Environmental Health Consequences of Mercury Exposure for South American Communities

The use of mercury for the mining of gold and other precious metals represents the largest anthropogenic source of mercury to the atmosphere. Much of these emissions originate from artisanal or small scale mining practices in developing regions of the world, including South America, Africa and Asia. In this research, we are investigating mercury contamination in sediments and soils stemming from current and historical mining activities in South American mining communities  and the implications of this contamination for human health.

We are currently focused on the tropical Madre de Dios (MDD) region of Peru, a watershed in the Amazon Basin that is facing major emerging environmental and health threats due to rapid increases in artisanal gold mining, road development, and agricultural expansion.  The region is the among the most economically disadvantaged in Latin America, though in the last few years it has seen much immigration as people are lured by the economic promise of participating in gold mining and processing, an illegal but rapidly growing sector of the economy. Artisanal mining has a potentially devastating impact on human and environmental welfare due to the use of mercury in the amalgamation of gold.  Our has worked to delineate the extent of mercury contamination in the MDD watershed, and the impact on economic livelihood and overall health for indigenous and non-indigenous populations in the region. This work has included (1) Quantification of mercury accumulation in river sediment and fish; (2) Evaluations of the impact of human mercury exposure; and (3) Development of sediment transport models to identify where conservation efforts can be focused.

In past work in the region, we also investigated mercury contamination within urban communities of the Andean mining region in South America. During the Spanish colonial period (from 16th to 19th centuries), mining towns such as Huancavelica (Peru) and Potosí (Bolivia) were the sites of the largest precious metals mines in the world. Mercury was mined in Peru and used extensively across the Andean region to extract silver and other metals from ore deposits. Mercury use continues today in artisanal (small-scale) mining practices. In our research, we studied historical mercury contamination in urban communities as a result of mining from centuries ago, a legacy that still persists today. This work involved review of archival maps and records from the colonial period, modeling of historical atmospheric mercury levels in area, and quantification of soil mercury levels and exposure to present-day residents of these communities.  

This research is supported by the Duke Global Health Institute, the Duke Superfund Research Program, and the Duke Bass Connections Program.

Selected publications:

Weinhouse, C.; Gallis, J.A.; Ortiz, E.; Berky, A.J.; Morales, A.M.; Diringer, S.E.; Harrington, J.; Bullins, P.; Rogers, L.; Hare-Grogg, J.; Hsu-Kim, H.; Pan, W.K. (2020) A population-based mercury exposure assessment near an artisanal and small-scale gold mining site in the Peruvian Amazon. J. Exposure Science and Environmental Epidemiology. DOI: 10.1038/s41370-020-0234-2

Reuben, A;  Frischtak, H.; Berky, A.; Ortiz, E.J.; Morales A.M.; Hsu-Kim, H.; Pendergast, L.L.; Pan, W.K. (2020) Elevated Hair Mercury Levels Are Associated With Neurodevelopmental Deficits in Children Living Near Artisanal and Small‐Scale Gold Mining in Peru. GeoHealth. 4(5), e2019GH000222. DOI: 10.1029/2019GH000222.Diringer, S.E.; Berky, A.; Marani, M.; Ortiz, E.J.; Karatum, O.; Plata, D.L.; Pan, W.K.; Hsu-Kim, H. (2020) Deforestation Due to Artisinal and Small-Scale Gold Mining Exacerbates Soil and Mercury Mobilization in Madre de Dios, Peru. Environ. Sci. & Technol. DOI: 10.1021/acs.est.9b06620

Feingold, B.J.; Berky, A.; Hsu-Kim, H.; Rojas, E.; Pan, W.K. (2019) Population based dietary exposure to mercury through fish consumption in the Southern Peruvian Amazon. Environmental Research. 108720. DOI: 10.1016/j.envres.2019.108720

Wyatt, L.; Permar, S.R.; Ortiz, E.; Berky, A.; Woods, C.W.; Fouda Amouou, G.; Itell, H.; Hsu-Kim, H.; Pan, W.K. (2019). Mercury Exposure and Poor Nutritional Status Reduce Response to Six Expanded Program on Immunization Vaccines in Children: An Observational Cohort Study of Communities Affected by Gold Mining in the Peruvian Amazon. Intl. J. Environ. Res Public Health. 16(4), 638. DOI: 10.3390/ijerph16040638

Weinhouse, C.; Ortiz, E.J.; Berky, A.J.; Bullins, P.; Hare-Grogg, J.; Rogers, L.; Morales, A.-M.; Hsu-Kim, H.; Pan, W.K. (2017). Hair Mercury Level is Associated with Anemia and Micronutrient Status in Children Living Near Artisanal and Small-Scale Gold Mining in the Peruvian Amazon. American J of Tropical Medicine and Hygiene. 97(6), 1886-1897. DOI: https://doi.org/10.4269/ajtmh.17-0269

McEwen, A.R.; Hsu-Kim, H.; Robins, N.A.; Hagan, N.A.; Halabi, S.; Barras, O.; Richter, D.; Vandenberg, J.J. (2016). Residential metal contamination and potential health risks of exposure in adobe brick houses in Potosí, Bolivia. Sci. Total. Environ. 562, 237-246. DOI: 10.1016/j.scitotenv.2016.03.152.

Diringer, S.; Feingold, B; Ortiz, E.J.; Gallis, J.A.; Araújo-Flores, J.M.; Berky, A.; Pan, W.K.; Hsu-Kim, H. (2015). River transport of mercury from artisanal and small-scale gold mining and risks for dietary mercury exposure in Madre de Dios, Peru. Environ. Sci.: Processes & Impacts.17, 478-487.DOI: 10.1039/C4EM00567H.