Article

Health effects of low-level radiation in shipyard workers

Authors:
To read the full-text of this research, you can request a copy directly from the author.

Abstract

The Nuclear Shipyard Workers Study (NSWS) was designed to determine whether there is an excess risk of leukemia or other cancers associated with exposure to low levels of gamma radiation. The study compares the mortality experience of shipyard workers who qualified to work in radiation areas to the mortality of similar workers who hold the same types of jobs but who are not authorized to work in radiation areas. The population consists of workers from six government and two private shipyards.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the author.

... There are many epidemiological studies that demonstrate evidence for radiation hormesis (Luckey 1991), and Table 1 shows such studies for lung. The 13-yr U.S. Nuclear Shipyard Workers Study on the health effects of low-dose radiation was carried out by Johns Hopkins Department of Epidemiology (Matanoski 1991). In the study, a high-dose cohort of 27,872, low-dose cohort of 10,348, and a control cohort of 32,510 unexposed shipyard workers were examined from 1980-1988. ...
... Epidemiological studies that compare exposed and unexposed cohorts in the same company or workplace, where medical procedures for employment and employee health are similar, should best delineate the HWE from hormesis (Luckey 1991). The large size of the Nuclear Shipyard Worker Study and Wilkerson multi-facility studies for exposed and control cohorts provided powerful, statistically significant evidence for radiation hormesis (Matanoski 1991;Wilkinson et al. 2000). The PROFAC of 0.29 for all cancers in British radiologists compared to all other physicians' specialties also excludes the HWE (Berrington et al. 2001;Cameron 2002). ...
Article
Full-text available
Confounding factors in radiation pulmonary carcinogenesis are passive and active cigarette smoke exposures and radiation hormesis. Significantly increased lung cancer risk from ionizing radiation at lung doses < 1 Gy is not observed in never smokers exposed to ionizing radiations. Residential radon is not a cause of lung cancer in never smokers and may protect against lung cancer in smokers. The risk of lung cancer found in many epidemiological studies was less than the expected risk (hormetic effect) for nuclear weapons and power plant workers, shipyard workers, fluoroscopy patients, and inhabitants of high-dose background radiation. The protective effect was noted for low- and mixed high- and low-linear energy transfer (LET) radiations in both genders. Many studies showed a protection factor (PROFAC) > 0.40 (40% avoided) against the occurrence of lung cancer. The ubiquitous nature of the radiation hormesis response in cellular, animal, and epidemio-logical studies negates the healthy worker effect as an explanation for radiation hormesis. Low-dose radiation may stimulate DNA repair/apoptosis and immunity to suppress and eliminate cigarette-smoke-induced transformed cells in the lung, reducing lung cancer occurrence in smokers.
... Cameron also points to cohort studies of US shipyard workers [9,10] and British radiologists [11]. Cohort studies are less subject to confounding than are ecological studies. ...
... Matanoski et al [9,10] studied workers at US nuclear shipyards. They reported significantly lower standardized mortality rates (SMRs) in those overhauling nuclearpowered ships with cumulative effective doses greater than 5 mSv than in those with lower doses, and in the latter group compared with non-radiation shipyard workers. ...
Article
This paper presents little-known data to support the hypothesis that we need increased background radiation to improve our health. Attention will be drawn to results that demonstrate health benefits of ionizing radiation that have been largely ignored by the news media.
... What is seen, however, is that in case of low doses obtained at low dose rates – and this is the case of NPPs – there are no negative health effects to be found. A large study of nuclear workers in Shippingport in the US, lead by the Head of the Department of Epidemiology in a leading US University and peer reviewed by distinguished scientists at half a year intervals during the study, showed that cancer mortality among the group irradiated with low doses (above 5 mSv) was by 24% lower than in the control group consisting of workers from the same shipyard, who had not been irradiated during the work [27]. Owing to that choice of the control group from the same shipyard and doing the same kind of tasks it was possible to avoid " healthy worker effect " , so that the results of the study [27] are often quoted as the proof for beneficial effects of radiation. ...
... A large study of nuclear workers in Shippingport in the US, lead by the Head of the Department of Epidemiology in a leading US University and peer reviewed by distinguished scientists at half a year intervals during the study, showed that cancer mortality among the group irradiated with low doses (above 5 mSv) was by 24% lower than in the control group consisting of workers from the same shipyard, who had not been irradiated during the work [27]. Owing to that choice of the control group from the same shipyard and doing the same kind of tasks it was possible to avoid " healthy worker effect " , so that the results of the study [27] are often quoted as the proof for beneficial effects of radiation. In connection with the suggestions that the irradiation of parents can adversely influence health of the children, National Radiological Protection Board (NRPB) in UK performed multiyear studies and in November 1997 declared: " The results of the new large epidemiological study do not agree with the thesis that the exposure of parents to radiation before child inception is the reason for leukemia and non-Hodgkin lymphoma (LNHL) of the children " [30]. ...
