Dangerous Levels of Methylmercury Found in Every Fish Examined from 291 U.S. Freshwater Streams-


According to recent U.S. scientific research covering 291 freshwater streams throughout the country, analysts discovered mercury contamination in every fish out of hundreds, with more than a quarter of these fish containing concentrations of mercury levels exceeding standards set by the Environmental Protection Agency (EPA) for the protection of individuals who eat average quantities of fish. Additionally, more than two-thirds exceeded the EPA-set level of concern for fish eating mammals. “This study shows just how widespread mercury pollution has become in our air, watersheds, and many of our fish in freshwater streams,” Interior Secretary Ken Salazar said in a statement. The toxic substance enters the atmosphere due to air pollution caused by industrial emissions, and falls back into the surface through rainfall and coarse matter carried over long stretches. The primary source of atmospheric mercury has found to be coal-fired power plants, accordant with EPA research.

In the latest study, some of the highest levels of the contaminant were found in the coastal “blackwater” streams of North and South Carolina, Georgia, Florida and Louisiana; somewhat primitive regions surrounded by rich forests and wetlands. A hydrologist from the U.S. Geological Survey, Barbara Scudder, stresses that the characteristics of the area, by some means, develops the adaptation of mercury from its inorganic form in the environment to a more toxic, organic form – methylmercury – accounting for roughly 95 percent of the mercury found in fish. “Just as there are members of the human population, such as children and developing babies, that are sensitive to the mercury that they get, there are some ecosystems that are also more susceptible to producing methylmercury,” she said. She went on to mention that high concentrations were uncovered in some streams in the West fed by areas where mining was prevalent, also divulging that researchers generally sampled about five fish per studied stream, focusing on larger species like largemouth bass since they are more toward the top of the in-stream food chain. She proposes consuming the smaller pan variety more often, such as perch, crappie or bluegill to avoid any issues with contamination. The EPA has also said this year that it plans to develop new regulations under the Clean Air Act to manage air emissions of mercury from coal-fired plants.