010, an estimated 400 to 500 children died of acute lead poisoning associated with artisanal gold mining in Zamfara, Nigeria. Processing of gold ores containing up to 10% lead within residential compounds put residents, especially children, at the highest risk. Principal routes of exposure were incidental ingestion and inhalation of contaminated soil and dusts. Several Nigerian and international health organizations collaborated to reduce lead exposures through environmental remediation and medical treatment. The contribution of contaminated food to total lead exposure was assessed during the environmental health response. Objectives of this investigation were to assess the influence of cultural/dietary habits on lead exposure pathways and estimate the contribution of contaminated food to children's blood lead levels (BLLs). A survey of village dietary practices and staple food lead content was conducted to determine dietary composition, caloric intakes, and lead intake. Potential blood lead increments were estimated using bio-kinetic modeling techniques. Most dietary lead exposure was associated with contamination of staple cereal grains and legumes during post-harvest processing and preparation in contaminated homes. Average post-harvest and processed cereal grain lead levels were 0.32mg/kg and 0.85mg/kg dry weight, respectively. Age-specific food lead intake ranged from 7 to 78µg/day. Lead ingestion and absorption were likely aggravated by the dusty environment, fasting between meals, and nutritional deficiencies. Contamination of staple cereal grains by highly bioavailable pulverized ores could account for as much as 11%-34% of children's BLLs during the epidemic, and were a continuing source after residential soil remediation until stored grain inventories were exhausted.

Legacy lead arsenate soil contamination at childcare centers in the Yakima Valley, Central Washington, USA.

BACKGROUND: From the early 1900s to the 1950s, Yakima Valley orchards were commonly treated with lead arsenate (LA) insecticides. Lead (Pb) and arsenic (As) soil contamination has been identified on former orchard lands throughout Central Washington and pose a threat to human health and the environment. OBJECTIVES: The levels of Pb and As in soil and interior dust at participating childcare centers in the Upper Yakima Valley (Yakima County), Washington were sampled to explore exposure potential for young children. METHODS: Childcare center soils were collected from two soil depths, homogenized, and analyzed in bulk by a field-portable X-ray fluorescence spectrometer (XRF). Interior dust wipes samples were collected from at least two locations in each facility. All soil samples >250 mg/kg Pb and/or >20 As mg/kg were sieved to 250 µm, tested by XRF a second time, and analyzed via acid digestion and inductively coupled plasma mass spectrometry (ICP-MS) analysis. RESULTS: Bulk and sieved XRF results, as well as ICP-MS to XRF results were strongly correlated. Maximum Pb and As XRF results indicated that 4 (21%) and 8 (42%) of the 19 childcare centers surveyed exceeded the regulatory standard for Pb and As, respectively. Historic land use was significantly associated with elevated Pb and As levels. Interior dust loadings were below United States Environmental Protection Agency (EPA) guidelines. CONCLUSIONS: Childcare centers are areas of intensive use for children and when coupled with potential residential exposure in their homes, the total daily exposure is a potential hazard to children.

Estimating Children's Soil/Dust Ingestion Rates through Retrospective Analyses of Blood Lead Biomonitoring from the Bunker Hill Superfund Site in Idaho.

BACKGROUND: Soil/dust ingestion rates are important variables in assessing children's health risks in contaminated environments. Current estimates are based largely on soil tracer methodology, which is limited by analytical uncertainty, small sample size, and short study duration. OBJECTIVES: The objective was to estimate site-specific soil/dust ingestion rates through reevaluation of the lead absorption dose-response relationship using new bioavailability data from the Bunker Hill Mining and Metallurgical Complex Superfund Site (BHSS) in Idaho, USA. METHODS: The U.S. Environmental Protection Agency (EPA) in vitro bioavailability methodology was applied to archived BHSS soil and dust samples. Using age-specific biokinetic slope factors, we related bioavailable lead from these sources to children's blood lead levels (BLLs) monitored during cleanup from 1988 through 2002. Quantitative regression analyses and exposure assessment guidance were used to develop candidate soil/dust source partition scenarios estimating lead intake, allowing estimation of age-specific soil/dust ingestion rates. These ingestion rate and bioavailability estimates were simultaneously applied to the U.S. EPA Integrated Exposure Uptake Biokinetic Model for Lead in Children to determine those combinations best approximating observed BLLs. RESULTS: Absolute soil and house dust bioavailability averaged 33% (SD ± 4%) and 28% (SD ± 6%), respectively. Estimated BHSS age-specific soil/dust ingestion rates are 86-94 mg/day for 6-month- to 2-year-old children and 51-67 mg/day for 2- to 9-year-old children. CONCLUSIONS: Soil/dust ingestion rate estimates for 1- to 9-year-old children at the BHSS are lower than those commonly used in human health risk assessment. A substantial component of children's exposure comes from sources beyond the immediate home environment. CITATION: von Lindern I, Spalinger S, Stifelman ML, Stanek LW, Bartrem C. 2016. Estimating children's soil/dust ingestion rates through retrospective analyses of blood lead biomonitoring from the Bunker Hill Superfund Site in Idaho. Environ Health Perspect 124:1462-1470; http://dx.doi.org/10.1289/ehp.1510144.

Environmental Remediation to Address Childhood Lead Poisoning Epidemic due to Artisanal Gold Mining in Zamfara, Nigeria.

