And many of these can be equally or almost as harmful as mercury, medical experts say.
Lead, for example, is considered a potent neurotoxin widely considered on par in its harmful effects with mercury. Power-plant emissions of lead nationwide were 132 tons in 2002 - about triple mercury's level, the report's TRI data show. About 153 tons of another nasty metal, chromium, and 62 tons of arsenic were also emitted.
"If the issue is fetal health, and the science is correct that lead and mercury produce similar results, why is the EPA saying it's important to control mercury, but not lead?" asks John Stanton, vice president of the National Environmental Trust and author of the report.
Donna Wright's son Joseph, who was diagnosed with a neurological disorder, has been undergoing medical treatment for heavy-metal poisoning, having tested very high for lead, chromium, arsenic, and nickel. Significant amounts of those toxins are emitted by the Chesterfield Power Station in nearby Chester, Va., although the company says that the quantities aren't as large as reported.
There are other potential sources for the toxins. The couple has paid for a child's mattress without fire- retardant chemicals, done research into mercury contained in children's vaccines, and examined a range of household items for clues as to their son's problem. But Mrs. Wright keeps worrying about the power plant, too.
"We do a lot of gardening," she says. "I can hundreds of quarts of vegetables every summer that I know are pesticide-free. But that particular power plant emits more toxins than any other in the state, so of course air quality is a concern because we also get a lot of rain here. Our concern now has become: 'How healthy is what we're putting up?' Maybe it would be better to go back to canned vegetables."