Jerry M. Cuttler

Nuclear Energy and Health And the Benefits of Low-Dose Radiation Hormesis

Energy needs worldwide are expected to increase for the foreseeable future, but fuel supplies are limited. Nuclear reactors could supply much of the energy demand in a safe, sustainable manner were it not for fear of potential releases of radioactivity. Such releases would likely deliver a low dose or dose rate of radiation, within the range of naturally occurring radiation, to which life is already accustomed. The key areas of concern are discussed. Studies of actual health effects, especially thyroid cancers, following exposures are assessed. Radiation hormesis is explained, pointing out that beneficial effects are expected following a low dose or dose rate because protective responses against stresses are stimulated. 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: more than a century with radiation and six decades with reactors. If nuclear energy is to play a significant role in meeting future needs, 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.

COMMENTARY ON USING LNT FOR RADIATION PROTECTION AND RISK ASSESSMENT

An article by Jerome Puskin attempts to justify the continued use of the linear no-threshold (LNT) assumption in radiation protection and risk assessment. In view of the substantial and increasing amount of data that contradicts this assumption; it is difficult to understand the reason for endorsing this unscientific behavior, which severely constrains nuclear energy projects and the use of CT scans in medicine. Many Japanese studies over the past 25 years have shown that low doses and low dose rates of radiation improve health in living organisms including humans. Recent studies on fruit flies have demonstrated that the original basis for the LNT notion is invalid. The Puskin article omits any mention of important reports from UNSCEAR, the NCRP and the French Academies of Science and Medicine, while citing an assessment of the Canadian breast cancer study that manipulated the data to obscure evidence of reduced breast cancer mortality following a low total dose. This commentary provides dose limits that are based on real human data, for both single and chronic radiation exposures.

Commentary on fukushima and beneficial effects of low radiation.

Approximately 160,000 people evacuated the area around the Fukushima Dai-ichi NPP shortly after it was damage by the earthquake and tsunami. The evacuation order applied to 70,000 of them, while the other 90,000 left voluntarily and returned soon afterward. After more than two years, most of the 70,000 are still not allowed to return to their homes. The 1100 disaster-related deaths caused by the evacuation order show that this precautionary action, taken to minimize cancer risks, was not “conservative.” In this paper, recent studies are reviewed on the consequences of the radioactive releases and on the benefits of many medical treatments with low doses of radiation that were carried out until the 1950s, before the radiation scare was created. Recent research has shed light on the high rate of spontaneous double-strand breaks in DNA and the adaptive protections in cells, tissues and humans that are up-regulated by low radiation. These defences prevent, repair, remove and replace damage, from all causes including external agents. Cancer mortality is reduced. The ICRPs concept of radiation risk is wrong. It should revert to its 1934 concept, which was a tolerance dose of 0.2 roentgen (r) per day based on more than 35 years of medical experience.

Remedy for radiation fear - discard the politicized science.

The great tragedy of science—the slaying of a beautiful hypothesis by an ugly fact. —Huxley TH. English biologist (1825–1895) Seeking a remedy for the radiation fear in Japan, the author re-examined an article on radiation hormesis. It describes the background for this fear and evidence in the first UNSCEAR report of a reduction in leukemia of the Hiroshima survivors in the low dose zone. The data are plotted and dose-response models are drawn. While UNSCEAR suggested the extra leukemia incidence is proportional to radiation dose, the data are consistent with a hormetic J-shape and a threshold at about 100 rem (1 Sv). UNSCEAR data on lifespan reduction of mammals exposed continuously to gamma rays indicate a 2 gray/year threshold. This contradicts the conceptual basis for radiation protection and risk determination established in 1956–58. In this paper, beneficial effects and thresholds for harmful effects are discussed, and the biological mechanism is explained. The key point: the rate of DNA damage (double-strand breaks) caused by background radiation is 1000 times less than the endogenous (spontaneous) rate. It is the effect of radiation on an organisms very powerful adaptive protection systems that determines the dose-response characteristic. Low radiation up-regulates the protection systems, while high radiation impairs these systems. The remedy for radiation fear is to expose and discard the politicized science.

Commentary on Inhaled (239)PUO2 in Dogs - A Prophylaxis Against Lung Cancer?

Several studies on the effect of inhaled plutonium-dioxide particulates and the incidence of lung tumors in dogs reveal beneficial effects when the cumulative alpha-radiation dose is low. There is a threshold at an exposure level of about 100 cGy for excess tumor incidence and reduced lifespan. The observations conform to the expectations of the radiation hormesis dose-response model and contradict the predictions of the LNT hypothesis. These studies suggest investigating the possibility of employing low-dose alpha-radiation, such as from 239PuO2 inhalation, as a prophylaxis against lung cancer.

