QUOTE : Intuitive toxicology is the term that Slovic uses for the way most people assess the risk of chemicals. His research reveals that this approach is distinct from the methods used by toxicologists, and that it tends to produce different results. For toxicologists, “the dose makes the poison.” Any substance can be toxic in excess. Water, for instance, is lethal to humans in very high doses, and overhydration killed a runner in the 2002 Boston Marathon. But most people prefer to think of substances as either safe or dangerous, regardless of the dose. And we extend this thinking to exposure, in that we regard any exposure to chemicals, no matter how brief or limited, as harmful. In exploring this thinking, Slovic suggests that people who are not toxicologists may apply a “law of contagion” to toxicity. Just as brief exposure to a microscopic virus can result in lifelong disease, we assume that exposure to any amount of a harmful chemical will permanently contaminate our bodies. “Being contaminated,” Slovic observes, “clearly has an all-or-none quality to it—like being alive or pregnant.” Fear of contamination rests on the belief, widespread in our culture as in others, that something can impart its essence to us on contact. We are forever polluted, as we see it, by contact with a pollutant. And the pollutants we have come to fear most are the products of our own hands. Though toxicologists tend to disagree with this, many people regard natural chemicals as inherently less harmful than man-made chemicals. We seem to believe, against all evidence, that nature is entirely benevolent.