A toxic chemical that used to be prevalent in construction materials may still be hiding in the walls of thousands of American schools, and experts believe the EPA is doing too little to prevent it from poisoning a new generation of children.
Polychlorinated biphenyls, a family of chemicals better known as PCBs, were commonly used in building materials until 1979, when they were finally banned due to the threat they pose to human health.
But the damage had already been done, according to Al Letson, the host of the Reveal podcast.
