PCBs

PCBs demonstrate a clinical toxicity that is very similar to that seen with methylmercury. Neurological problems and reproductive problems are prominent toxic effects. Children born of sufficiently exposed mothers had increased prematurity, growth retardation, decreased intelligence, and less efficient nerve function. Great Lakes fish have long been contaminated with PCBs. In the 1960s, it was first noted that these noxious chemicals accumulate in the fish. It was then noted that the fish-eating birds in the Great Lakes area also exhibited reproductive problems. Further analysis led to the dis­covery that literally hundreds of different chemical contaminants maintained a presence in the fish. It wasn't really formally recog­nized until the late 1980s that humans were accumulating these con­taminants as well. In retrospect, this should not have been so amazing. After all, you literally are what you eat. If you are at the top of the food chain, you are the repository of all of the bioaccu-mulation that takes place below you.