Research highlights: elucidation of biogeochemical factors influencing methylmercury production

Abstract

Coal combustion and other human activities release inorganic mercury into the atmosphere at levels far greater than emissions from natural sources, significantly perturbing the global mercury cycle. Subsequent biogeochemical transformation of inorganic mercury to highly toxic methylmercury allows this heavy metal pollutant to enter the food web, where it bioaccumulates and can have severe impacts on animal and human populations. This Highlight features recent articles that examine in detail the effects of nutrient availability on the methylation–demethylation activity of microorganisms living in sediment with mercury contamination. By investigating differences in levels of sulfate, iron, organic matter, and other environmental factors, this research provides insight into the conditions that may favor methylmercury formation and thereby better inform remediation efforts in the future.