Persistent organic pollutants, made by nature

Abstract

Christopher Reddy vividly remembers the first time he heard about a perplexing organohalogen compound found by researchers in seabird eggs along the Pacific and Atlantic coasts, as well as in the Great Lakes region. He was sitting in the audience at an American Chemical Society meeting in the late 1990s listening to Sheryl Tittlemier, then a graduate student at Carleton University, present her findings. Structurally, the halogenated bipyrrole discovered by the Carleton team resembled polychlorinated biphenyls (PCBs), a class of synthetic molecules used as coolants, stabilizers, insulators, and flame retardants whose production was banned in the U.S. in the late 1970s because of concerns over their toxicity and persistence in the environment. But there was no record of this particular compound having ever been synthetically produced. Tittlemier, now a scientist at the Canadian Grain Commission, said she suspected the compound might be a natural product (Environ. Sci. Technol. 1999, DOI: