The joint study by the U.S. Geological Survey and the U.S. Fish and Wildlife Service appears in the Oct. 15 issue of Environmental Science & Technology, published by the American Chemical Society, the world's largest scientific society. Considerably smaller than Chinook (king) salmon, the silver coho salmon were introduced to the Great Lakes from North Pacific waters in the 1960s to control the lake's population of alewife, a member of the herring family, that had become a public health nuisance.
The two-year study measured the concentrations of PCBs in the salmon and estimated the efficiency with which the fish retain PCBs as a result of their natural diet of smaller fish such as alewife, bloater and smelt. The study also measured the level of PCBs in the smaller prey fish. The findings are consistent with a smaller, less extensive study of Lake Michigan coho salmon from about 15 years ago.
Iron Sulfate Speeds PCB Biodegradation, Reduces Toxicity
Iron sulfate offers a new approach to removing the chlorine molecules found in PCBs (polychlorinated biphenyls). Chlorine is the primary component involved in the toxic effects of this industrial compound. Partial PCB dechlorination takes place routinely in nature, thanks to certain bacteria. Unfortunately, in many instances only about 10 percent of the chlorine is removed this way, and researchers worldwide are looking for ways of increasing the effectiveness of this biodegradation.
Writing in the Nov. 1 issue of Environmental Science & Technology,
Michigan State University scientists report the results of a study involving the
addition of iron sulfate to PCB contaminated sediments. The jou
Contact: Marv Coyner
American Chemical Society