Environmental Organochlorine Exposure and Risk of Breast Cancer

Polychlorobiphenyls (PCB’s) and dichlorodiphenyltrichloroethane (DDT) are persistent organic pollutants in the Great Lakes and other aquatic ecosystems. Currently in North America, human exposure to these compounds occurs primarily through the ingestion of contaminated fish, meat and dairy products. Many of these compounds have interacted with the estrogen receptor, but the interactions are complex. Some congeners of both PCB and DDT, as well as other organochlorine pollutants, have weakly estrogenic activity, stimulating estrogen receptors in both animal and human tissue. Yet others of these compounds have anti-estrogenic capacity. Consequences of the estrogenic effect of xenobiotics in wildlife include an altered male:female sex ratio among California gulls exposed to DDT.