U.S. environmentalists have found reducing atmospheric mercury emissions can quickly reduce mercury levels in lake fish.

A three-year study by the Smithsonian Environmental Research Center showed an increase in mercury loading at rates relevant to atmospheric deposition resulted in a significant increase in methylmercury production and accumulation in fish in only three years.

"This is good news," said Cynthia Gilmour, a co-investigator of the study. "It means that a reduction in new mercury loads to many lakes should result in lower mercury in fish within a few years."

Researchers determined methylmercury -- the type that accumulates in fish -- was more readily produced from newly deposited mercury than from historical mercury contamination already buried in lake sediments. That, they said, means methylmercury in lakes should decline quickly if mercury deposition is reduced.

Additionally, the study team found that mercury added directly to the lake surface was rapidly accumulated into fish, while essentially none of the mercury deposited to the lake’s watershed was found in fish after the three-year period.

The study is detailed in the Proceedings of the National Academy of Science. // Copyright 2007 by United Press International





Publication date: 21 September 2007   

Source:

Archive