Study: No U.S. fish is free of mercury pollution

No. U.S. stream is uncontaminated by mercury pollution, according to a new analysis by the U.S. Geologic Survey. That means wild fish caught in even the most pristine streams may be tainted with unsafe levels of a potent neurotoxin that can attack the developing brains of children, leading to permanent damage.

The analysis shouldn't be surprising. Most states and the Environmental Protection Agency warn people against eating certain types of fish from certain bodies of water because of high mercury levels. But the fact that contamination is so widespread is nonetheless a wakeup call. The Bush Administration attempted a -- flawed, according to critics -- effort to regulate mercury from coal-fired power plants, but it was struck down in court. The EPA has only recently taken seriously the mercury spewed by cement kilns, another major source.

In 291 streams tested, all fish were contaminated to some degree. About one in four had mercury at levels exceeding the safe human consumption limits set by the EPA, and most exceeded the safe wildlife consumption limits for fish-eating mammals.

"This study shows just how widespread mercury pollution has become in our air, watersheds, and many of our fish in freshwater streams," said Secretary of the Interior Ken Salazar. "This science sends a clear message that our country must continue to confront pollution, restore our nation’s waterways, and protect the public from potential health dangers."

It's also a reminder that carbon dioxide is not the only pollutant of concern from power plants. Coal-fired power plants are the single largest source of airborne mercury pollution, and they also contribute to smog and acid rain. The oldest power plants -- those built and in operation before the Clean Air Act took effect -- are the most highly polluting and yet they escape many of the new regulations on pollution. Gold and mercury mining also contributed to the contamination of at least 59 of the streams studied.

Mercury pollution starts in the air, as burning coal, mining gold or making cement -- among other industrial processes -- kicks up mercury through smokestacks and into the air. But airborne mercury isn't a great concern; when it falls out, it contaminates water, enters the food chain and makes popular game and commercial fish dangerous to eat. Children, and women who are nursing, pregnant or who may become pregnant are cautioned not to eat certain kind of fish, so as to avoid interrupting the development of the brain. Exposure can cause permanent brain damage. (That's why states, led by New York, want the Environmental Protection Agency to use the Clean Water Act to fight mercury smokestack pollution.)

While mining -- especially gold mining -- produces the most mercury pollution in the U.S., the largest sources of mercury air pollution are mainly coal-fired power plants. Here's a list of the largest polluters of mercury to the air, according to the Environmental Protection Agency's Toxic Release Inventory:

Top 10 sources of mercury air pollution in the U.S.

1. Ash Grove Cement Co.'s cement kiln in Durkee Ore., is one of nine plants owned by the Kansas-based company. Its Kansas kiln also makes the list of top 100 air polluters of mercury (No. 64). The EPA has only recently started cracking down on mercury pollution from cement plants.

2. Alabama Power Co.'s Miller Steam Plant in Jefferson, Ala. is a coal-fired power plant. Alabama Power is a subsidiary of Atlanta-based Southern Company, one of the largest utilities in the U.S., which generates 68% of its electricity from burning coal. Also on the Top 100 list of mercury air polluters are Georgia Power's Monroe, Ga. plant (No. 5) and Alabama Power's Gaston (No. 9) and Greene, Ala. plants (No. 81).

3. Luminant's Martin Lake Steam Electric Station and Lignite Mine in Rusk, Texas, is a coal-fired power plant. Luminant is a subsidiary of Energy Future Holdings, formerly TXU Corp., a big Texas energy company. Other Luminant plants on the top mercury air polluter list include its Monticello Plant in Titus (No. 4), its Big Brown plant in Freestone (No. 7) and its Sandow plant in Milam (No. 43)

4. Luminant's Monticello Steam Electric Station and Lignite Mine. See No. 3.

5. Georgia Power's Scherer Steam Electric Generating Plant in Monroe, Ga. See No. 2.

6. Ameren's Labadie Power Plant in Franklin, Mo. is a coal-fired power plant. Ameren is based in St. Louis and has other plants on the Top 100 list: Its Rush Island plant in Jefferson, Mo. (No. 49), its Newton plant in Jasper, Ill. (No. 49), its Meramec plant in St. Louis (No. 73) and it's Sioux plant in St. Charles, Mo. (No. 75).

7. Luminant's Big Brown Steam Electric Station and Lignite Mine in Freestone, Texas. See No. 3

8. NRG's Limestone Electric Generating Station, a coal-fired power plant in Jewett, Texas. It is one of 12 coal-fired power plants and dozens of other power plants owned by NRG. Also on the Top 100 mercury air polluters is NRG's Big Cajun II plant in Pointe Coupee, La. (No. 23).

9. Alabama Power's Gaston Steam Plant in Shelby, Ala. See No. 2

10. Alcoa's Calhoun, Texas plant makes alumina, which is used to make aluminum. Alcoa, based in Pittsburgh, is among the world's biggest manufacturers of aluminum.

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• The Dirty Dozen: 12 Foods to Eat Organic
• The Clean 15: Foods Free of Contamination
• The Sexy Barramundi: Sustainable Fish Recipes
• Nine Facts About Ocean Conservation
• Seven Safe Eco-Friendly Fish Recipes

Reprinted with permission of Hearst Communications, Inc