An increasingly used anti-nuclear argument claims “it is impossible to prove the non-existence of something,” therefore we can’t be sure that low-dose radiation is harmless. Some day we may discover victims of low-dose radiation, just as we one day discovered the existence of black swans – lots of them (in Australia). We may find circumstances under which irradiated people – perhaps lots of them – are injured by radiation. So the prudent course, the argument goes, is to assume for regulatory purposes, that radiation is harmful all the way down to zero dose.
But this argument is phony. There is no “non-existence of evidence.” The evidence that low-dose radiation is harmless or beneficial is all around us. James Muckerheide wrote a report with the self-explanatory title: “There Has Never Been a Time That the Beneficial Effects of Low-Dose Radiation Were Not Known.” He documents that over a century ago, during the first decades after the discovery of x-rays, radium, and radioactivity, the beneficial effects were explicitly understood and reported. The phenomenon of a substance or a process being harmful at high levels and beneficial at low levels is nearly universal and is called “hormesis.” We see it with sunshine, vaccination, exercise, and other forms of challenging our bodies. So we were taught “Moderation in all things” and we avoid extremes.
In 1980 and in 1991, T.D, Luckey published two landmark volumes: “Hormesis with Ionizing Radiation,” and “Radiation Hormesis," CRC Press. With over a thousand references each, these books struck a chord with several Japanese scientists, and they began doing experiments with mice, and then clinical work with humans, demonstrating the beneficial effects of full-body and half-body irradiation for curing cancer.
Decrying the fear-mongers, Rosalyn Yalow, Nobel Laureate in Medicine, asserted:
No reproducible evidence exists of harmful effects from increases in background radiation three to ten times the usual levels. There is no increase in leukemia or other cancers among American participants in nuclear testing, no increase in leukemia or thyroid cancer among medical patients receiving I-131 for diagnosis or treatment of hyperthyroidism, and no increase in lung cancer among non-smokers exposed to increased radon in the home. The association of radiation with the atomic bomb and with excessive regulatory and health physics ALARA practices has created a climate of fear about the dangers of radiation at any level. However there is no evidence that radiation exposures at the levels equivalent to medical usage are harmful. The unjustified excessive concern with radiation at any level, however, precludes beneficial uses of radiation and radioactivity in medicine, science and industry. (Mayo Clinic Proc 69:436-440, 1994)
Hugh F. Henry at Oak Ridge summarized the low dose data in the Journal of the American Medical Association: (JAMA176, 27 May 1961)
A significant and growing amount of experimental information indicates that the overall effects of chronic exposure (at low levels) are not harmful…The preponderance of data better supports the hypothesis that low chronic exposures result in an increased longevity… Increased vitality at low exposures to materials that are markedly toxic at high exposures is a well-recognized phenomenon.
The legendary Lauriston S. Taylor, chair of the first radiation protection societies, stated:
“Today, we know about all we need to know to adequately protect ourselves from ionizing radiation... No one has been identifiably injured by radiation while working within the first numerical standards set first by the NCRP and then the ICRP in 1934 [about 35-fold higher radiation level than the present recommendations]. Let us stop arguing about the people who are being injured by exposures to radiation at the levels far below those where any effects can be found. The fact is, the effects are not found despite over  years of trying to find them. The theories about people being injured have still not led to the demonstration of injury and, if considered as facts by some, must only be looked upon as figments of the imagination.” Taylor, L.S. “Some Non-Scientific Influences on Radiation Protection Standards and Practice,” Health Physics, 39 851-874 (1980)
The Strange Story of Radon
In the environmental movement of the early 1970s, the Environmental Protection Agency was formed to stop technological Man from bulldozing the Garden of Eden. As the 1980s dawned, some scientists began to point out that in its zeal to eliminate all traces of radioactivity, EPA was now requiring nuclear power plants, nuclear medical facilities and industries using radiation, to monitor, control, and reduce radiation levels below the natural background radiation people were exposed to in their own homes from radon, a natural decay product of uranium. When forced to face this inconsistency, EPA performed a remarkable turnabout: Instead of admitting that its radiation protection standards were unrealistic, EPA announced it would regulate Nature. The environment, so poignantly portrayed as the innocent victim, was now to be seen as a merciless, silent killer.
Thousands of radon detectors were issued to school-children, who were told to measure the threat and to pressure their parents to do something about it. On February 19,1998, the National Research Council announced in report BEIR-VI that radon in homes causes 15,400 to 21,800 deaths each year in America, despite the fact that no evidence has ever directly demonstrated that radon in homes is harmful. The report noted that about 90% of the deaths attributed to radon occurred in smokers, and “most of the radon-related deaths among smokers would not have occurred if the victims had not smoked.” One reporter noted, “Only an EPA analyst would assume smokers begin smoking at birth.”
In the mid 1980s EPA began issuing pamphlets warning against the “colorless, odorless killer,” and running TV ads showing a typical American family sitting happily in their living-room while a dire warning is intoned against funereal background music. The skit ends as the parents, then the children, and finally the dog, turn to skeletons. The predicted annual death rate from radon was said to equal the death rate from automobile accidents.
There is actually a great deal of good data on radium and radon in homes. The most extensive and the most thoroughly analyzed is a series of measurements and calculations by the late Dr. Bernard L. Cohen, Professor Emeritus of Physics, University of Pittsburgh. Prof. Cohen supervised the measurement of radon levels in about 350,000 American homes and compared the radon levels, county by county, with the lung cancer mortality in each county (since lung cancer is the only potential health effect that radon might cause). Cohen surveyed nearly 2000 counties housing more than 90% of the U.S. population and therefore has excellent statistical precision. He found exactly the opposite of what he and the EPA expected. He found that the counties with the highest radon levels had the lowest lung cancer mortality and those with the lowest radon had the highest lung cancer. He then turned off his radon-removal system.
The first figure below shows EPA’s basis for its conclusions. The tall vertical lines show the uncertainty of each of the data points. The second graph shows Cohen’s data, with much less uncertainty because of the large amount of data he amassed. EPA's data is miners; Cohen's is people in their homes. Which data do you find most convincing?