Some environmentalists opposed to President Bush's re-election are focusing on mercury emissions (search), charging that coal-burning U.S. power plants pollute, poison seafood and threaten children.

"The science is clear on this issue. Mercury pollution is a serious problem. It's something we feel the public has a right to know about and, frankly, it's something the public should be outraged about when it looks at what the Bush administration is doing," said Sara Zdeb of Friends of the Earth (search).

But some scientists question the link between low levels of mercury and developmental disabilities.

There "are significant misrepresentations of what is available in the way of credible and generally accepted evidence in the scientific and medical literature," said Dr. Jack Snyder of the National Library of Medicine (search).

Snyder said that "more than 99 percent of the world's mercury" doesn't come from U.S. power plants.

Bush first earned scorn from environmentalists on the issue when his administration reduced to 70 percent the Clinton administration's proposed 90 percent reduction in power plant mercury emissions. That plan was offered two days after Bush won election in 2000.

Click here for a complete report by Fox News' William La Jeunesse.