Dioxins, a class of compounds that are byproducts of pesticide manufacture, have had a particularly fatal reputation following the evacuation of New York's Love Canal community in the late 1970s and the Missouri town of Times Beach in 1983. A San Francisco television news show dubbed it "a synthetic chemical so powerful that an ounce could wipe out a million people." Ralph Nader gave a more conservative estimate—that three ounces could wipe out the same number of people. The Washington Post declared, "The evidence is overwhelming that dioxin is carcinogenic in humans," and other journalistic sources dubbed it "the most toxic chemical created by man." Dr. Irving Selikoff (also a proponent of the widespread removal of asbestos insulation from buildings that was soon found to be far more hazardous than leaving it in place) told Time magazine in 1983: "No doubt about it, dioxin is harmful to humans. It is man-made. As a result, the human body doesn't know how to break it down [sic]. We store it in our bodies and accumulate it [sic]."
It turns out that dioxin is indeed fatal in tiny doses—but only to guinea pigs. Hamsters, on the other hand, can tolerate a dose about 1,900 times as high before achieving the same mortality rate. A test on prisoners found that a dose proportionally 100 times as high caused chloracne, a mild skin condition. Likewise, a huge industrial accident in the Italian town of Seveso in 1976, which exposed its residents to a cloud containing about 4 pounds of dioxin, resulted only in temporary cases of chloracne and nausea. In no case have epidemiologists detected an increase in the incidence of cancer, birth defects, or any other health problems among those exposed.
The EPA has now revised dioxin's safety threshold dramatically downward, calling into question the recent decision to evacuate Escambia. In 1991, Vernon N. Houk, the official who originally ordered the evacuation of Times Beach, said that he would not have done so had he known then what he since learned about dioxin. Home buyers eagerly bought up the vacated Love Canal properties, but Times Beach is still surrounded by a large fence to keep out trespassers, inside which wildlife flourishes.