Techniques to Age Date Human Exposure to PCBs Check Access

PCBs were first produced in 1929 and were widely used throughout the 20th century for a variety of industrial uses such as dielectric fluids, hydraulic fluids and plasticisers. Production rates decreased steadily throughout the 1970's as the health and environmental risks from PCBs began to be better understood. In the United States this resulted in passing of the Toxic Substances Control Act in 1976, with PCBs phased out from 1979. However, PCBs can still be found in closed systems such as dielectric fluids in electrical equipment. They are highly persistent and still routinely found in environmental and human samples across the globe. All humans have been exposed to background concentrations of PCBs, however, there are also events where individuals are exposed to elevated concentrations. In litigation cases it is important to differentiate specific exposure events from background exposure, as well as identifying the source of contamination and age dating the exposure period. Age dating PCB exposure is complex, but assessments can be made because different PCB congeners have different residence times in the human body.