Groups like the Environmental Defense Fund and Center for Biological Diversity have warned that dispersants, especially Corexit, used on oil in the Gulf of Mexico are dangerously toxic to marine life. Then we have this today from EPA, as reported by USA Today:

Dispersants used to battle the Gulf of Mexico oil spill don’t appear to interfere with reproduction, development and other biological processes in marine life, concludes a study by the Environmental Protection Agency reported Wednesday….

The tests looked at how toxic the dispersants are to cells. Among eight dispersants evaluated, Corexit was in the middle in terms of toxicity, says Richard Judson of the National Center for Computational Toxicology and lead author on the paper. “But in the big scheme of things, none of them was very toxic,” he says….

Because the tests are not done on living animals, but on cells, they’re not definitive as to what’s happening in the marine environment, says John Giesy, Canada Research chair in environmental toxicology at the University of Saskatchewan in Saskatoon, Canada.

He says concern about dispersants in an environmental catastrophe of the magnitude of the oil spill is “a little bit of a red herring.” The oil is the problem because of its ability to coat and kill, he says. Dispersants thin and break it up, better allowing sunlight and bacteria to decompose it. Dispersants “are the lesser of two evils,” he says.

But no one asked Keith Olbermann!