Dr. Janette Sherman is the author of "Chemical Exposure and Disease." She described the St. Lawrence River as a kind of confluence of carcinogens from all around the Great Lakes: "We certainly know that along the St. Lawrence River there's been advisories particularly for pregnant women but for most people not to eat the fish. And we know about some of the studies that have shown a decline in the IQ of children who ate a lot of these or whose mothers ate a lot of the fish."

Cancer Action NY, based in St Lawrence County, organized a teleconference with Sherman and Dr. David Carpenter. He's director of the Institute for Health and the Environment at SUNY Albany. He says these organic pollutants pose special risks because they're so durable. "The problem," says Carpenter, "is they're persistent and they're fat soluble. And so they don't really go away. So if you ate a contaminated meal last night, you're going to have half those contaminants in your body ten years from now."

The New York State Department of Health recently created an online map showing the break down of cancer rates by county. The New York Times reports that health officials across the country are divided over releasing this type of information on carcinogens in the environment. The American Cancer Society says the maps can easily be misinterpreted and the huge amounts of data on chemicals need further study.