Holy Cow! Here we go again. The Nuclear Regulatory Commission (NRC) has commissioned a study by the National Academy of Sciences (NAS) of cancer rates as a function of proximity to nuclear power plants. The study will address the assertion by anti-nuclear groups that nuclear power plants cause leukemia. I insist on calling them anti-nuclear groups instead of “environmental” groups because I am executive director of an environmental group (Citizens for Nuclear Technology Awareness) and we are pro-nuclear.
I have a great deal of respect for the NRC and for the NAS and I am confident that no correlation exists between proximity to nuclear power plants and incidence of disease due to low-level ionizing radiation. The problem is that epidemiological studies cannot rule out factors that may be much more important than the subject of the study and the results often have a margin of error that renders most of the data statistically insignificant. When this happens, people interpret the data to suit their own purposes.
The premise is that low-level ionizing radiation emitted from nuclear power plants causes cancer. Now, consider that coal-fired power plants emit many times more radiation than do nuclear power plants, so why don’t we do that study? Just so you know where I’m coming from, that study wouldn’t be statistically significant either.
The average person receives background radiation doses of about 300 millirem(mr) per year, exclusive of medical procedures that on average add another 300 mr or about 600 mr per year per person. An mr is a measure of radiation. Background radiation dose varies by location in the U.S. and even more so in the rest of the world with some places in India and Iran that have background radiation levels of several thousand mr annually with no known health effects.
The American Nuclear Society estimates that living within 50 miles of a nuclear power plant adds about 0.01 mr to a person’s total annual background radiation dose - about the same as eating one banana. About 40 mr of our annual dose comes from our own bodies. Yes, we are radioactive – every living thing is radioactive and always has been. This means that if a normal person gains 10 percent of his or her body weight, he or she will increase their background radiation exposure by 4 mr, or 400 times the amount of exposure realized by living in proximity to a nuclear power plant. Now you may see what I mean when I say these studies cannot account for factors that are much more important than the subject of the study.
We can expect anti-nuclear groups to hang on to their dogma in the face of overwhelming evidence that their premise is nonsense, but it is disappointing to find the NRC and the NAS lending credence to their position by sponsoring this study with our money. Oh yes, the study will cost approximately $2 million.
Epidemiologists are still trying to sort out the effects of the huge amounts of radiation released in the Chernobyl accident, but have found little impact on human health. A similar conclusion may be drawn from a study of the atomic bomb survivors from Hiroshima and Nagasaki, Japan in 1945. More than 85,000 persons exposed to radiation doses from 30,000 mr to 600,000 mr were studied. A control group of unexposed Japanese would have been expected to experience an 8.4 percent chance of dying from a solid tumor cancer. The exposed group experienced an 8.8 percent rate. This was judged to be barely statistically significant since most epidemiology studies have a 3-5 percent margin of error. Most of the apparent increase in cancer incidence occurred in those who received very high doses of radiation while those receiving lower doses actually had lower rates than the control group.
A more statistically significant result was that the exposed group showed one leukemia case more per thousand people than the expected rate. These exposures were approximately 10 million times higher than what the NAS will be studying, so one can be forgiven if one is skeptical that any credible scientific conclusion will come from this study.
Clint Wolfe is the Executive Director for the Citizens for Nuclear Technology Awareness.