Polychlorinated biphenyls are synthetic organic (carbon-based) compounds
which were used in electrical fixtures, machinery, plastics and inks. Over 1.5 billion pounds of PCBs were
manufactured between their invention in 1929 and implementation of a government ban in 1977. They cause cancer
and other adverse health effects in lab animals and are thought to result in similar problems in humans.
Today, the major sources of PCBs are environmental reservoirs remaining from periods of
significant use. PCBs move easily from air to soil and water and thus have been distributed around the globe.
PCBs pose environmental problems because they are persistent and because they accumulate in the bodies of aquatic
organisms such as fish. Government advisories recommend that we avoid eating certain fish from specific bodies of
water (see EXPLORE), e.g. carp and catfish from the Saginaw River in Michigan.
Another group of industrial chemicals of environmental concern is PBDEs (Polybrominated Diphenyl Ethers).
Their structure is similar to PCBs with bromine replacing the chlorine atoms. PBDEs are used as flame retardants in
furniture and electronics. These chemicals, presently banned in Europe, have many of the same properties and potential
health effects of PCBs and are present in the air, water and biota of the Great Lakes.
Michigan Fish Advisory
PCBs in Manistique Harbor
PCBs Global Transport