What are polychlorinated biphenyls (PCBs) and the health effects?
Polychlorinated biphenyls (PCBs) are a family of related chemicals with a complex but very stable molecular structure. There are 209 different chemical configurations included in this family. PCBs do not have distinguishing features that make them easily recognizable, and can be detected only by laboratory analyses. They are practically insoluble in water but are very soluble in fats, waxes, and oils. They are not volatile so they do not evaporate and they do not degrade readily. The result is that they accumulate, particularly in animal fats and in sediments of lakes, rivers, and streams. Beginning in the 1920’s, PCBs were used in electrical components, as lubricants, in hydraulic fluids, as heat transfer fluids, and in coatings, plastics, and inks. PCBs are components of many industrial materials even today, though their manufacture and distribution was curtailed in the late 1970’s. PCBs were extremely useful because of their low electrical conductivity, heat absorption capacity, and
