A close look at arsenic and mercury

The Dartmouth Toxic Metals Superfund Research Program currently focuses on arsenic and mercury, number one and three on the Agency for Toxic Substances and Disease Registry 2017 Substance Priority List of hazardous substances commonly found in Superfund sites in the U.S. All of our research projects are examining these two metals in detail.

In particular, we want to know:

• the natural and man-made sources of arsenic and mercury in the environment and their relative contributions to human exposure;
• how arsenic, mercury, and other metals move through ecosystems;
• how methylmercury is taken up in aquatic ecosystems and how it ends up in the fish that are most commonly consumed by humans;
• whether arsenic at levels found in drinking water in the U.S. raises the risk of human disease including lung disease, respiratory infections, and premature births;
• whether arsenic at levels found in food in the U.S. raises the same risks; and
• precisely how arsenic affects the cellular processes that are known to contribute to cardiovascular, lung and heart disease, and cancer.

Our research on arsenic also includes identifying molecular changes that act as warning flags indicating that cells have been exposed, affected or are particularly susceptible to damage by arsenic or other harmful metals. This research will contribute to a better understanding of the way arsenic affects living systems and will be useful in monitoring exposure in people and the environment. In addition, by examining the uptake, transport and storage of arsenic in plants like rice, researchers hope to learn how to make our food crops safer for human consumption.

Our research on mercury is identifying the types of aquatic ecosystems that contain fish that are high in methylmercury,  providing a scientific basis for establishing guidelines to reduce human exposures to mercury via fish consumption. To do so, scientists must first determine how methylmercury moves through aquatic ecosystems and further, pinpoint the factors that contribute to higher levels of methylmercury in aquatic food webs.