It has long been assumed that high mercury levels in animals and plants was a problem associated with aquatic ecosystems, so researchers were surprised to find high levels of the toxic element in forest-dwelling animals. The findings, released last week by the Maine-based BioDiversity Research Institute, highlight the need for strong mercury emissions regulations.

Maine officials have long complained that Maine’s lakes and rivers – and the fish that live in them – are being poisoned by mercury that is blown into the state from power plants and manufacturing facilities to our south and west. Collecting and analyzing data from the northeastern United States and eastern Canada, scientists working with the BioDiversity Research Institute have confirmed this scenario. In fact, the researchers identified nine mercury “hot spots,” places with high concentrations of mercury, in the region. Four of them are in Maine.

One, Midcoast Maine, has high mercury levels because the metal was carried down the Penobscot River from the HoltraChem plant in Orrington, which used mercury in the process of making chlorine. The others, however, are far from facilities that use mercury, suggesting the metal is blown in from elsewhere before settling into the water and ground.

The other Maine hot spots are the upper Penobscot River, Down East Maine and the Rangeley Lakes region. Scientists were surprised to find forest-dwelling birds with high levels of mercury in their blood. The birds with the highest mercury concentrations were found in the mountains of western Maine and southern Quebec. This confirms that airborne mercury is a serious threat, even before it settles into water and sediment.

As further evidence, a research facility in northern Vermont recorded high mercury readings during weather patterns that brought in air from the south and southwest where manufacturing facilities and power plants are most prevalent.

The good news is that mercury emissions have declined 40 percent since 1990. Most of this reduction has come from strong regulation of municipal and medical waste incinerators. Under Clean Air Act standards, these facilities were required to reduce emissions levels by more than 90 percent. A similar requirement for coal-fired power plants, supported by Maine’s senators, has stalled in Congress and mercury emissions from these facilities are relatively unchanged.

A Bush administration proposal, which is also included in its Clear Skies initiative, would require a 70 percent reduction in mercury emissions by 2018 even though officials at the Environmental Protection Agency have said a 90 percent reduction by 2010 is possible. More recently, the agency’s inspector general said that the mercury rules should be re-evaluated because they were crafted to meet target goal supported by industry. And, last week, the Government Accountability Office said the economic analysis of the administration’s rules was flawed.

By court order, the agency is supposed to have rules for mercury emissions in place by tomorrow. The agency has little rationale for sticking with the 70 percent reduction in light of the GAO and IG findings and the failure of a congressional committee this week to get enough votes to move the entire Clear Skies package forward.

This study is the latest evidence that the administration’s rules are too lax and that Congress should instead move ahead with tougher rules like those championed by Maine’s delegation.