Industrial pollution, especially from coal-fired power plants, is the main source of mercury emissions into the environment.

Industrial boilers, chlorine production and the burning of hazardous waste also contribute to airborne mercury pollution. Mercury is a naturally occurring element; some airborne mercury comes from the earth, from sources such as volcanic eruptions and erosion.

Mercury in the air can disperse over wide areas, far from the source of pollution. It eventually settles onto soil and into lakes, rivers and the ocean. Bacteria in these water sources convert this inorganic mercury into an organic compound called methylmercury.

For more information, log on to these Web sites:Food and Drug Administration:

(http://www.fda.gov)

Environmental Protection Agency:

(http://www.epa.gov)

Environmental Defense:

(http://www.environmentaldefense.org)

Natural Resources Defense Council:

(http://www.nrdc.org)

National Fisheries Institute:

(http://www.nfi.org

For Oregon, local fish advisories can be found at

(http://www.dhs.state.or.us/publichealth/fishadv/docs/fishadv.pdf).

For Washington state, a list of local fish advisories can be found at

(http://www.doh.wa.gov/ehp/oehas/EHA_fish_adv.htm).Freshwater and ocean fish absorb this type of mercury when they eat other aquatic organisms such as algae and plankton. The higher the fish is on the food chain, the more mercury they absorb. Predator fish such as shark, swordfish and fish-eating whales have the highest concentrations of mercury in their bodies. In general, as fish become larger and older, mercury concentrations in their bodies increase.

Fish-eating mammals such as otter and mink, and birds such as eagles and osprey, also tend to have high levels of mercury. Human levels of mercury depend on the type and amount of fish an individual eats on a regular basis. Animals and humans all accumulate mercury faster than the body can eliminate it.

Mercury in fish is found in the meat itself, so removing the skin and fat does not lower the mercury content. (However, removing the skin and fat from fish does reduce the amount of other contaminants, such as dioxins and PCBs.) Cooking does not have any effect on mercury levels.

Mercury is also found in some thermometers, older blood pressure devices, barometers, batteries, fluorescent lights and dental amalgams for fillings. However, these are rarely significant sources of mercury for humans, and are generally a concern only for those who have occupation exposure to elemental mercury.

In the last decade, the EPA began regulating medical and municipal waste combustion. This has substantially decreased the amount of mercury pollution from these sources. Also, mercury use in manufacturing in the United States is now tightly regulated.

The regulation of coal-fired power plants is being hotly debated. About 40 percent of airborne mercury pollution – 48 tons annually – comes from these utility plants.

In 2000, the Clinton administration declared mercury a toxic substance subject to regulation under the Clean Air Act. The EPA was directed to propose standards for utility plant emissions by the end of 2003, with the goal of reducing mercury emissions by as much as 90 percent – down to just 5 tons annually – by 2008.

Coal and utility industry representatives argue that strict emission regulations for the nation’s 1,100 coal-fired plants would be too costly. They claim this would drive up the price of electricity, and lead to higher costs for heat, food and consumer products.

The Bush administration’s Clear Skies plan has backed down from the stringent requirements of the Clinton plan. Officials are now calling for a cap on emissions to be set at 34 tons in 2010, with an overall goal of reducing mercury emissions by 70 percent by 2018. Mercury would no longer be regulated as toxic substance requiring maximum pollution controls.

On March 16, the Los Angeles Times reported that some EPA staffers claim the White House developed the new emissions rule with input from the coal and utility industries. They say the EPA’s usual scientific and economic studies were not done before arriving at this decision.

Environmental Defense analyst Michael Shore believes that the EPA’s decision on mercury “will fly in the face of good public health policy. It’s a bad ruling and there’s nothing collaborative about it.”