Mercury Exposure Among Artisanal Gold Miners in Madre de Dios, Peru: A Cross-sectional Study

Abstract

Introduction Exposure to mercury, a toxic metal, occurs primarily from inhaling mercury vapors or consuming methylmercury-contaminated fish. One third of all anthropogenic mercury emissions worldwide are from artisanal gold mining, which uses mercury to extract gold. Although recent reports suggest that the Madre de Dios region in Peru (with >30,000 artisanal miners) has extensive mercury contamination, residents had never been assessed for mercury exposure. Thus, our objective was to quantify mercury exposure among residents of an artisanal mining town in Madre de Dios and to assess risk factors for exposure. Methods We conducted a cross-sectional assessment of 103 residents of an artisanal gold mining town in July 2010. Each participant provided a urine and blood sample and completed a questionnaire assessing potential exposures and health outcomes. We calculated geometric mean (GM) urine total mercury and blood methylmercury concentrations and compared log-transformed concentrations between subgroups using linear regression.Results One third (34.0 %) of participants were gold miners. All participants had detectable urine total mercury (GM, 5.5 μg/g creatinine; range, 0.7-151 μg/g creatinine) and 91 % had detectable blood methylmercury (GM, 2.7 μg/L; range, 0.6-10 μg/L); 13 participants (13 %) reported having kidney dysfunction or a neurological disorder. Urine total mercury concentrations were higher among people who heated gold-mercury amalgams compared with people who never heated amalgams (p<0.05); methylmercury concentrations were higher among fish consumers compared with nonfish consumers (p<0.05). Conclusion Our findings suggest that mercury exposure may be widespread in Huaypetue.

Mercury Levels in Human Hair and Farmed Fish near Artisanal and Small-Scale Gold Mining Communities in the Madre de Dios River Basin, Peru

“…A study of 103 ASGM miners in Madre de Dios in 2010 found that all participants had detectable levels of mercury in urine, and 91% had detectable levels of blood methylmercury [45]. As with the study by Ashe (2012) [44], Yard et al (2012) [45] found that higher fish consumption was associated with increased hair mercury levels; Yard et al further found that exposure to heated gold-mercury amalgam was correlated with higher mercury levels.…”

“…A 2012 study on the mercury levels in human hair among 104 participants in the town of Puerto Maldonado in Madre de Dios and 100 participants in an ASGM mining zone in the region, found that residence location and sex were correlated with higher mercury levels, and that the total levels of mercury in hair were significantly higher in the mining zones [44]. A study of 103 ASGM miners in Madre de Dios in 2010 found that all participants had detectable levels of mercury in urine, and 91% had detectable levels of blood methylmercury [45]. As with the study by Ashe (2012) [44], Yard et al (2012) [45] found that higher fish consumption was associated with increased hair mercury levels; Yard et al further found that exposure to heated gold-mercury amalgam was correlated with higher mercury levels.…”

“…One unpublished study demonstrated that the average hair mercury levels exceeded the US EPA Reference Concentration for human hair of 1 µg/g [43], and a second study showed that hair mercury levels were higher in ASGM areas than in non-mining areas [44]. High levels of mercury have also been found in the blood and urine of ASGM miners in Madre de Dios [45]. Additionally, hair mercury levels have been associated with a higher fish consumption [44,45].…”

“…High levels of mercury have also been found in the blood and urine of ASGM miners in Madre de Dios [45]. Additionally, hair mercury levels have been associated with a higher fish consumption [44,45]. The US EPA set a methylmercury Tissue Residue Criterion for fish tissue intended for human consumption at 0.3 µg MeHg/g fish tissue (wet weight) [46].…”

Neurological Status Disturbances Caused by Mercury Exposures from Artisanal Gold Mining Area in West Aceh, Aceh Province

“…Several research related to the impact of the use of mercury in artisanal gold mining had been done around the world ( [5], [6], [7], [8], [9]). In Indonesia, research on artisanal gold mining had been conducted ( [10], [11], [12], [13], [14]) but it is still limited on research topic related to the impact of mercury on neurological disturbances.…”