Radiation : The No-Safe-Level Myth

Assuming the worst can be hazardous to your health

“Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less.” (Marie Curie)

Beginning with the accident at Three Mile Island in 1979, a widespread belief has proliferated that all levels of ionizing radiation are dangerous. Since 1980, radiation hormesis studies have shown there is actually a threshold of danger with high level exposures, but below that threshold low dose radiation is essentially safe and quite possibly beneficial to life. Yet, this relatively new, seemingly contradictory understanding of radiation’s health effects has gone essentially unknown to the general public. In order to grasp the reasons why, we must again return to the bombing of Hiroshima and Nagasaki.

The world’s first atomic bomb explosion occurred on July 16, 1945, at the Alamogordo facility in New Mexico, and was called Trinity. Trinity proved that a high concentration of U-235 and/or Pu-239 could be used to make a titanic explosive. Not quite a month later, an atomic bomb was dropped over Hiroshima, followed a few days later by another dropped on the outskirts of Nagasaki. Estimates of the number of Japanese killed by the blasts vary, but the most common numbers are 135,000 at Hiroshima and 73,000 at Nagasaki. These toals are those killed by the detonations itself and those who died days and weeks later of blast-induced physical traumas and burns. This enormous number of deaths equates favorably with any explosion of more than 35 thousand tons of TNT (35 kilotons) in urban settings of these two sizes. In addition, another 140,000 deaths occurred in the 5 years after the war which were largely attributed to the biological effects of enormous doses of Neutron and Gamma radiation from the blasts themselves and the ingested radioactive fallout the blasts produced.

Rough estimates of the radiation doses received by those who died of radiation exposure were made, and analyzed. It was discovered that doses in excess of  1 Sievert(100 Rem) inflicted over relatively short periods of time caused about a tenth of a percent of those exposed to die of a variety of radiation-related reasons, including cancer. Those who received doses in excess of ~6 Sieverts had a 99% mortality rate. At 10 Sieverts, everyone died. We must stress that the above exposures were experienced over a very short time period; a few seconds due to the burst of gamma and neutron rediation produced by the explosions, and a few minutes due to massive ingestion of the radioactive activation products in the air (inhalation and/or swallowing).

Using these morbid statistics to graph the effects on grids which would be used for future risk estimates, a direct relationship was found between dose and death in the region between 1 Sievert and 10 Sievert of acute (short duration) exposure. Beginning at 6 Sieverts, the risk of dying decreased in a diminishing fashion with respect to decreasing dose. Using a logarithmic scale to keep the data analysis readible on one page, a straight line could be drawn from the 6 Sievert dose death rate of 99% and down through the 1.5 Sievert death rate of <1%. Though no data was used to support it, the line could be mathematically continued down to zero dose and still show potential risk of morbidity, albeit nearly zero risk at very low exposure levels. On this arbitrary line, the only zero-risk point was at zero dose.


The graph made it seem that even the tiniest imaginable doses of radiation posed a possibility of producing cancer. It also fit a graph created by Nobel Laureate Herman Muller in his 1927 experiment with fruit flies exposed to varying levels of X-ray radiation. This also fit well with the highly conservative medical cancer-one-cell theory which held that once one cell in your body became cancerous, there was a risk of dying of that cancer. With both cancer induction and radiation exposure, no credit was given for our body’s natural repair mechanisms. Thus, it was assumed there is no safe level of cancer, so by association there is no safe level of radiation. The “Linear No-Threshold” (LNT) or no-safe-level assumption of ionizing radiation had begun.

It should be noted that as the time frame over which an exposure occurs increases, the doses needed to produce these negative biological effects also increases. If the length of time for exposure takes more than an hour, the doses needed for adverse biologically/medically observable effects nearly doubles. That is, the effects of a two sievert exposure occurring over a one hour period would be about the same as a one sievert exposure occuring in less than a minute. However, this fact is never considered when using the LNT model to set radiation exposure limits or making estimates of potential health effects to a population over a period of months or years.

