The protection measures were presented by EPA administrator Carol Browner and include a proposal to ban any further discharges of bioaccumulative chemicals of concerns (BCCs) into ‘mixing zones’ in the Great Lakes.

BCCs include mercury, dioxin, PCBs, chlordane, DDT and mirex. Such chemicals have, for decades, been discharged into the Great Lakes to mixing zones where it was thought the chemicals would dilute to safe levels by the time they entered the open waters of the lakes.

Speaking at a meeting of the International Joint Commission for the Great Lakes, Browner admitted that mixing zones pose a threat to human health. “By allowing poisons to gather first in mixing zones, we guarantee that over time they will spread and accumulate throughout the delicate environment of the Great Lakes,” she said.

The EPA attempted to outlaw discharges to mixing zones in 1995, when water quality standards for the Great Lakes were set. But court action by the iron and steel industry led to the mixing zones ban being struck down in 1997.

Indiana, Michigan, Minnesota and Wisconsin have already passed bills eliminating mixing zones for BCCs in the Great Lakes, and the EPA’s current protection proposal will eliminate mixing zones in the states of Illinois, New York, Ohio and Pennsylvania.

In addition to the Great Lakes ban, the EPA has announced a national review of the use of mixing zones for dilution of BCCs.

Acknowledging that mercury air emissions represent a significant impact on Great Lakes’ mercury levels, Browner confirmed the EPA’s intention to reduce such emissions by no later than December 2000. A study of emissions from coal-fired and electric power stations, which account for approximately one-third of all mercury air emissions, has been conducted but the EPA has been required to delay any decision on emission reductions until a further survey is conducted by the National Academy of Sciences next summer.

BCCs are able to accumulate in waters and have been shown to do so in the Great Lakes (see related story).

There are advisories against eating fish from the Great Lakes in all bordering US states and Canadian provinces.

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