The highly toxic PBB poisoning of Michigan remains the most widespread chemical contamination known in U.S. history. The Poisoning of Michigan is an investigative journalist's account of the contamination of Michigan's dairy cattle with the highly toxic chemical PBB (polybrominated biphenyl) in 1973. A near relation of PCB, this now-banned substance, designed as a fire retardant, was mistaken for a nutritional supplement at a chemical plant...