In 1958, The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), using Japanese bomb data, Herman Muller’s fruit fly model published in 1927, data taken from American and Russian military bomb-test over-exposures, and other acute radiation over-exposure data – all of which were doses absorbed in the space of seconds to minutes –  published a two part summation on the biological effects of ionizing radiation,

  • Effects of low doses of ionizing radiation can be estimated by the linear extrapolation of effects observed from high doses.
  • There is no safe dose (of radiation) because even very low doses of ionizing radiation can theoretically produce some negative biological effect.

In 1959, The International Commission on Radiation Protection (ICRP), perhaps the most prestigious independent organization of its kind in the world, adopted the no-safe-level assumption to be used in any and all risk analyses associated with radiation exposure. In addition, it was (and still is) assumed that exposures experienced over lengthy time-frames will be essentially the same as exposures that occur over short periods of time, although there is no actual data to support this assumption. In other words, cellular and genetic damage caused by radiation is presumed to accumulate and will never be repaired by our natural repair mechanisms! Though clearly a false conjecture, it is part-and-parcel to the no-safe-level rationale.

50 years ago, there was little evidence from human populations other than extrapolations (statistical predictions) to support the no-safe-level assumption in the low dose range. Since it would surely over-estimate rather than underestimate risk below 1 Sievert exposures, the no-safe-level hypothesis was used universally for risk analysis and eventually became a regulatory paradigm. Little thought was given to the possible adverse psychological effect the no-safe-level assumption could have on the public. It should be noted that all prestigious scientific bodies in the world stress that the LNT assumption should only be used for setting regulatory standards, but never used to estimate potential levels of mortality.

Then came the Three Mile Island (TMI) accident in 1979, and the no-safe-level assumption became widely known for the first time. Fears of a cancer epidemic coursed through the effected population. Although even the most extreme estimates of radiation doses to the exposed TMI public were many, many of times lower than any dose that had ever been shown to actually cause cancer, widely-published additional cancer estimates in the exposed population ranged from a few tens to thousands. However, follow-up studies of cancer mortality over the 30 years after the accident have shown nothing statistically significant as a result of the accident. Remarkably, the medical records of the exposed population from Chernobyl, some 25 years after the accident, also show no increases in cancer incidence or mortality. The no-safe-level assumption cannot account for this. If no-safe-level is correct, there should have been at least a small increase in cancer rates over the decades since TMI and Chernobyl…especially Chernobyl.

Astonishingly, something significant happened barely a year after TMI and went largely unreported.  A research paper was published out of the Universities of Miami and Missouri entitled Hormesis with Ionizing Radiation by Missouri Micro-Biology Professor T.D. Luckey. This study not only challenged the no-safe-level idea, it literally disproved the assuption at chronic (constant) dose levels below ~1500 millisieverts, and acute (short term) exposures below ~700 mSv. In fact, the study strongly suggested that low level “background” radiation, and all exposures near background, may be the operational catalyst for the immune system in mammals. No radiation exposure and the immune system won’t work. Luckey’s research showed a mortality rate of 100% at zero radiation dose due to massive immune system dysfunction. Thus, the study seemed to demonstrate that we cannot live without low level radiation. If there is no-safe-level to ionizing radiation because huge levels of exposure surely cause cancer, how can it be that low levels of radiation might be completely safe and possibly essential to life?

Hormesis and Radiation

Hormesis is a concept which can be traced back to the ancient Greeks, who believed that too much of anything can be deadly. Conversely, substances that are harmful in large amounts can be beneficial to life in small amounts. To put it another way, the 16th century natural philosopher Paracelsus said, “The dose makes the poison.” Surely, high doses of many substances found on Earth can be life-threatening, but low doses of the same substances often have the opposite effect. Take vitamins, for example. Typical vitamins include small concentrations of substances such as Iron, Magnesium, and Zinc, which are necessary to good health if not essential to life. In large, naturally-occuring concentrations, these minerals are deadly toxins. It seems Hormesis occurs with radiation, as well. Dr. Luckey discovered that doses below 500 mSv produced no harmful effects at all, and there was a lethal threshold of about 1000 mSv (less than 1%).

