Impact of El Niño on Environmental Mercury and Human Exposure

NIEHS Grant: R21ES026960

William Pan, Ph.D.

Researchers at Duke University are working in the Peruvian Amazon to better understand how the combination of El Niño climate events and the growth of artisanal small-scale gold mining in the region may increase human exposure to the neurotoxic compound methylmercury (MeHg). Mining practices release mercury into nearby soil and rivers where it is transformed into methylmercury by bacteria and accumulates in fish and other aquatic life. Flooding events caused by El Niño may disrupt agricultural production, causing people to rely more on fish to meet their nutritional needs. To determine how these and other factors may increase human MeHg exposure, the research team is collecting and testing fish, sediment, and human biological samples for mercury and other metals during and after an El Niño. The researchers are establishing a birth cohort to examine if fish consumption during pregnancy results in high MeHg exposure for infants conceived or born during an El Niño event. They are also determining whether the amount of fish people eat changes due to an El Niño event. Study results will help clarify how El Niño flooding may increase exposure to the neurotoxic compound MeHg among people living in the Amazon. This research is especially important as El Niño events are projected to increase in the future.