Article
Nuclear safety is examined from the standpoint of accidents or events that might lead to release of a significant amount of radioactive material. Both nuclear power plants and fuel-cycle facilities are covered. Specific safety aspects of the various types of facilities are reviewed, and accident probabilities and consequences are considered. 17 references. (JWR)
... This paper provides information from the unpublished final report of the nuclear shipyard worker study (NSWS) (Matanoski, 1991), herein referred to as 'Final Report'. The NSWS is the world's largest and most thorough study of health effects of low-dose-rate ionising radiation to nuclear workers. ...
... deaths would have been expected (Final Report, p.332). Table 2 Deaths from All Causes, Death Rates** and Standardised mortality ratios with 95% confidence intervals for the cohort (NW = 5.0 mGy)); low dose cohort (NW < 5.0 mGy); and controls (NNW) (Matanoski, 1991). Table 3 presents a breakdown of deaths from various causes, which shows that SMRs from diseases of the circulatory system are significantly decreased in the cohort. ...
Article
This paper is a summary of the 1991 Final Report of the Nuclear Shipyard Worker Study (NSWS), a very comprehensive study of occupational radiation exposure in the US. The NSWS compared three cohorts: a high-dose cohort of 27,872 nuclear workers, a low dose cohort of 10,348 workers, and a control cohort of 32,510 unexposed shipyard workers. The cohorts were matched by ages and job categories. Although the NSWS was designed to search for adverse effects of occupational low dose-rate gamma radiation, few risks were found. The high-dose workers demonstrated significantly lower circulatory, respiratory, and all-cause mortality than did unexposed workers. Mortality from all cancers combined was also lower in the exposed cohort. The NSWS results are compared to a study of British radiologists. We recommend extension of NSWS data from 1981 to 2001 to get a more complete picture of the health effects of <sup align="right"> 60 </sup>Co radiation to the high-dose cohort compared to the controls.
... Mortality from all cancers combined was also lower in the exposed cohort. 22,23 Studies by the lead author on the Hiroshima atomic bomb survivors have revealed the acute threshold dose for the onset of radiation-induced leukemia to be quite high, about 1.1 Gy. 5,18 Lauriston Taylor, founder, and long-time president of the NCRP, proclaimed in his 1980 Sievert Lecture that studies "calculating the numbers of people who will die as a result of having been subjected to diagnostic X-ray procedures (using the LNT model) … These are deeply immoral uses of our scientific knowledge." 24 This case has limitations; it is not a case study with a rigorous experimental design. ...
Article
Full-text available
We report the case of a patient in Massachusetts with early-stage Alzheimer’s disease who was treated with low doses of ionizing radiation to the brain. He requested this treatment after reading about a patient with severe Alzheimer’s in Michigan who improved remarkably after receiving 4 CT scans. After his first treatment in April 2016, mental clarity improved. His impaired conversation, reading, and sense of humor were restored, especially his virtuosic clarinet jazz-playing. However, executive function remained deficient. He requested a treatment every 2 weeks, but his neurologist denied this, fearing opposition to this treatment, a diagnostic procedure that used ionizing radiation. Limited recovery was observed after each CT scan, lasting from several weeks to months, depending on the endpoints/behavior and the periodicity. Despite the positive responses, the physician was reluctant to continue beyond 6 due to concerns about adverse effects and disapproval for prescribing them. The patient began hyperbaric oxygen therapy as an alternative. But after 43 treatments, no conclusive benefit was observed. The patient died in September 2020 at age 77. This experience suggests CT scans may have value in treating Alzheimer’s patients and restoring, at least temporarily, important aspects of normal life activities. Such observations need testing and validation.
... (e) The final report of the large study of United States nuclear shipyard workers funded by the US Department of Energy showed that there was significantly lower total mortality in the exposed groups (both the < 5 mSv and ≧5 mSv groups) than in the non-radiation workers who engaged in similar work [17,18]. However, NCRP Report No. 136 discarded all of the data of this study on the basis of an undocumented flaw in selecting nuclear workers [19]. ...
Article
At the start of the 21st century, the most important task of the radiation protection community is to demonstrate that workers and members of the public have been adequately protected by the current dose limits. There is no evidence that natural radiations are causing adverse health effects in those high background radiation areas exceeding 10 mSv/y in India, Brazil and Iran. Evidence increasingly shows that there are threshold effects in risk of radiation. An evolved system of radiological protection with a “practical” threshold concept will be an alternative to the current system based on the linear-no-threshold (LNT) hypothesis. “Practical” thresholds may be defined as dose levels below which induction of detectable radiogenic cancers or hereditary effects are not expected. If the current dose limits are assumed to be below “practical” thresholds, there may be no need of “justification” and “optimization” (ALARA) principles for occupational and public exposures in normal situations.
... In my opinion, the best epidemiologic study of radiation workers ever performed is the U.S. Department of Energysupported nuclear shipyard worker study (1980 -1988) (7). The 28,000 nuclear shipyard workers with the largest cumu-lative doses had a death rate from all causes 24% lower than did the 32,000 age-matched and job-matched unexposed shipyard workers. ...
Article
I believe that longevity is a better measure of the health effects of radiation than is cancer mortality.