The below graphs use a “control” line where doses above it are considered potentially toxic, and below it are considered beneficial.

Rad dose curves

The typical American receives about 3.3 millisieverts of radiation per year from naturally radioactive atmospheric gasses, food, water, cosmic rays, the soil beneath our feet, building materials (adobe brick is a big one), and other people near us. We also get, on the average, another 3 mSv from man-made sources like medical and dental X-rays. We each get less than 0.01 mSv/yr from the sum total of all nuclear power plant operations in America. The American average dose due to all sources of radiation is about 3.6 mSv/yr, of which less than 0.3 percent comes from nuclear power plants. What’s more, the total dose of radiation from the TMI accident to any member of the exposed public living next door to the plant and downwind was no more than 0.4 mSv. This means the TMI population-most-at-risk got about 4 mSv for the year of the TMI accident, rather than the 3.6 mSv they would have received anyway. This is well below the 50 mSv exposure that holds a vanishingly slim chance of actually being harmful, and the 1 Sievert threshold that holds a very tiny chance of actually producing cancer mortality.

Why has TMI not become a hotbed of cancers? Because, in the words of Dr. Robert Boyar of Argonne National Laboratory, “There are no data that support a linear inference of harm from nuclear radiation down to zero effect at zero dose. The data indicate that people would live longer and healthier lives if they received a little more radiation, not less.” The complete lack of negative health effects from TMI and the lack of negative long-term health effects from Chernobyl, supports Boyar’s statement. The health effect data on exposures to the public from TMI and Chernobyl perfectly fit the concept of Hormesis, but do not fit the no-safe-level assumtion.

In the thirty years since hormesis with ionizing radiation was first discovered, numerous laboratories all over the world, from Japan to Switzerland, have come to essentially the same conclusion. In enormous doses, radiation is a deadly toxin that can, and does cause high cancer mortality. However, in low doses, such as those we experience continually as a result of living in a naturally radioactive universe, the effects provide a positive stimulation to life, and may well make life-itself possible for our species. The no-safe-level idea for ionizing radiation can now be understood to be little more than a myth with respect to low level exposures!

Why, then, does the no-safe-level, zero-threshold “theory” continue to be widely accepted? Dr. Boyer makes a bold statement as to the reason, “Why, in the face of the evidence, does the zero-threshold concept remain so politically correct? More to the point, consider who benefits. Are there people who make their living exploiting the zero-threshold theory? You bet! Think of the government employees at the federal, state, and local levels who use zero threshold to concoct regulations for nuclear power plants, nuclear waste disposal, radon in homes, etc. Think of the government-sponsored researchers on disposal of nuclear waste, who search for ever more esoteric ways to protect people 50,000 years hence from a conceivable, trivial addition to the natural radiation background. One might call it ‘bureaucratic free enterprise.’”

Strong words, indeed. Add to this those in the public, political and environmental activist arenas whose reputations depend on their exaggerated prophecies of nuclear doom, and we can see that the business of keeping the no-safe-level myth alive is considerable. Without the public becoming aware of the truth and demanding the use of scientific correctness, this unethical practice will continue and fear of the low-level-radiation “bogey man” will endure. Once the public becomes aware of the safety concerning low level radiation exposures and makes their collective voice heard, the no-safe-level myth can be discarded and become little more than an historical point of interest similar to the false belief that the Earth is the center of the universe.

Radiation is Invisible and Insidious…Right?

One of the most enduring and frightening, albeit misleading concepts concerning ionizing radiation is twofold; radiation is invisible and insideous, making it inordinately dangerous. First, radiation is invisible to the naked eye, allowing it to hide before it strikes with mortal finality. Second, radiation is insidious, lurking in sinister purpose over long periods of time before it manifests and kills us. Radiation is thus presented as the most horrific terrorist phenomena imaginable. The combined notions are misleading and used in a fashion that is unethical and morally corrupt. Each notion needs to be addressed individually in order to demonstrate their unconscionable damaging effects on the public mind.

