PCB levels decline in Lake Michigan coho, chinook

摘要

Coho and chinook salmon in Lake Michigan are continuing to show decreased levels of banned industrial chemicals in their tissue, according to researchers. A study by Wisconsin's Department of Natural Resources found that polychlorinated biphenyl levels have decreased since the chemicals, which were used in the paper industry, were banned in the 1970s. The department still recommends that people limit the amount of coho or chinook they eat to one meal per month, but the findings bode well for Lake Michigan, which has a higher concentration of PCBs than the other Great Lakes.