... The thirteen-year U.S. Nuclear Shipyard Workers study of the health effects of low-dose radiation was performed by the Johns Hopkins Department of Epidemiology, School of Public Health and Hygiene, reported to the Department of Energy in 1991 (Matanoski, 1991) and reported in UNSCEAR 1994. Arthur C. Upton, who concurrently chaired the National Academy of Sciences BEIR V Committee on " Health Effects of Exposure to Low Levels of Ionizing Radiation " (NAS 1990), chaired the Technical Advisory Panel that advised on the research and reviewed the results. ...
The prime concern of radiation protection policy since 1959 has been protecting DNA from damage. The 1995 NCRP Report 121 on collective dose states that since no human data provides direct support for the linear no threshold hypothesis (LNT), and some studies provide quantitative data that, with statistical significance, contradict LNT, ultimately, confidence in LNT is based on the biophysical concept that the passage of a single charged particle could cause damage to DNA that would result in cancer. Current understanding of the basic molecular biologic mechanisms involved and recent data are examined before presenting several statistically significant epidemiologic studies that contradict the LNT hypothesis. Over eons of time a complex biosystem evolved to control the DNA alterations (oxidative adducts) produced by about 10(10) free radicals/cell/d derived from 2-3% of all metabolized oxygen. Antioxidant prevention, enzymatic repair of DNA damage, and removal of persistent DNA alterations by apoptosis, differentiation, necrosis, and the immune system, sequentially reduce DNA damage from about 10(6) DNA alterations/cell/d to about 1 mutation/cell/d. These mutations accumulate in stem cells during a lifetime with progressive DNA damage-control impairment associated with aging and malignant growth. A comparatively negligible number of mutations, an average of about 10(-7) mutations/cell/d, is produced by low LET radiation background of 0.1 cGy/y. The remarkable efficiency of this biosystem is increased by the adaptive responses to low-dose ionizing radiation. Each of the sequential functions that prevent, repair, and remove DNA damage are adaptively stimulated by low-dose ionizing radiation in contrast to their impairment by high-dose radiation. The biologic effect of radiation is not determined by the number of mutations it creates, but by its effect on the biosystem that controls the relentless enormous burden of oxidative DNA damage. At low doses, radiation stimulates this biosystem with consequent significant decrease of metabolic mutations. Low-dose stimulation of the immune system may not only prevent cancer by increasing removal of premalignant or malignant cells with persistent DNA damage, but used in human radioimmunotherapy may also completely remove malignant tumors with metastases. The reduction of gene mutations in response to low-dose radiation provides a biological explanation of the statistically significant observations of mortality and cancer mortality risk decrements, and contradicts the biophysical concept of the basic mechanisms upon which, ultimately, the NCRPs confidence in the LNT hypothesis is based.
... If the data from just one of the 15 countries, Canada, are excluded, the excess risk is no longer statistically different from zero Many other studies have been reported on cancer risk vs dose for such normal occupational exposures. In response to heavy media coverage of some non-scientific reporting, a $10 million study (Matanoski 1991) was carried out by the U.S. Center for Disease Control and Prevention of workers in eight U.S. Navy shipyards involved in servicing nuclear-propelled ships. The study included 28,000 exposed workers and 33,000 age-and job-matched controls who worked on non-nuclear ships. ...
Article
The various lines of evidence that lead to current estimates of the cancer risk from low-level radiation are reviewed. It is first shown why it is very difficult to get direct experimental evidence, so that much reliance is placed on extrapolation of data from high level radiation. The evidence that a linear extrapolation is conservative, i.e. more likely to over-estimate than to under-estimate the risk at low levels, is extensively reviewed. The 'new evidence' that has been claimed to indicate that the linear extrapolation under-estimates effects at low levels is examined. Complications in deriving risks based on the linearity assumption are considered, and final estimates from various sources are presented.
... If the data from just one of the 15 countries, Canada, are excluded, the excess risk is no longer statistically different from zero Many other studies have been reported on cancer risk vs dose for such normal occupational exposures. In response to heavy media coverage of some non-scientific reporting, a $10 million study (Matanoski 1991) was carried out by the U.S. Center for Disease Control and Prevention of workers in eight U.S. Navy shipyards involved in servicing nuclear-propelled ships. The study included 28,000 exposed workers and 33,000 age-and job-matched controls who worked on non-nuclear ships. ...
Chapter
It is commonly stated that “any radiation dose, no matter how small, can cause cancer.” The basis for that statement is the linear no-threshold theory (LNT) of radiation carcinogenesis. According to LNT, if 1 Gy (100 rad) of exposure gives a cancer risk R, the risk from 0.01 Gy (1 rad) of exposure is R/100, the risk from 0.00001 Gy (1 mrad) is R/100,000, and so on. Thus the cancer risk is not zero regardless of how small the exposure. However, in recent years, a strong sentiment has developed in the community of radiation health scientists to regard risk estimates in the low-dose region based on LNT as being grossly exaggerated or completely negligible. For example, the 6000-member Health Physics Society, the principal organization for radiation protection scientists, issued a position paper (Health Physics Society 1996) stating “Below 10 rad ... risks of health effects are either too small to be observed or are non-existent.” A similar position statement was issued by American Nuclear Society.
