Collette Williams and her son SaVaughn live a few blocks from the Clairton Coke Works. Pollutants from the plant exceed local limits, and Williams believes that exacerbates her son's severe asthma.

U.S. Steel's Clairton plant is the country's largest producer of coke, a key component in making steel.

Dr. Deborah Gentile of Duquesne University with SaVaugn Williams. She helps conduct a twice-monthly asthma clinic inside Clairton's elementary and high school.