Treatment of Alzheimer Disease With CT Scans A Case Report

Alzheimer disease (AD) primarily affects older adults. This neurodegenerative disorder is the most common cause of dementia and is a leading source of their morbidity and mortality. Patient care costs in the United States are about 200 billion dollars and will more than double by 2040. This case report describes the remarkable improvement in a patient with advanced AD in hospice who received 5 computed tomography scans of the brain, about 40 mGy each, over a period of 3 months. The mechanism appears to be radiation-induced upregulation of the patient’s adaptive protection systems against AD, which partially restored cognition, memory, speech, movement, and appetite.

Evidence That Lifelong Low Dose Rates of Ionizing Radiation Increase Lifespan in Long- and Short-Lived Dogs

After the 1956 radiation scare to stop weapons testing, studies focused on cancer induction by low-level radiation. Concern has shifted to protecting “radiation-sensitive individuals.” Since longevity is a measure of health impact, this analysis reexamined data to compare the effect of dose rate on the lifespans of short-lived (5% and 10% mortality) dogs and on the lifespans of dogs at 50% mortality. The data came from 2 large-scale studies. One exposed 10 groups to different γ dose rates; the other exposed 8 groups to different lung burdens of plutonium. Reexamination indicated that normalized lifespans increased more for short-lived dogs than for average dogs, when radiation was moderately above background. This was apparent by interpolating between the lifespans of nonirradiated dogs and exposed dogs. The optimum lifespan increase appeared at 50 mGy/y. The threshold for harm (decreased lifespan) was 700 mGy/y for 50% mortality dogs and 1100 mGy/y for short-lived dogs. For inhaled α-emitting particulates, longevity was remarkably increased for short-lived dogs below the threshold for harm. Short-lived dogs seem more radiosensitive than average dogs and they benefit more from low radiation. If dogs model humans, this evidence would support a change to radiation protection policy. Maintaining exposures “as low as reasonably achievable” (ALARA) appears questionable.

The high price of public fear of low-dose radiation

1 American Nuclear Society, Peshastin, WA, USA 2 DOE Low Dose Radiation Research Program, Washington, DC, USA 3 Canadian Nuclear Society, Toronto, Canada 4 Nuclear Medicine, Heinrich-Heine-University, Dusseldorf, Germany 5 United Nations Scientific Committee on the Effects of Atomic Radiation, Buenos Aires, Argentina 6 Pacific Northwest National Laboratory, Richland, WA, USA 7 BECS Department, Brookhaven National Laboratory, Upton, NY, USA

The assumption of radon-induced cancer risk

We read with interest the article by Axelsson et al. [1] about the potential risk of lung cancer due to inhalation of radioactive radon gas. Indeed, this has been the subject of many scientific papers around the world for years without clarification of whether there is risk or there is no risk when the radon concentration is low. The paper by Axelsson et al. [1] states that ‘‘residential exposure to radon is considered to be the second cause of lung cancer after smoking.’’ The authors cite the publications of many well-known radon experts, especially the analysis of 13 European case–control studies by Darby et al. [2]. They underscore their basic argument that in Sweden, there is a 16 % increase in the risk of radoninduced lung cancer per 100 Bq/m. However, there appear to be logical mistakes in their reasoning, which are presented below. The first mistake concerns their chosen dose–response model. They determine the 16 % increase in risk per 100 Bq/m by using the linear no-threshold (LNT) hypothesis. According to this hypothesis, the excess risk increases linearly versus Bq/m (or vs. mSv effective dose) from zero to the maximum. There are no data that support the validity of this hypothesis over the whole range of doses. All existing studies are subject to a number of limitations. Moreover, there is a huge scatter in the results, so it is impossible to reach a coherent conclusion [3]. In fact, the LNT hypothesis has been criticized fundamentally in many independent studies [4]. The second fallacy—the ‘‘zero radon environment’’—is related to the previous one. The authors [1] widely invoke the value ‘‘0 Bq/m,’’ which makes no sense from both the All signers of this letter are members or associate members of SARI (Scientists for Accurate Radiation Information, http://radiationeffects. org/). The above letter represents the professional opinions of the signers and does not necessarily represent the views of their affiliated institutions.

Leukemia and Ionizing Radiation Revisited

A world-wide radiation health scare was created in the late 1950s to stop the testing of atomic bombs and block the development of nuclear energy. In spite of the large amount of evidence that contradicts the cancer predictions, this fear continues. It impairs the use of low radiation doses in medical diagnostic imaging and radiation therapy. This brief article revisits the second of two key studies, which revolutionized radiation protection, and identifies a serious error that was missed. This error in analyzing the leukemia incidence among the 195,000 survivors, in the combined exposed populations of Hiroshima and Nagasaki, invalidates use of the LNT model for assessing the risk of cancer from ionizing radiation. The threshold acute dose for radiation-induced leukemia, based on about 96,800 humans, is identified to be about 50 rem, or 0.5 Sv. It is reasonable to expect that the thresholds for other cancer types are higher than this level. No predictions or hints of excess cancer risk (or any other health risk) should be made for an acute exposure below this value until there is scientific evidence to support the LNT hypothesis.