Mercury more widespread in Great Lakes than thought

The Great Lakes are the largest freshwater resource in the world. They provide water, food, recreation, employment and transportation to more than 35 million people and they have suffered mercury pollution since 1850.

Charles Driscoll, Syracuse University professor at the L.C. Smith College of Engineering and Computer Science, presented findings from the Great Lakes Mercury Connections report, a composite of 35 research projects, in Detroit Tuesday morning. SU graduate student Joe Denkenberger and SUNY-ESF grad student Xue Yu contributed research to the composite study.The report encompasses the lakes and surrounding land from Minnesota to Vermont, in both the U.S. and Canada and discusses causes, impacts and solutions to the mercury problem.

Their findings revealed that mercury levels in the Great Lakes and its inhabitants has dropped significantly from the high 1985 levels, but has spread and amplified in effected organisms due to biological phenomenon.

Background on Mercury

Mercury is a naturally occurring element in the universe. It's present in the soil and air naturally. However, coal mining operations, incinerator, coal-fired power plants and other industrial operations emit unnaturally high concentrations of mercury to the air, and thus to the water, soil and all organisms living in the ecosystem. As Driscoll points out, 1/3 of mercury in the region occurs naturally, while fully 2/3 is from anthropogenic causes.

Mercury starts at a "lower" level in microorganisms like algae and amplifies to large quantities as it moves up the food chain to fish, birds and the humans that eat them. Mercury causes reproductive problems in simpler organisms and can negatively impact intelligence and cognitive activity in vulnerable human populations, such as young children and women of childbearing age.

A simplified mercury cycle showing how mercury enters and cycles through ecosystems, biomagnifies up the food web, and bioaccumulates in fish and wildlife. (Graphic courtesy of Great Lakes Mercury Connections)

The Study

Driscoll, along with James Weiner, professor at University of Wisconsin-La Crosse, and executive directors from the Great Lakes Commission and Biodiversity Research Institute, discussed major points from the three-year study:

• From 1850-1985, mercury levels in the Great Lakes increased seven-fold during industrialization
• From 1985-today, levels have dropped 20 percent due to environmental regulations on incinerators and cola mining operations
• 60 percent of fish in the area have measured levels of mercury above EPA-safe levels

The Implications

Driscoll hopes that the U.S. Environmental Protection Agency will take notice as it nears the November deadline for the Utility Air Toxics Rule, a set of regulations that will require coal-fired power plants to control mercury emissions. In the wake of the House passing the Transparency in Regulatory Analysis of Impacts on the Nation (TRAIN) Act, a move that introduces economic concerns to environmental controls and repeals many provisions of the Clean Air Act, the EPA's decision may make-or-break the Great Lakes region's recovery from mercury pollution.

With the EPA analysis of mercury reduction finding a 13:1 ratio of benefit-to-cost, this seems like a no-brainer decision. However, because a large number of fish consumers in the area are of lower socio-economic status, the decision may come down to an environmental justice issue.

"I suspected that the problem was more widespread that we imagined," said Driscoll, who has been studying the Great Lakes since the mid-1980s. While he is hopeful in the decrease of mercury levels already seen, Driscoll also worries about the EPA's decision later this year. After 15 years on the table, the decision to regulate mercury emissions from coal-fired power plants may decide the fate of Great Lake's region.