Radiation is invisible. No doubt about it. So are all of the elements in the air we breath. Is Oxygen or Nitrogen especially dangerous because they are invisible? Of course not. Can the air contain other invisible substances? Of course it can. Does their being invisible make them automatically deadly? Absolutely not. But, radiation is presented to the public as if it’s invisible-to-the-naked-eye nature makes it singularly and uniquely dangerous because it is invisible! Of all the hypothetically dangerous invisible substances that might possibly surround us, radiation is probably the safest of the lot. Low levels of invisible radiation are not in the least harmful. We are exposed to radiation every moment of every day we exist. Further, our species has evolved in a naturally radioactive world, which says a lot about it’s safety level. Plus, it is relatively easy to detect. Radiation detectors are widespread in hospitals, research facilities, colleges, emergency centers…virtually everywhere. But, most people don’t have one in their homes. However, Geiger Counters are relatively inexpensive, can be bought by anyone, and are quite easy to operate. Clearly, the invisible nature of radiation in no way makes it uniquely dangerous. In fact, low, non-lethal levels of exposure are safe and life-enhancing.

The insidious notion is even more misleading and several magnitudes more terrifying than the invisibility idea. First, most people have little or no idea what the frightening term means. Actually, it has two overlapping meanings. One meaning is something treacherous, awaiting the best possible moment to entrap us and do us harm. Second, it is also something that has a subtle and cumulative effect on us, which builds up it’s lethal potential over time. The dose you receive today might not make you sick tomorrow, but if that dose continues to be received every day, over extended periods of time, it’s assumed to be just as dangerous as the huge, flash doses that killed thousands at Hiroshima. In the first place, how can the most ubiquitous and constant phenomena in the universe (radiation) which has engulfed our species for the millions of years we have evolved, be singularly treacherous, hiding in silence and awaiting the optimum moment when it can suddenly inflict sinister biological havoc? It defies rational logic. Secondly, the concept that radiation exposure has a cumulative effect, building up in it’s terrible inevitability over time, has no evidential foundation, whatsoever! Yes, the notion of risk accumulation (build-up) with respect to radiation exposure has been with us since the dark days of gathering Hiroshima survivor data and the formulation of the no-safe-level hypothesis, but there is absolutely no human or laboratory animal data to support it. None! It was assumed as an ultra-conservative corollary to the no-safe-level hypothesis, just to err on the side of safety. Assumed, but never proven! This arbitrary assumption officially exists to this day, is one of the sovereign foundations of unnecessarily restrictive government limits on human exposures, and does little more than needlessly prolong the accumulation of avoidable psychological damage to the public from the Hiroshima Syndrome.

It should be noted that current research on single living cell DNA and multi-cellular laboratory animals demonstrates the biological mechanisms at work. Low level radiation exposure actually improves an individual cell’s ability to repair damage to its DNA, much the same as physical exercise improves muscle tone. It also has a cumulative effect of improved DNA repair for the remaining lifetime of the cell. In other words, radiation exposure has a positive cumulative effect in non-lethel doses, but there is no negative cumulative effect! In addition, irradiated cells tend to live longer than non-irradiated cells. These phenomena have also been found to be the case with multi-cellular laboratory animals. By increasing radiation exposure above normal background levels, living creatures experience better cellular repair functions and have longer lifetimes. There are accumulated health effects due to increased exposure levels, but all of the effects are positive, health enhancing, and life-extending.

Why can the two united concepts of “invisible and insidious” be judged as morally corrupt? Because they depend on the naivety of an ill-informed public in order to achieve a reprehensible effect. It’s literary and philosophical terrorism, to the extreme. Yes, radiation is invisible, as are nearly all substances in our gaseous atmosphere. No, radiation is not insidious. Radiation is not a singularly dangerous, uniquely horrific, invisible and insidious phenomena. These two false, commonly-held historical notions attached to radiation are, however, decidedly invisible and insidious psychologically. The psychological damage of the no-safe-level myth is enormous, and the psychic impairment is decidedly cumulative. Further, the historically persuasive notion of radiation being inordinately dangerous because it is allegedly invisible and insidious, continually presented to this day, reinforces its three decades of moral corruption and continues to intensify the negative psychic effects of the Hiroshima Syndrome as it accumulates in the public mind.

