A feature article in the August 2012 issue of Scientific American trumpets a scary warning: “Deadly Rays from Clouds—Thunderstorms Give Out Powerful Blasts of X-Rays and Gamma Rays.”1
Headlines are written to grab the reader’s attention—whether or not the article’s content lives up to the hype. At the end of this particular article, the authors reveal that the real hazard is somewhat less frightening: “thunderstorms most often emit a relatively harmless, continuous glow of gamma rays. Preliminary calculations, however, show that if an airline flight happened to be struck directly by the energetic electrons and gamma rays [up to 100 million electron volts (MeV)] inside a storm, passengers and crew members could—without feeling anything—receive up to a lifetime’s natural radiation dose in a fraction of a second.”2
This raises the question of God’s providence. Humankind is bombarded by cosmic rays and radiation from a variety of natural sources in the Earth.3 Conventional wisdom—both among scientists and the lay public—suggests that all radiation is harmful.
Would a benevolent God subject the crowning glory of his creation—humankind—to bombardment by deadly rays, which provide no benefit to humanity and are harmful in even the smallest quantity? And if so, would not God design a compensatory biological system?
Indeed, in reviewing the data, we see a remarkable instance of divine design.
The concern that all radiation is harmful, even at the lowest levels, can be traced to a 1946 Nobel Prize lecture given by Hermann Muller. Although a recent review of Muller’s papers reveals that he was aware of contrary data at the time of his lecture,4 one must remember that in 1946 many scientists were reacting with horror and regret to the radiation effects of the atomic bombing of Japan the year before. Furthermore, in the absence of definitive data, the scientific community concluded that the safest approach is to assume all radiation is harmful. Later data, showing DNA strand breaks due to low-level radiation doses, seemed to support this “linear no-threshold” (LNT) hypothesis.
However, studies conducted over nearly 100 years5 indicate that radiation is beneficial in low doses—although its effects are lethal or carcinogenic at high doses.
Even so, radiation is necessary for life as we know it. In the 1950s, studies at Oak Ridge National Laboratory showed that animals were stated to have “done poorly” when radioactive potassium (K-40) was removed from their diets, yet they recovered when the extracted K-40 was returned; also, cells without K-40 “looked good but they didn’t function.”6 In other words, our bodies seem to be designed to work in an environment of low-level radiation.
In fact, “low-to-intermediate doses [of ionizing radiation] have been observed to enhance growth and survival, augment the immune response, and increase resistance to mutagenic and clastogenic effects of further irradiation in plants, bacteria, insects, and mammals.”7 A 1961 article in the Journal of the American Medical Association (JAMA) reviewed all known low-dose studies (defined as “to about 1 rad [10 mSv]3 per day”) and concluded: “The preponderance of data better supports the hypothesis that low chronic exposures result in an increased longevity than it supports the opposite hypothesis of decreased longevity.”8 (10 mSv/day is 1,000 times more than the natural background.) Furthermore, “Animal studies have revealed that LDR [low dose radiation] … inhibits carcinogenesis induced by high dose radiation.”9 Furthermore, “It has been extensively and consistently confirmed that supplemental radiation, above the natural background level, stimulates organisms, enhancing their growth and increasing their mean lifespans.”10 A study has shown that “cancer-prone” mice given low-level radiation were found to be less susceptible to “spontaneously initiated” cancer.11
Most home-sellers are required to test for radon—and sometimes undertake expensive corrections if it is detected. However, a University of Pittsburgh study compared radon exposure and lung cancer rates in 1,729 counties, covering 90 percent of the U.S. population, and found far fewer cases of lung cancer in counties with the highest amounts of radon (a correlation that could not be explained by smoking rates).12
The question is: why is low-level radiation beneficial? Research suggests the answer may be divine design.
Evidence has accumulated over many years that the body is equipped with a mechanism to repair radiation-induced DNA mutations. Multiple papers over the last twenty-plus years have shown a pattern of DNA-strand breaking and resealing due to low-level radiation.13 Radiation biologists have observed “the capacity of a cell to react to a low [radiation] dose by increasing its radio-resistance to a subsequent high dose challenge,”14 that “human lymphocytes exposed to low doses of ionizing radiation … become less susceptible to the induction of chromatid breaks by high doses of X-rays,”15 and even that “exposure to low levels of chronic radiation can trigger or induce increased repair of radiation-induced chromosome breaks.”16
A recent article in the Proceedings of the National Academy of Sciences reports the following:
Radiation-induced foci (RIF) in human cells … are characterized by the local recruitment of DNA damage sensing proteins.…We provide strong evidence for the existence of repair centers … [and] we show that multiple DNA double-strand breaks (DSBs) 1 to 2 μm apart can rapidly cluster into repair centers … We observe an absolute RIF yield that is surprisingly much smaller at higher doses … Our discovery of DSB clustering over such large distances casts considerable doubts on the general assumption that risk to ionizing radiation is proportional to dose.17
So what does all this mean to the average person? I wouldn’t advise uranium baths to get extra radiation—as people did in the 1950s. However, the main point is not to have an unreasonable fear of radiation, as implied by the headline of the Scientific American article, because the design of the cell automatically compensates for reasonable exposure levels.
What is a “reasonable” exposure level? A recent article in the Health Physics journal provides some guidelines: “The linear no-threshold (LNT) model [which suggests all radiation is harmful] ... is not supported by scientific data at doses less than about 100 mSv or at chronic dose rates up to at least 200 mSv/yr.”18 200 mSv/yr is of course almost 100 times natural background radiation.
Exposure from a full-body CT scan is about 10–12 mSv; a person would need to have more than ten CTs a year before becoming concerned. A mammogram is about 1–2 mSv—less than annual background—and exposure from dental X-Rays are too low to matter. The Scientific American article claims if an airplane is in just the wrong place at just the wrong time, people would “receive up to a lifetime’s natural radiation dose;” but in reality, the radiation would just barely reach the level for which they might be concerned.
Furthermore, cancer patients can receive as much as 80,000 mSv to localized areas with curative intent and no anticipation of long-term detrimental effects. My mother was cured of cancer due to a high dose to a small area with no side effects—as is typical with modern radiation oncology. And this happens because of another miracle of cell design: normal cells are able to repair radiation damage more rapidly than cancerous cells.
Dr. Hugh Henry, PhD
Dr. Hugh Henry received his PhD in Physics from the University of Virginia in 1971, retired after 26 years at Varian Medical Systems, and currently serves as Lecturer in physics at Northern Kentucky University in Highland Heights, KY.