PCBs were widely used for decades until it was realized they posed serious health threats. Bans stopped their use, but their presence remains. In 2009 General Electric began dredging PCBs from the Hudson River.
As the first phase of the PCB clean-up draws to a close, Dr. Bill Chameides, dean of Duke's Nicholas School of the Environment, gives the PCB backstory from the lab to the manufacutring plant. Then Duke alum David Rosoff picks up the story, explaining A to Z of the Hudson River dredging project.