Minnesota Pollution Control Agency

Contact: Sam Brungardt, 651-282-6410 Toll-free: 1-800-657-3864 St. Paul, Minn. -- When it comes to mercury pollution, we're all in it together. That's the assessment of two Minnesota scientists who participated on international panels that reviewed what is known about mercury pollution and its effects. The panels' summaries of scientific understanding were published today in the Swedish science journal "Ambio." The mercury pollution of Minnesota water bodies and the fish in them is a result of mercury being released to the atmosphere around the world, say the two scientists, Daniel Engstrom, Ph.D., of the Science Museum of Minnesota, and Edward Swain, Ph.D., of the Minnesota Pollution Control Agency. Engstrom and Swain have developed mercury expertise during the past 20 years through their cooperative research on mercury pollution, including ongoing research on the factors that control the contamination of fish with methylmercury. "Because mercury is transported by wind around the globe, what is done in one country to control mercury emissions affects other countries," Swain said. "For example, recycling mercury will accomplish little globally if that mercury is bought and used elsewhere in such a way that it pollutes the atmosphere. That's why countries must consider not only the local impacts of their mercury-control policies, but the impacts on other countries as well." The reviews that Engstrom and Swain participated in were coordinated by the organizers of the Eighth International Conference on Mercury as a Global Pollutant, held last August in Madison, Wis. Engstrom was one of nine panelists from four countries who reviewed what is known about the sources of atmospheric mercury deposition to aquatic systems. "Our panel confirmed some of the work first published from research on Minnesota lakes -- that, on average, three times more mercury now falls from the sky than before the Industrial Revolution," Engstrom said. "Interestingly, one of our findings is that the amount of mercury in the global atmosphere has not changed over the past few decades despite decreased emissions in developed countries; our decreased mercury emissions have been offset by increased emissions from developing countries around the world, particularly those in Asia." Swain was chairman of a nine-member panel of scientists from five countries who summarized the socioeconomic effects of mercury pollution. "The mobilization of mercury from deep geologic stores, such as ore deposits and coal, into the biosphere has had many negative consequences," Swain observed. "Our panel concluded that reduction policies should take a global perspective. Although the burning of coal is responsible for the majority of mercury emissions, we in developed countries need to be more aware of mercury as an international commodity. For instance, as we have eliminated the use of mercury in manufacturing and products, such as paint, thermometers, thermostats and batteries, developing countries have increasingly been the recipients of the mercury we reclaim or no longer use. Mercury use in developing countries not only causes local harm, but also results in the mercury eventually returning to us via the atmosphere." "The Madison Declaration on Mercury Pollution," a state-of-the-science document that stems from the findings of the expert panels that assembled at the conference in Madison last August, was also published in the same issue of "Ambio." The declaration presents 33 principal findings from the five papers prepared by the panels of mercury scientists. The papers summarize what is presently known about the sources and movement of mercury in the atmosphere, the socioeconomic and health effects of mercury pollution on humans, and mercury's effects on the world's fisheries and wildlife. Key findings in the declaration were:

• On average, three times more mercury now falls from the sky than before the Industrial Revolution 200 years ago.
• Unregulated use of mercury in small-scale gold mining is polluting thousands of sites around the world, posing long-term health risks to an estimated 50 million inhabitants of mining regions and contributing more than 10 percent of the mercury in Earth's atmosphere attributable to human activities.
• The health risks posed by methylmercury-contaminated fish warrant a general warning to the public - especially children, women of childbearing age and pregnant women - to be careful about how much and which fish they eat.
• Little is known about the behavior of mercury in marine ecosystems and the contamination of marine fishes by methylmercury, the ingestion of which is the primary way most people at all levels of society worldwide are exposed to this highly toxic form of mercury.
• There is solid scientific evidence of methylmercury's toxic health effects, particularly on the human fetus.
• To increase the benefits and reduce the risks, consumers should choose fish with high levels of omega-3 fatty acids and low levels of methylmercury.
• The actual socioeconomic costs of mercury pollution are probably much greater than estimated because existing economic analyses do not consider mercury's impacts on ecosystems and wildlife.
• Methylmercury levels in fish-eating birds and mammals in some parts of the world are reaching toxic levels, which may lead to population declines in these species and possibly in fish as well.
• The concentration of methylmercury in fish in freshwater and coastal ecosystems can be expected to decline with reduced mercury inputs; however, the rate of decline is expected to vary among water bodies, depending on the characteristics of a particular ecosystem.

"The Madison Declaration summarizes a year-long effort by many of the world's leading mercury scientists to review mercury science findings," said James Wiener, Ph.D., a Wisconsin Distinguished Professor at the University of Wisconsin-La Crosse and technical chairman for last summer's conference. "The policy implications of these findings are clear. The declaration and the detailed analyses of the five supporting papers clearly demonstrate the need for effective national and international policies to combat the environmental mercury problem."