Mercury pollution in the Great Lakes region—nearly forgotten, but not gone

Springer

New York, 11 October 2011

The scope and intensity of mercury pollution in the Great Lakes region is much greater than previously reported, but additional mercury controls should bring needed improvement, according to a new summary of scientific research on the subject.
Despite general declines in mercury levels in the Great Lakes region over the past four decades, mercury concentrations still exceed human and ecological risk thresholds, especially in inland lakes and rivers, according to the report Great Lakes Mercury Connections: The Extent and Effects of Mercury Pollution in the Great Lakes Region, published in Springer’s journal Ecotoxicology. Also, new research indicates that for some species of fish and wildlife in particular areas, mercury concentrations may again be on the rise.

While the risk of elevated mercury concentrations to human health is well known—all of the Great Lakes states and the province of Ontario issued fish consumption advisories due to high mercury—new studies cited in the report suggest that adverse effects of mercury on the health of fish and wildlife occur at levels much lower than previously reported.
“The good news is that efforts to control mercury pollution have been very beneficial,” says David C. Evers, Ph.D., executive director and chief scientist at Biodiversity Research Institute, and the principal investigator in the Great Lakes study. “However, as we broaden our investigations, we find that fish and wildlife are affected at lower mercury concentrations and across larger areas, and that impacts can be quite serious. For example, we found that estimated mercury concentrations in the blood of common loons were above levels that are associated with at least 22 percent fewer fledged young in large areas of the Great Lakes study region.”

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