According to the EPA, mercury is a toxic, persistent, bioaccumulative pollutant whose primary human health effects are on neurological development. Children exposed through fish consumption and fetuses exposed through their mother's consumption of fish from contaminated lakes, ponds and streams are particularly susceptible. All New England states now have fish advisories to limit the consumption of fresh water fish.
See story on the link between mercury and heart disease in older men
Everglades Mercury Levels Fall Sharply, Study Shows
MIAMI (Reuters) - June, 2004. Mercury levels in the Florida Everglades have fallen
sharply since authorities curtailed waste incinerators and battery manufacturers reduced their use of the heavy metal, university researchers said on Thursday.
After analyzing nearly a century of data from bird feathers, the researchers from the University of Florida said they had proved that dangerously high levels of mercury found in the wetlands in the early 1990s had been caused by local waste incineration.
Mercury levels found in the feathers of birds last year were 90 percent lower than in 1994, following the introduction of new regulations demanding waste incinerators install pollution-cutting scrubbers on their smoke stacks, said Peter Frederick, an associate professor of wildlife ecology at the university's Institute of Food and Agricultural Sciences.
"This is a triumph of regulation, which is something you don't hear about very often," Frederick added.
The study found it took about seven years for mercury levels in the birds to decline after emissions were curtailed.
The fall in mercury levels also coincided with the voluntary phasing out in the 1980s of the use of mercury by some major battery manufacturers, which cut the amount of toxins in household waste, the researchers said.
The University of Florida findings could play a part in a national debate over mercury emissions from coal-fired power stations in identifying local sources of pollution, rather than global sources, as the main reason for mercury contamination.
Environmentalists, and some U.S. states, accuse the Bush administration and the Environmental Protection Agency of not enforcing the Clean Air Act, and abandoning strict controls on mercury emissions from power plants.
Florida has few coal-fired power plants and gets most of its electricity from nuclear power, which is why waste incinerators ranked as the main source of Everglades mercury contamination.
Mercury is a toxin that causes reproductive and behavioral problems in birds. The metal also is toxic to humans, and can cause serious neurological damage.
The University of Florida study said populations of wading birds in the Everglades dropped by 90 percent between the 1950s and the 1980s, and high mercury levels played a part. The numbers of breeding pairs in the marsh in the last five years were higher than they had been in the previous 30 years.
The findings appear in the June issue of the journal Environmental Toxicology and Chemistry.
Mercury Rules Work, Study Finds
EPA, Florida Cite Emissions Regulations
By Eric Pianin
Washington Post Staff Writer
Thursday, November 6, 2003
A decade-long study of southern Florida and the Everglades concludes that tough regulations of airborne mercury emissions have a profound and almost immediate effect in removing the toxic pollutant from the environment and the food chain.
The findings, according to some environmentalists, offer compelling evidence that government regulators can effectively and relatively swiftly address public health problems associated with mercury, a byproduct of burning coal and waste. Mercury in water turns to methylmercury, a potent neurotoxin that can cause severe neurological and developmental damage in humans -- especially small children -- and that comes primarily from eating contaminated fish and shellfish.
The $40 million study by the state of Florida, the Environmental Protection Agency and the U.S. Geological Survey also adds to evidence of a link between mercury emissions -- especially from incinerators and power plants -- and water-quality problems that lead to toxic buildups in fish, waterfowl and other wildlife.
The report, to be released today in Tallahassee by Florida environmental officials, concludes that strict government controls of emissions can produce dramatic improvements in much less time than scientists once assumed. The levels of mercury contaminant found in largemouth bass and other wildlife of the Everglades declined by 60 to 75 percent since state and federal agencies began waging an aggressive campaign in the early 1990s to close or modernize municipal and medical-waste incinerators that emitted mercury gases.
Industry advocates and research groups, including the Edison Electric Institute and the Electric Power Research Institute (EPRI), contend that mercury pollution is globally ubiquitous -- carried around the world by the wind -- so that forcing power plants to install costly antipollution equipment would not necessarily ensure a reduction in emissions.
"EPA and EPRI research suggest that 40 to 70 percent of mercury pollution comes from outside our borders," said Dan Riedinger, a spokesman for the Edison Electric Institute. "There's limits to the benefits that can be derived from greatly reducing the mercury emissions from any sector in the United States."
The Florida study is the latest entry in a national debate over whether mercury emissions should be controlled in the utility industry, which generates a third of the nation's atmospheric mercury pollution. The EPA faces a Dec. 15 deadline for announcing a proposed rule that for the first time would control mercury and other hazardous emissions from the nation's 1,100 coal- and oil-fired power plants.
The EPA announced last year that it was considering a rule under the Clean Air Act ordering utilities to meet a "maximum achievable control technology" (MACT) standard for mercury that would require every plant that exceeds the standard to install expensive scrubbers or face penalties. The plants would not be allowed to buy "credits" from lesser-polluting companies to meet the new targets, as they may under clean-air rules regulating acid rain. The new MACT rule potentially could add $6 billion a year to industry's operating costs and reduce mercury pollution by as much as 90 percent by 2008 -- from 48 tons a year nationwide to five tons.
The utility industry and its congressional allies have urged the administration to soften the proposed rule or delay its implementation beyond a 2007 target date. Industry officials say they do not oppose new standards but want them drafted in a way to give the utilities flexibility to reduce emissions as new technology becomes available "without compromising reliability."
As a compromise, President Bush included provisions in his "Clear Skies" bill that would require smaller reductions of mercury pollution over a longer period of time. The measure has stalled in Congress. A House Science subcommittee heard expert testimony yesterday that was described by lawmakers as "compelling evidence" of the need for action on mercury.
Richard Ayres, an environmental lawyer in Washington, said the Florida study "demonstrates that reducing emissions from power plants would have almost an immediate effect on improving the environment and the public health."
Swedish researchers once thought it could take hundreds of years for mercury contamination of the environment and the food chain to abate. A report issued last week by the Northeast States for Coordinated Air Use Management estimated that toxic mercury emissions from power plants could be reduced by 90 percent with regulation and commercially available technology.
The Florida study determined that the vast majority of the mercury deposited in Florida's aquatic life and wildlife came directly from local or regional incinerators and plants.
"It is true there is one atmosphere, and some of the mercury comes from other sources, but the local signature is substantially greater than the mercury that comes from far away," Thomas D. Atkeson, a mercury expert and coordinator of the research, said in an interview last week. "It is clear that to the extent you can lower the emissions of reactive mercury in your airshed, you will see the benefit in your local area -- and you will see it relatively quickly."