Toxic Mercury Found In 300 Streams In The USA

A federal study of mercury contamination released Wednesday found the toxic substance in every fish tested at nearly 300 streams across the country, a finding that shows how widespread mercury pollution has become. U.S. Geological Survey scientists say they have detected mercury contamination in every fish sampled in 291 streams across the United States. The USGS said about a quarter of the fish were found to contain mercury at levels exceeding the U.S. Environmental Protection Agency's criterion for the protection of people who consume average amounts of fish. More than two-thirds of the fish exceeded the EPA level of concern for fish-eating mammals, the scientists said. According to researchers the main source of mercury to most of the streams tested, is emissions from coal-fired power plants. The mercury released from smokestacks rains down into waterways, where natural processes convert it into methyl-mercury, a form that allows the toxin to wind its way up the food chain into fish. The USGS study found some of the highest levels of mercury in fish in the "black-water" streams in North and South Carolina, Georgia, Florida and Louisiana. High levels of mercury in fish also were found in relatively undeveloped watersheds in the Northeast and the Upper Midwest. Elevated levels were noted in areas of the Western United States affected by mining. Mercury, a neurotoxin, is one of the most serious contaminants threatening our nation’s waters. Mercury has been known to damage the nervous system and cause learning disabilities in developing fetuses and young children. Alaska and Wyoming are the only states that haven't issued fish-consumption advisories because of mercury contamination. Some of the streams studied already had warnings. The Obama administration said it would begin crafting new regulations to control mercury emissions from power plants after a federal appeals court threw out plans drafted by the Bush administration. The Bush plan would have allowed power plants to buy and sell pollution credits, instead of requiring each plant to install equipment to reduce mercury pollution.