... W innym studium zbadano wpływ promieniowania na dużą grupę 28 000 pracowników stoczni Shippingport, w której remontowano okręty o napędzie jądrowym. Stwierdzono, że umieralność na raka wśród osób napromieniowanych niskimi dawkami (powyżej 5 mSv) była o 24% mniejsza niż w grupie kontrolnej złożonej z pracowników tej samej stoczni, którzy nie byli napromieniowani [22] Shippingport takie tłumaczenie jest niemożliwe, bo nie ma powodu dla którego pracownicy tej samej stoczni mieliby być "zdrowymi pracownikami" w grupie pracującej na okrętach z napędem jądrowym , a "niezdrowymi" w grupie pozostałych stoczniowców. ...
... The US Department of Energy published in 1994 a large study on mortality rates from a variety of causes among the shipyard workers, some of who were assigned, in comparable number, to nuclear vessels and others to conventional vessels [7]. Like in many reports of that nature, the results are given in tables and actual differences in mortality rates are difficult to visualize. ...
Article
Full-text available
The International Centre for Low-Dose Radiation Research (ICLDRR) has assembled, in a single database, all published results from experimental radiation carcinogenesis in mammals. The database contains experimental conditions and outcomes for about 87,000 exposed animals (˜ 60,000 cancers) and 40,000 controls (˜ 19,000 cancers). Experiments were conducted with all types of ionizing radiation, at doses starting at 10 mGy for gamma radiation, 40 mGy for X- rays, 2 mGy for beta radiation, 2 mGy for alpha radiation, and 5 mGy for neutrons. The data form 748 datasets, each providing a dose-response curve for a particular species, strain, sex, age at exposure exposed to a range of doses under specific exposure conditions. No cancers were observed in the control groups of about 30% of the datasets. When cancers were observed in control animals, no effect or an apparent reduction in cancer risk were observed in 40% of the neutron datasets, 50% of the X-rays datasets, 53% of the gamma datasets, and 61% of the alpha datasets. Apparent reductions in cancer rate, significant at up to 10 standard deviations were observed in mice exposed to 100 and 250 mGy of gamma radiation. It is confirmed that, in some experiments, exposed animals live considerably longer (up to 40%) than their controls. The frequency of lack of effect, protective effects or increased longevity in exposed animals challenges the general validity of the Linear No Threshold hypothesis (LNT). For comparison, clear beneficial effects observed in the US shipyard nuclear workers and anomalies in uranium mine dosimetry leading to overestimated radon risk are also examined.
... A related problem arises at all doses below about 0.3 Sv, where the four data points, either on a point-by-point basis or as an ensemble, repudiate the predictions of the linear no-threshold model. This result is confirmed by other refutations of the linear model (6,8,19,20,(38)(39)(40), making it untenable at low doses. ...
Article
Full-text available
The linear no-threshold model for radiation effects was introduced as a conservative model for the design of radiation protection programs. The model has persisted not only as the basis for such programs, but has come to be treated as a dogma and is often confused with scientific fact. In this examination a number of serious problems with the linear no-threshold model of radiation carcinogenesis were demonstrated, many of them invalidating the hypothesis. It was shown that the relative risk formalism did not approach 1 as the dose approaches zero. When morality ratios were used instead, the data in the region below 0.3 Sv were systematically below the predictions of the linear model. It was also shown that the data above 0.3 Sv were of little use in formulating a model at low doses. In addition, these data are valid only for doses accumulated at high dose rates, and there is no scientific justification for using the model in low-dose, low-dose-rate extrapolations for purposes of radiation protection. Further examination of model fits to the Japanese survivor data were attempted. Several such models were fit to the data including an unconstrained linear, linear-square root, and Weibull, all of which fit the data better than the relative risk, linear no-threshold model. These fits were used to demonstrate that the linear model systematically over estimates the risk at low doses in the Japanese survivor data set. It is recommended here that an unbiased re-analysis of the data be undertaken and the results used to construct a new model, based on all pertinent data. This model could then form the basis for managing radiation risks in the appropriate regions of dose and dose rate.
... Table 1 Standardized mortality ratios for all causes of death and for malignant neoplasms for nuclear energy workers. (Adapted from The SMR for "all causes of death" in nuclear shipyard workers compared with non-nuclear shipyard workers is significantly low (SMR = 0.76 in Table 1; UNSCEAR 1994a; Matanowski 1991), but this value is significantly low primarily because the non-nuclear workers (the comparison, control group) had a higher incidence of deaths from disease other than cancer (UNSCEAR 1994a). Both groups had lower death rates than the general US population for leukemia, and for lymphatic and haemopoietic cancers (UNSCEAR 1994b, Table 41), but it would be misleading to attribute this to a protective effect of radiation: a low dose sub-cohort tends to be weighted towards younger employees, and the HWE is known to decrease with increasing length of employment. ...
