Coal-fired power plants will have to start trading mercury emissions in an effort to cut down on the heavy metal that’s been known to bioaccumulate in fish and people. Now there’s evidence that makes this goal all the more urgent. Researchers at the University of Texas found a link between the mercury that comes out of smokestacks, and the rate of autism in Texas schools. Host Steve Curwood talks with one of the study’s authors, Dr. Claudia Miller.