For 3 decades starting in the 1940s, General Electric dumped solvents from its manufacturing facilities into New York’s Hudson River, contaminating it with polychlorinated biphenyls (PCBs). Scientists worried about how best to clean up the pollutants. “At that time, they thought PCBs were completely nonbiodegradable,” says Lawrence P. Wackett, a biochemist at the University of Minnesota Twin Cities who consulted for the company in the late 1980s.
But analysis of sediment cores extracted from the river throughout the 1980s showed that the PCBs were slowly losing their chlorine atoms and turning into benign hydrocarbons. Later, scientists determined that the transformation was performed by microbes. Read more…