Article
There is a vigorous debate about whether or not there may be a "threshold" for radiation-induced adverse health effects. A linear-no threshold (LNT) model allows radiation protection practitioners to manage putative risk consistently, because different types of exposure, exposures at different times, and exposures to different organs may be summed. If we are to argue to regulators and the public that low doses are less dangerous than we presently assume, it is incumbent on us to prove this. The question is therefore whether any consonant body of evidence exists that the risk of low doses has been over-estimated. From the perspectives of both health physics and radiobiology, we conclude that the evidence for linearity at high doses (and arguably of fairly small total doses if delivered at high dose rate) is strong. For low doses (or in fact, even for fairly high doses) delivered at low dose rate, the evidence is much less compelling. Since statistical limitations at low doses are almost always going to prevent a definitive answer, one way or the other, from human data, we need a way out of this epistemological dilemma of "LNT or not LNT, that is the question". To our minds, the path forward is to exploit (1) radiobiological studies which address directly the question of what the dose and dose rate effectiveness factor is in actual human bodies exposed to low-level radiation, in concert with (2) epidemiological studies of human populations exposed to fairly high doses (to obtain statistical power) but where exposure was protracted over some years.
... Most of the excess was related to the PNS site, which exhibited very large SMRs that increased monotonically with employment duration. This is consistent with observations in a study of mesothelioma risk in a group of U.S. Navy nuclear shipyards (43). A nested case-control study of lung cancer among PNS workers (44) found that adjustment for asbestos and welding fume decreased the ERR per 10 mSv estimate from 3.6% to 1.9%, therefore it appears that confounding by exposure to these agents is likely at the PNS site, for lung cancer. ...
Article
Unlabelled: Nuclear workers worldwide have been studied for decades to estimate associations between their exposure to ionizing radiation and cancer. The low-level exposure of these workers requires pooling of large cohorts studied over many years to obtain risk estimates with appropriate latency and good precision. We assembled a pooled cohort of 119,195 U.S. nuclear workers at four Department of Energy nuclear weapons facilities (Hanford site, Idaho National Laboratory, Oak Ridge National Laboratory and Savannah River site) and at the Portsmouth Naval Shipyard. The cohort was followed at the start of the workers beginning their radiation work (at earliest, between 1944 and 1952) through 2005, and we compared its mortality to that of the U.S. Population: We also conducted regression-modeling analysis to evaluate dose-response associations for external radiation exposure and outcomes: all cancers, smoking- and nonsmoking-related cancers, all lymphatic and hematopoietic cancers, leukemia (excluding chronic lymphocytic), multiple myeloma, cardiovascular disease and others. The mean dose observed among the cohort was 20 mSv. For most outcomes, mortality was below expectation compared to the general population, but mesothelioma and pleura cancers were highly elevated. We found an excess relative risk (ERR) per 10 mSv of 0.14% [95% confidence interval (CI): -0.17%, 0.48%] for all cancers excluding leukemia. Estimates were higher for nonsmoking-related cancers (0.70%, 95% CI: 0.058%, 1.5%) and lower for smoking-related cancers (-0.079%, 95% CI: -0.43%, 0.32%). The ERR per 10 mSv was 1.7% (95% CI: -0.22%, 4.7%) for leukemia, which was similar to the estimate of 1.8% (95% CI: 0.027%, 4.4%) for all lymphatic and hematopoietic cancers. The ERR per 10 mSv for multiple myeloma was 3.9% (95% CI: 0.60%, 9.5%). The ERR per 10 mSv for cardiovascular disease was 0.026% (-0.25%, 0.32%). Little evidence of heterogeneity was seen by facility, birth cohort or sex for most outcomes. The estimates observed here are similar to those found in previous large pooled nuclear worker studies and also (with the exception of multiple myeloma) to those conducted in the Life Span Study of Japanese atomic bomb survivors. The tendency of observed risks to persist many years after exposure for most outcomes illustrates the importance of continued follow-up of nuclear worker cohorts.
... (18) The 'Final Report' was issued in 1991. (19) however, the scientists who did the research chose not to publish the details of this excellent study in any journal. ...
Article
Full-text available
The 1953 Atoms for Peace Speech to the United Nations proposed applying nuclear energy to essential needs, including abundant electrical energy. The widespread fear of ionizing radiation from nuclear facilities and medical procedures began after the United States National Academy of Sciences performed a study of radiation dangers to the human genome. This study, initiated and managed by an oil industry benefactor, recommended in 1956 that the risk of radiation-induced mutations be assessed using the linear no-threshold dose-response model instead of the threshold model. It was followed by a study that wrongly linked low radiation to cancer among the atomic bomb survivors. The ensuing controversy resulted in a compromise. The National Committee on Radiation Protection adopted the precautionary principle policy in 1959, justified by fear of cancer and lack of knowledge. The United States and all other countries followed this recommendation, which remains unchanged 62 years later. Its impact on nuclear energy and medicine has been profound. Many costly regulations have been enacted to prevent very unlikely human or equipment failures—failures that would lead to radiation exposures that are below the dose thresholds for lasting harmful effects. Potential low-dose radiation therapies, against inflammation, cancer, autoimmune, and neurodegenerative diseases, are shunned.
... In the study, the deaths of the nuclear workers from all causes were reported in 16 standard deviations which was lower than the controls. Eric J. Hall, proponent of nothreshold dose value, claimed that all ionization radiation may cause to cancer (Matanoski 1991;USDOE 1991). ...
