The people who breathe the nation's most unhealthy factory air worry about more than just asthma and other respiratory problems. They also want to know if their daily dose of toxic pollution is slowing the academic and physical development of their children.

In the Ohio River Valley along the Ohio-West Virginia border, factories annually send into the air hundreds of thousands of pounds of manganese dust, a heavy metal that can harm the brain and nervous system.

Biologist Dick Wittberg, who heads the mid-Ohio Valley Health Department, has been pressing for years for a full-blown government study to determine if those releases are harming the children in his hometown of Marietta, Ohio.

Several years ago, Wittberg took part in a study that compared Marietta children with those in a similar-sized Ohio town on academic and physical tests. The Marietta kids fared significantly worse.

"We didn't do anything that in any respect proves that this is manganese that has done this, because there are other scenarios that are entirely possible," he said. "But in my opinion, it really points to some environmental problem that is causing some neurological differences, and one has to suspect manganese. Nobody knows for kids how much is too much."

Source: Associated Press