BACKGROUND: From 2010 through 2013, integrated health and environmental responses addressed an unprecedented epidemic lead poisoning in Zamfara State, northern Nigeria. Artisanal gold mining caused widespread contamination resulting in the deaths of > 400 children. Socioeconomic, logistic, and security challenges required remediation and medical protocols within the context of local resources, labor practices, and cultural traditions. OBJECTIVES: Our aim was to implement emergency environmental remediation to abate exposures to 17,000 lead poisoned villagers, to facilitate chelation treatment of children ≤ 5 years old, and to establish local technical capacity and lead health advocacy programs to prevent future disasters. METHODS: U.S. hazardous waste removal protocols were modified to accommodate local agricultural practices. Remediation was conducted over 4 years in three phases, progressing from an emergency response by international personnel to comprehensive cleanup funded and accomplished by the Nigerian government. RESULTS: More than 27,000 m3 of contaminated soils and mining waste were removed from 820 residences and ore processing areas in eight villages, largely by hand labor, and disposed in constructed landfills. Excavated areas were capped with clean soils (≤ 25 mg/kg lead), decreasing soil lead concentrations by 89%, and 2,349 children received chelation treatment. Pre-chelation geometric mean blood lead levels for children ≤ 5 years old decreased from 149 µg/dL to 15 µg/dL over the 4-year remedial program. CONCLUSIONS: The unprecedented outbreak and response demonstrate that, given sufficient political will and modest investment, the world's most challenging environmental health crises can be addressed by adapting proven response protocols to the capabilities of host countries. CITATION: Tirima S, Bartrem C, von Lindern I, von Braun M, Lind D, Anka SM, Abdullahi A. 2016. Environmental remediation to address childhood lead poisoning epidemic due to artisanal gold mining in Zamfara, Nigeria. Environ Health Perspect 124:1471-1478; http://dx.doi.org/10.1289/ehp.1510145.

Unknown risk: co-exposure to lead and other heavy metals among children living in small-scale mining communities in Zamfara State, Nigeria.

The lead poisoning crisis in Zamfara State, Northern Nigeria has been called the worst such case in modern history and it presents unique challenges for risk assessment and management of co-exposure to multiple heavy metals. More than 400 children have died in Zamfara as a result of ongoing lead intoxication since early in 2010. A review of the common toxic endpoints of the major heavy metals advances analysis of co-exposures and their common pathologies. Environmental contamination in Bagega village, examined by X-ray fluorescence of soils, includes lead, mercury, cadmium, arsenic and manganese. Co-exposure risk is explored by scoring common toxic endpoints and hazard indices to calculate a common pathology hazard risk ranking of Pb > As > Hg >> Cd > Mn. Zamfara presents an extreme picture of both lead and multiple heavy metal mortality and morbidity, but similar situations have become increasingly prevalent worldwide.

Linking geological and health sciences to assess childhood lead poisoning from artisanal gold mining in Nigeria.

BACKGROUND: In 2010, Médecins Sans Frontières discovered a lead poisoning outbreak linked to artisanal gold processing in northwestern Nigeria. The outbreak has killed approximately 400 young children and affected thousands more. OBJECTIVES: Our aim was to undertake an interdisciplinary geological- and health-science assessment to clarify lead sources and exposure pathways, identify additional toxicants of concern and populations at risk, and examine potential for similar lead poisoning globally. METHODS: We applied diverse analytical methods to ore samples, soil and sweep samples from villages and family compounds, and plant foodstuff samples. RESULTS: Natural weathering of lead-rich gold ores before mining formed abundant, highly gastric-bioaccessible lead carbonates. The same fingerprint of lead minerals found in all sample types confirms that ore processing caused extreme contamination, with up to 185,000 ppm lead in soils/sweep samples and up to 145 ppm lead in plant foodstuffs. Incidental ingestion of soils via hand-to-mouth transmission and of dusts cleared from the respiratory tract is the dominant exposure pathway. Consumption of water and foodstuffs contaminated by the processing is likely lesser, but these are still significant exposure pathways. Although young children suffered the most immediate and severe consequences, results indicate that older children, adult workers, pregnant women, and breastfed infants are also at risk for lead poisoning. Mercury, arsenic, manganese, antimony, and crystalline silica exposures pose additional health threats. CONCLUSIONS: Results inform ongoing efforts in Nigeria to assess lead contamination and poisoning, treat victims, mitigate exposures, and remediate contamination. Ore deposit geology, pre-mining weathering, and burgeoning artisanal mining may combine to cause similar lead poisoning disasters elsewhere globally.

Androgen dependent seasonal changes in muscle fiber type in the dewlap neuromuscular system of green anoles.

Green anoles (Anolis carolinensis) possess two sexually dimorphic neuromuscular systems involved in reproductive behaviors. One controls extension of a red throat fan (dewlap), which males employ during courtship, and the other controls intromission of copulatory organs (hemipenes). Although seasonal changes in circulating androgens mediate both courtship and copulatory behaviors, testosterone has differential effects on the underlying neuromuscular morphology. The present experiments were designed to test whether changes in muscle fiber type correspond to seasonal and androgenic regulation of reproductive behaviors in gonadally intact males (Experiment 1) or castrated males treated with either testosterone propionate or vehicle (Experiment 2). Gonadally intact males housed in breeding environmental conditions had a higher percentage of fast oxidative glycolytic fibers in the dewlap muscle than non-breeding males, but no effect of season on copulatory fibers was detected. Interestingly, testosterone treatment increased the percentage of fast oxidative glycolytic dewlap fibers independent of season, suggesting that routine changes in this hormone may mediate fiber type in gonadally intact males. In contrast, testosterone manipulation had little to no effect on copulatory muscle fiber type, demonstrating that a change in this feature is not the primary mediator for seasonal changes in male copulatory behaviors.