Effects of the No-Safe-Level Assumption

After the accident at TMI, the groundless no-safe-level theory of low radiation exposures was added to the public’s already-existent confusions between reactors and bombs, and between fallout and radiation itself. Subsequently, the no-safe-level theory amplified the Hiroshima Syndrome to a level of full-blown public phobia relative to all things nuclear and expanded its damaging tendrils into anything associated with radiation. If and when the no-safe-level theory of radiation exposure is exorcised from the public’s political and informational arenas, only then can the negative psychological impacts of the Hiroshima Syndrome be effectively addressed and eventually healed. As long as the no-safe-level theory is maintained, the Hiroshima Syndrome will continue to damage the psyche of all humanity, restrict the therapeutic and healing effects of non-lethal doses of radiation, limit the growth of clean and green nuclear energy, and un-necessarily prolong the practice of burning fossil fuels in order to produce large round-the-clock volumes of electricity.

From Around The World…

T. D. Luckey (USA) : “Ionizing Radiation is a benign environmental agent at background levels. We live with a subclinical deficiency of ionizing radiation. Low levels of ionizing radiation significantly decrease premature cancer death. Health benefits should replace risk and death as the guide for safe exposures to ionizing radiation. Safe supplementation with ionizing radiation would provide a new plateau of health. Our energy crisis is based upon spin and deceit by our official advisory committees using the false dogma that all radiation is harmful. We need more ionizing radiation for the health of people and the wealth ($billions wasted each year) of our nation. Nuclear power is needed to provide balance in our energy policy and independence from foreign energy sources.”

Calabrese and Baldwin (USA) : “The Hormetic Dose Response represents a paradigm shift in the concept of the dose response throughout biological sciences. It is widespread and outperforms other dose-response models.”

Sadao Hattori (Japan) : “In 1982, Professor Thomas Don Luckey of Missouri University asserted ‘radiation hormesis’ in the journal Health Physics. Following his assertion, the CRIEPI initiated a research programme on radiation hormesis to confirm ‘is it true or not’. Twelve years of research with 8–14 universities in Japan produced fruitful results on radiation hormesis. Hormone response tests on rabbits, enzyme response tests on rats and mice, p53 gene responses from mice and rats and helper-T responses from human patients gave us impressive information to consider the therapeutic application of radiation hormesis.”

Robert E. Boyer (USA) : “There are no data that support a linear inference of harm from nuclear radiation down to zero effect at zero dose. The data indicate that people would live longer and healthier lives if they received a little more radiation, not less.”

Ron Mitchel and Doug Boreham (Canada) : “When the data do not support the hypothesis being tested, that hypothesis must be rejected and replaced with a new testable hypothesis. Since, at low doses and dose rates, there are no data in the literature that support the LNT hypothesis for cancer risk, and considerable evidence contradicting it… then this hypothesis must therefore be rejected. It is time for a new risk based approach to radiation protection, firmly linked to the actual biological responses.”

Cuttler (Canada) and Pollycove (USA) : “The notions that no amount of radiation is small enough to be harmless and that a nuclear accident could kill hundreds of thousands are challenged in light of experience…regulatory authorities must examine the scientific evidence and communicate the real health effects of nuclear radiation. Negative images and implications of health risks derived by unscientific extrapolations of harmful effects of high doses must be dispelled.”

Gunnar Walinder (Swedish radiobiologist) : “The LNT hypothesis is a primitive, unscientific idea that cannot be justified by current scientific understanding.  As practiced by the modern radiation protection community, the LNT hypothesis is one of the greatest scientific scandals of our time.”