Book
Full-text available
Radioactivity can be found at different levels in various environments such as soil, rock, water food and in air. In principle, the source of environmental radioactivity can be classified into two groups named natural and manmade. Natural radiation sources can have cosmic or terrestrial origin. Terrestrial radiation sources originate from primordial radionuclides in the earth's crust that have existed since the beginning of the world. The most important primordial radionuclides in terms of radiological risk for humans are 40K, 238U, 232Th and their decay products of both natural radioactive series. 87Rb and 235U are second-rate primordial radionuclides, to be neglected by their contribution to the human dose. Generally, the concentrations of natural radionuclide activity observed in soils reflect the natural background concentrations of the rocks from which they are derived. On the other hand, human activities such as burning of coal to provide electrical energy and application of artificial fertilizers containing phosphates to increase agricultural production causes the enrichment of natural radioactivity concentrations in the environment. Naturally occurring radioactivity is of immediate and crucial concern to the people and authorities responsible for environmental protection. Because of this reason many studies and projects have been devoted for determining and monitoring of radiation levels in various environments. Continued studies on the radiation levels in various environments either from natural radiation sources or releasing radionuclides into the environment by human activities can contribute to our knowledge about radiation risk and dangers of radiation. The studying of environmental radiation levels in Turkey goes back to three decades before it was not more. After the Chernobyl Nuclear Power Plant accident in 1986 triggered many investigations on radiation levels in various environments of Turkey because Turkey is a possible candidate (in particular northern part of Turkey) for to be e􀄀ecting from the accident geographically. We may say that this disaster has opened the mind of Turkish researchers, communities and authorities by means of hazards of radiation. Furthermore, there are two planned nuclear power plants in Turkey named Akkuyu and Sinop Nuclear Power Plant, Akkuyu Nuclear Power Plant is under construction now. Most of the environmental radiation studies in the close areas of planned nuclear power plants had been done for filling the data of background radiation levels in Turkey before start of operation of these nuclear power plants. Many excellent works have been noticed and devoted for investigation of radiation levels in various Turkish environments originated either from natural and manmade radiation sources during recent three decades. The motivation to edit this monograph was for collecting and reviewing the data of environmental radioactivity of Turkey in a single book. In this monograph, radioactivity in various environment of Turkey has been reviewed with light of previous published research papers are discussed in detail. Also some chapters contain newly measured environmental radiation data together with their health risks for humans. In the first chapter of the book, fundamental concepts of radiation, radioactivity, radionuclides and radiation in various environments are introduced. Because fundamental knowledge about radiation and radionuclides which causes radioactivity in air, water, soil, and in rocks, is very important for deeper understanding about nature of environmental radioactivity, it is a good suggestion for the readers who don't have deeper knowledge about radiation and radioactivity. In the second chapter, detection methods of radioactivity used in Turkish environmental studies have been discussed in detail and it can be considered as to be educational chapter which can be useful for understanding of sampling methods and tools for environmental radiation measurements. Fallowing two chapters have given detailed lights about radioactivity in Turkish soil and food. Natural radioactivity levels of various regions of Turkey have also given in some chapters of the book. The book also contains detailed chapters related with a new approach to predicting natural radiation levels in environments by using artificial intelligence method and measurement uncertainty associated with activity of alpha emitted radionuclides in the environment. Furthermore, there can be found a chapter covers usage of polychaeta species as biomonitor for heavy metal pollution in the marine environments. We hope that this book can be useful for readers who are willing to gain information about radioactivity levels in various environments of Turkey and young researchers to understand sampling and measurements methods for environmental radiation studies. Drs. Tuncay Bayram, Dharmendra K. Gupta and Yevhen Zayachuk, individually acknowledge all authors for contributing their valuable time, information and interest to bring this book into its current form.
... Significantly lower mortality from all causes was observed among those exposed to an average dose rate of 7.59 mGy per year than among the controls (standard mortality ratio ¼ 0.76, with 95% confidence interval from 0.73 to 0.79). 11,12 Determination of the lifelong dose-rate threshold for harmful effects is impossible because humans may not be exposed, whole-body, to high radiation levels. However, lifelong studies have been carried out on beagle dogs, which are a good model for humans and live no longer than 20 years. ...
Article
Full-text available
Our return to a study on dogs exposed lifelong to cobalt-60 γ-radiation was prompted by a comment that data in dog studies have large statistical errors due to the small number of dogs. We located an earlier article on the same study that had a better mortality curve for the dogs in each dose-rate group. The median life span of the dogs in each group was tabulated, and the standard error of each was calculated. No statistically significant shortening of median life span was observed for the lowest dose-rate group at any reasonable significance level (P value:.005-.05), whereas for dogs with higher irradiation rates, life span shortening was statistically significant at highest reasonable significance level (P value:.005). The results were entered on a graph of life span versus dose rate, assuming a threshold dose–response model. The fitted line indicates that the dose-rate threshold for γ-radiation induced life span reduction is about 600 mGy per year, which is close to the value we found previously. Making allowance for the calculated standard errors, we conclude that this threshold is in the range from 300 to 1100 mGy per year. This evidence is relevant for emergency measures actions (evacuation of residents) and for nuclear waste management.
