Jarman: It took a lot of foresight to ban DDT.

Narrator: This is Science Today. Researcher Wally Jarman of the University of California, Santa Cruz says that a generation after it was banned, DDT is still found in the tissues of many wild animals. The ban was hotly argued at the time the law was passed.

Jarman: In 1972 there were definitely problems associated with it, but it took foresight and it took some push to get it banned, and now we're still seeing, 25 years later, we're still seeing problems associated with it.

Narrator: Peregrine falcons were only barely saved from extinction, and some eagles are still affected. Jarman says that if lawmakers at the time hadn't looked to the future, the consequences would have been even worse.

Jarman: And one of my worries now is that people are becoming a little more lackadasical about environmental laws, and I think a good example of a good law was what happened with DDT. I think it's really important for people to keep that in mind, that sometimes you don't see the immediate effects. And that maybe the damage you've already done -- if they wouldn't have banned it, who knows what would have happened? We may have lost peregrine falcons completely.

Narrator: For Science Today, I'm Steve Tokar.