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NSF Grant Explores Methylmercury 8/31/2020


Researchers at the SUNY College of Environmental Science and Forestry (ESF) and Syracuse University (SU) will use a $500,000 grant from the National Science Foundation to deepen our knowledge of the dangers of methylmercury, a toxic substance believed to be one of the most poisonous among the mercury compounds.

Co-Principal investigators Dr. Hyatt Green from ESF and Dr. Svetoslava Todorova from SU will leverage the characteristics of local meromictic lakes - Green Lake (Fayetteville, New York) and Glacier Lake (Jamesville, New York) - to conduct their research.

"The water in most lakes turns over seasonally," said Green. "The water in these lakes doesn't cycle, so we have specific and stable microbial communities from top to bottom."

Meromictic lakes can usually be divided into three layers that don't mix. The lack of mixing between layers creates radically different environments for organisms to live in: among the consequences of this stratification, or stable layering, of lake waters is that the bottom layer receives little oxygen from the atmosphere, which means very few organisms can live in the environment.

"Some bacteria, however, are the exception," said Green. "Some bacteria in the depths of these lakes find oxygen poisonous and may be factors in the conversion from mercury to methylmercury."

Methylmercury is typically found in wet environments: bogs, swamps, marshes, and the Everglades, for example. According to the World Health Organization (WHO), mercury may have toxic effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin, and eyes. It is considered by the WHO to be among the top chemicals causing major public health concern.

Researchers will use metagenomic sequencing and other microbial techniques to understand how mercury is transformed into methylmercury. This research extends initial findings that suggested microbial dark matter (MDM) may be involved in the conversion of mercury to methylmercury.

"People are mainly exposed to methylmercury when they eat fish and shellfish that contain the compound," said Green. "Our work will provide a better understanding of where this methylmercury comes from. Knowing more about the organisms that produce methylmercury could help limit the production of the compound in the first place and help prevent harvesting of fish or shellfish from areas where these bacteria thrive."