... d Mortality of 10,000 occupants of 1,700 60 Co-contaminated apartments in Taiwan who received a mean yearly dose of 49 mSv or an accumulated dose of 400 mSv during their total stay (lower curve) versus mortality in the general population (upper curve). In the exposed population, the rate of congenital malformations was only 7% of that in the general population [10] in non-nuclear workers, a difference of 16 standard deviations, and that the ratios for death due to all malignant neoplasms were 0.95 and 1.12 (p < 0.001), respectively, a difference of four standard deviations [16]. Authoritative boards such as the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the National Academy of Sciences (NAS) in its Biological Effects of Ionizing Radiation (BEIR) reports have been well aware of the difficulties in acquiring Breliable information about the correlation between small doses and their effects either in individuals or in large populations^, but have consistently sought to minimize the significance of this by statements such as the following in BEIR VII from 2006: Bthe committee concludes that the preponderance of information indicates that there will be some risk, even at low doses^ [17]. ...
... There was a 66% decrease in the death rate from infection and parasitic disease in exposed workers at the Savannah River Plant when compared with unexposed controls within the same area 105 . It was 14% less for Shipyard workers [27][28] . ...
Chapter
Full-text available
The health benefits from low dose ionizing radiation are many, that proceed beyond the benefits of preventing many diseases and prolonging lifespan or even reversing aging. Moderate doses of X-rays from 0.5-3.0 Gy were successfully used in the first half of the 20th century to treat many inflammatory and infectious diseases. Low dose radiation (LDR) may also be effective in treating viral infections such as hepatitis and HIV/AIDS, as well as difficult to treat infections like MRSA. A few cases of neurodegenerative disease (AD, PD) have responded to a series of brain CT scans. The addition of LDR to high dose radiotherapy or chemotherapy has significantly improved survival for non-Hodgkins lymphoma and other tumor types. The use of radioactive pads (Chapter 7) is also effective in treating a wide variety of health issues.
... SMR ratios for selected causes of death among nuclear and non-nuclear shipyard workers who received the same level of medical care[88][89] .(With kind permission by Springer, Charles L Sanders: Radiation Hormesis and the Linear-No-Threshold Assumption, © 2010). ...
Chapter
Full-text available
The LNT is a scientific scandal associated with deception, fraud, hyperbole, political spin and statistical manipulation. Radio-phobia resulting from application of the LNT in the Chernobyl and Fukushima incidents have resulted in thousands of deaths in the elderly and unborn. Muller’s deception and Russell’s mistake in mutation studies with fruit flies and mice promoted the LNT which was then force-fitted into hundreds of epidemiological studies. A critical mass of radiation scientists has come together under S.A.R.I. to confront and educate.
... 183,189,[199][200][201][202] Actually, below a certain level of exposure, there are beneficial health effects, (termed radiation hormesis), which do not follow from extrapolation of the high-dose portion of the curve. 182,[189][190][191][203][204][205][206][207][208][209][210][211][212][213][214][215][216][217] Structural Rehabilitation Protocols While other methods may provide evidence for structural rehabilitation, we discuss only recent research outcomes in CBP ® Technique. CBP ® is unique in chiropractic, in that it utilizes a "mirror image®" concept applied to human posture; this basic tenet has a sound foundation in Linear Algebra, an area of study common to both engineering and mathematics. ...
Article
Full-text available
Although practice protocols exist for SMT and functional rehabilitation, no practice protocols exist for structural rehabilitation. Traditional chiropractic practice guidelines have been limited to acute and chronic pain treatment, with limited inclusion of functional and exclusion of structural rehabilitation procedures. (1) To derive an evidence-based practice protocol for structural rehabilitation from publications on Clinical Biomechanics of Posture (CBP((R))) methods, and (2) to compare the evidence for Diversified, SMT, and CBP((R)). Clinical control trials utilizing CBP(R) methods and spinal manipulative therapy (SMT) were obtained from searches in Mantis, CINAHL, and Index Medicus. Using data from SMT review articles, evidence for Diversified Technique (as taught in chiropractic colleges), SMT, and CBP((R)) were rated and compared. From the evidence from Clinical Control Trials on SMT and CBP((R)), there is very little evidence support for Diversified (our rating = 18), as taught in chiropractic colleges, for the treatment of pain subjects, while CBP((R)) (our rating = 46) and SMT for neck pain (rating = 58) and low back pain (our rating = 202) have evidence-based support. While CBP((R)) Technique has approximately as much evidence-based support as SMT for neck pain, CBP((R)) has more evidence to support its methods than the Diversified technique taught in chiropractic colleges, but not as much as SMT for low back pain. The evolution of chiropractic specialization has occurred, and doctors providing structural-based chiropractic care require protocol guidelines for patient quality assurance and standardization. A structural rehabilitation protocol was developed based on evidence from CBP((R)) publications.
... Wymieniae tu nale¿y m.in. pracowników z Francji [6][7], amerykañskiego oœrodka w Portmouth [8], pracowników kanadyjskich [9][10], pracowników fabryki broni Pantex [11], brytyjskich radiologów [12] , amerykañskich i japoñskich techników radiologicznych [13][14] oraz stoczniowców [15][16] . Bardzo wiele danych wskazuje na nieznacz¹cy statystycznie spadek iloœci nowotworów [5]. ...
