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Published in Summer 2004
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Taking stock of mercury air pollution
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By Jamie Bowman
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American Electric Power Company's coal burning power plant in Conesville, Ohio, released 413 kg of mercury into the air in 2001. It ranked 11th in North America. | As evidence continues to mount that mercury is a global pollutant with potentially devastating effects on human and environmental health, a new report by the CEC says that coal-fired power plants are the number one source of mercury air pollution in North America.
According to the trinational organization's annual Taking Stock report on industrial pollution, released in June, 64 percent (43,384 kg) of mercury air emissions in North America came from coal-fired power plants in 2001.
Mercury is typically released into the air when coal is burned to produce electricity at power plants. Once released into the air, mercury may deposit onto the ground or water. Biological processes transform the mercury into a highly toxic form that can build up in fish, ultimately exposing people to mercury when they eat the contaminated fish.
Mercury can have severe toxicity problems, affecting nervous systems, kidney functions and may lead to death. And a recent United States study found about one in 12 women had mercury levels in their bodies above those deemed safe by national authorities.
Despite these health concerns, North American and European governments have shied away from enacting mercury controls. But two Northeast states have changed that. In June 2003, Connecticut passed a law requiring a 90 percent control by 2008 for its coal-fired units. And this May, Massachusetts followed by adopting regulations forcing power plant operators to capture 85 percent of mercury emissions by 2008 and 95 percent by 2012.
"This took some time to get it right," says Dr. Mark Smith of the Massachusetts Department of Environmental Protection, who worked on the issue for over 10 years. One of the obstacles, he says, was an industry perception that mercury emission controls are too expensive. "Costs are frequently overestimated initially and technological innovation—which we in the US are pretty good at, given the proper incentives—typically drive costs down even further."
Now that utilities in these two states must curb mercury emissions or shut down, the technology will come, and will then be adopted elsewhere, he predicts.
"Coal-fired generating units are a large, and growing, worldwide source of mercury emissions," says Smith. "Because mercury can be transported great distances in the atmosphere, aggressive efforts to reduce mercury emissions from this sector are imperative to reducing global mercury impacts."
Currently, the United States is considering several different options at a national level to reduce mercury emissions from coal-fired power plants. And in Canada, Alberta recently proposed cutting mercury emissions 50 percent from individual facilities by 2009. It would be the first mercury-specific target ever set in Canada.
However, Alberta is also planning to add five new coal-fired power plants in the province that will have to fit within the 50 percent reduction target. And while most of Canada's mercury emissions comes from zinc smelting and trash incineration, Taking Stock 2001 showed that Canadian electric utilities still account for over 2,000 kg a year.
Mercury emissions are not solely a North American problem. Luke Trip, manager of the CEC's Sound Management of Chemicals Program, says the world's biggest mercury polluters, China and India, each put out an estimated 250 tons or more a year, compared to an estimated 41 tons in the United States. And North Americans bear some responsibility for Asia's mercury because China and India are huge suppliers of cheap goods used here and manufactured using coal-fired energy.
"North Americans can show leadership in developing technologies, setting an example and demonstrating how reductions can best be accomplished," says Trip. "Through the CEC's North American Regional Action Plan on mercury, we are developing comparable mercury monitoring data across the continent to better provide decision makers with the tools to effect change."
In addition to its North American Regional Action Plan to reduce or eliminate sources of mercury, the CEC funded the first mercury air emission inventory in Mexico, as well as a mercury hot-spots database. And two rainwater monitors, installed two years ago by the CEC and its partners in western and central Mexico, are collecting data to study how much mercury is being deposited from the atmosphere.
Smith says controlling the world proliferation of mercury is not something to put off: "Mercury releases are certainly affecting the food supply to a significant degree. We're creating problems today that our children will have to deal with."
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