Many critics of nuclear power have very little understanding of radiation and its dangers, but that doesn’t mean that it is not well understood by experts. Scientists understand a great deal about radiation, and there is an enormous scientific lit­erature on radiation and its effects. Radiation is not something outside human experience—rather, it is something that was present as life evolved, and our cells developed repair enzymes to repair DNA damage caused by radiation. We are constantly exposed to radiation from the air (cosmic rays), from the earth (pri­mordial radioisotopes such as uranium, thorium, and radon) and from the food we eat (40K in bananas and other foods). Many people live in areas with high levels of natural radiation—like those of us who live in Colorado—but there is no cor­relation between these higher background levels of radiation and the risk of can­cer. And many people get as much or more exposure to radiation from medical procedures as they do from natural sources.

The risks of radiation have been better studied than probably any other toxic compound. It is, of course, true that radiation can cause cancer, but it is a sig­nificant risk only at high doses. The risks are well understood and can be strictly related to dose. Nuclear critics virtually never mention dose and they imply or state that radiation from a nuclear power plant or from nuclear waste is somehow especially evil. The truth is that there is no difference between an a, p, or у from natural sources and one that comes from a nuclear reactor. All that matters is the dose. We also know that the relative biological effects depend on the specific kind of radiation and the sensitivity of specific tissues. So we actually understand radiation and its effects very well, and we can make specific predictions about the probability that exposure to a particular dose of radiation will cause a cancer.

It is often said that plutonium is the most toxic compound on earth. In fact, it is not particularly toxic and is hardly absorbed by the body at all. Its danger is primarily if it is inhaled and remains trapped in the lungs. It is an a emitter and, like radon, can cause lung cancer if a sufficient dose is given. The people with the most exposure to plutonium were workers at Los Alamos who built bombs—the infamous UPPU club—and they had lower cancer rates than the general public. In fact, there is no known population of people who have gotten cancer from plu­tonium. It is time to put this myth to rest.