  1. Radiation occurs everywhere as a natural part of the world…everyone and everything is naturally radioactive.
  2. The no-safe-level theory of radiation only applies to enormous exposures (above 100 REM) absorbed over a short period of time.
  3. Low levels of radiation exposure over long periods of time, up to 500 times typical natural background levels, are not harmful.
  4. Low level radiation is beneficial to human health, improves damage recovery, and is essential to the functioning of the immune system.
  5. Way too much or way too little of a good thing can be deadly.



  1. The First Atomic Test; Trinity Atomic Web Site; U. S. Department of Energy; 2005
  2. Luckey, T.D.;  Hormesis with Ionizing Radiation; CRC Press, Boca Raton, 1980.
  3. Luckey, T.D.; Radiation Hormesis Overview; RSO Magazine; Volume 8, Number 4; 2003
  4. Boyar, Robert E.; Radiation and Common Sense; Center for Reactor Information; U.S. Department of Energy, Washington, D.C.; 1997
  5. Radiation Hormesis Explained; Low Level Ionizing Radiation Therapy Center; 2009
  6. Talbot, Youk, McHugh-Pemu, and Zborowski;  Long-Term Follow-Up of the Residents of the Three Mile Island Accident Area: 1979-1998; Environmental Health Perspectives; 2002
  7. No Apparent Increase In Cancer Deaths Among Three Mile Island Residents, Report University Of Pittsburgh Researchers; Science Daily; June 1, 2000
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    http://www.angelfire.com/mo/radioadaptive/inthorm.html; (No date available)
  9. Calabrese, E.J. & Baldwin, L.A.; Hormesis Demands a Reappraisal of the Way Risks are Assessed; Dept. of Environmental Health Sciences, University of Massachusetts; Nature; Vol.421; www.nature.com; February 13, 2003 (link – http://www.ecolo.org/documents/documents_in_english/CalabreseNat-Hormesis-03.pdf)
  10. Hattori, Sadao; Radiation hormesis research findings and therapeutic applications; CRIEPI; Chiyodaku, Tokyo, Japan; International Journal of Low Radiation 2005 – Vol. 1, No. 4, ppg. 369-75
  11. Muckerheide, James; It’s Time to Tell the Truth About the Health Benefits of Low Dose Radiation; Co-Director, Center for Nuclear Technology and Society at Worcester Polytechnic Institute in Massachusetts; 21st Century Science Associates; 2005 www.21stcenturysciencetech.com
  12. Mitchel, R.E.J., and Boreham, D.R. ; Radiation Protection in the World of Modern Radiobiology : Time for a New Approach: Chalk River Laboratories; Radiation Science and Health; April 17, 2006 http://www.physics.ox.ac.uk/nuclearsafety/Ron%20Mitchel%20and%20Doug%20Boreham,%20AECL,%20IRPA-10,%20May%202000.htm
  13. Werner Olipitz, Dominika Wiktor-Brown, Joe Shuga, Bo Pang, Jose McFaline, Pallavi Lonkar, Aline Thomas, James T. Mutamba, Joel S. Greenberger, Leona D. Samson, Peter C. Dedon, Jacqueline C. Yanch, Bevin P. Engelward. “Integrated Molecular Analysis Indicates Undetectable DNA Damage in Mice after Continuous      Irradiation at ~400-fold Natural Background Radiation.”; Environmental Health Perspectives, 2012; DOI: http://ehp03.niehs.nih.gov/article/info%3Adoi%2F10.1289%2Fehp.1104294
  14. Hattori, Sadao; Using Low-dose Radiation for Cancer Suppression and Vitalization; 21st Century Science and Technology; Summer 1997, Vol. 10,
  15. Neumaier, Swenson, et. al.; Evidence for formation of DNA repair centers and dose-response nonlinearity in human cells; Lawrence Berkeley Laboratories; in “Proceedings of the National Academy of Sciences”, #1117849108, December 19, 2012. http://www.pnas.org/content/early/2011/12/16/1117849108.full.pdf+html
  16. Henriksen, Thormod; Radiation and Health; University of Oslo; 2009  http://www.mn.uio.no/fysikk/tjenester/kunnskap/straling/radiation-health-2012.pdf
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