Article
Full-text available
Millions of workers employed in the nuclear industry have been exposed to chronic low LET radiation, mostly to cumulative doses <100 mSv [1, 2]. A chronic threshold dose of ~10 mSv/day or ~200 mSv/year was found to cause an excess relative risk (ERR) for all solid cancers in irradiated human populations [3–7]. Luckey was the first to find a bioposi-tive effect of ionizing radiation on cancer formation in nuclear workers (Table 6.1) [1]. A similar study published 17 years later found similar results, that cancer mortality among nuclear workers receiving cumulative lifetime doses of <100 mSv experienced less cancer mortality (Table 6.2).
Article
Full-text available
A retrospective cohort mortality study was conducted of workers engaged in nuclear technology development and employed for at least 6 months at Rocketdyne (Atomics International) facilities in California, 1948-1999. Lifetime occupational doses were derived from company records and linkages with national dosimetry data sets. International Commission on Radiation Protection (ICRP) biokinetic models were used to estimate radiation doses to 16 organs or tissues after the intake of radionuclides. Standardized mortality ratios (SMRs) compared the observed numbers of deaths with those expected in the general population of California. Cox proportional hazards models were used to evaluate dose-response trends over categories of cumulative radiation dose, combining external and internal organ-specific doses. There were 5,801 radiation workers, including 2,232 monitored for radionuclide intakes. The mean dose from external radiation was 13.5 mSv (maximum 1 Sv); the mean lung dose from external and internal radiation combined was 19.0 mSv (maximum 3.6 Sv). Vital status was determined for 97.6% of the workers of whom 25.3% (n = 1,468) had died. The average period of observation was 27.9 years. All cancers taken together (SMR 0.93; 95% CI 0.84-1.02) and all leukemia excluding chronic lymphocytic leukemia (CLL) (SMR 1.21; 95% CI 0.69-1.97) were not significantly elevated. No SMR was significantly increased for any cancer or for any other cause of death. The Cox regression analyses revealed no significant dose-response trends for any cancer. For all cancers excluding leukemia, the RR at 100 mSv was estimated as 1.00 (95% CI 0.81-1.24), and for all leukemia excluding CLL it was 1.34 (95% CI 0.73-2.45). The nonsignificant increase in leukemia (excluding CLL) was in accord with expectation from other radiation studies, but a similar nonsignificant increase in CLL (a malignancy not found to be associated with radiation) tempers a causal interpretation. Radiation exposure has not caused a detectable increase in cancer deaths in this population, but results are limited by small numbers and relatively low career doses.
Article
My purpose is to promote harmony with nature and to improve our quality of life with the knowledge that cancer mortality rates decrease following exposure to low dose irradiation. Hormesis (Greek HORMO = I excite) is the stimulation of any system by low doses of any agent. Hormology is the study of excitation. Low doses of many agents evoke a biopositive effect ; large doses produce a bionegative effect. The message is simple : small and large doses induce opposite physiologic results.
Article
Recent analyses of mortality among atomic bomb survivors have suggested a linear dose-response relationship between ionizing radiation and diseases of the circulatory system for exposures in the range 0-4 Sv. If confirmed, this has substantial implications. We have therefore reviewed the published literature to see if other epidemiological data support this finding. Other studies allowing a comparison of the rates of circulatory disease in individuals drawn from the same population but exposed to ionizing radiation at different levels within the range 0-5 Gy or 0-5 Sv were identified through systematic literature searches. Twenty-six studies were identified. In some, disease rates among those exposed at different levels may have differed for reasons unrelated to radiation exposure, while many had low power to detect effects of the relevant magnitude. Among the remainder, one study found appreciable evidence that exposure to low-dose radiation was associated with circulatory diseases, but five others, all with appreciable power, did not. We conclude that the other epidemiological data do not at present provide clear evidence of a risk of circulatory diseases at doses of ionizing radiation in the range 0-4 Sv, as suggested by the atomic bomb survivors. Further evidence is needed to characterize the possible risk.
Article
A retrospective follow-up study is in progress of mortality and morbidity among persons who reportedly received greater than or equal to 5 rem [50 millisieverts (mSv)] of penetrating ionizing radiation in any calendar year of employment at all facilities operated for the U.S. Department of Energy (DOE) or its predecessor agencies. The purpose is to identify any adverse health outcomes and to determine if any such outcomes are related to prior occupational radiation exposure at these facilities. A population of 3145 present and former civilian employees at DOE facilities and at the U.S. Navy's Nuclear Reactor Propulsion Program (NRPP) who meet the radiation exposure criteria were identified from personnel radiation monitoring records maintained at the facilities for the years 1943 through 1978. Vital status through 1984 was determined for 86.6 percent of this population; 588 deaths (18.6%) were observed. The median career external radiation dose for individuals in the population through 1978 was 153.4 mSv, with a collective dose of 718.0 person-Sv. The median duration of follow-up was 20 years, with a total of approximately 69,000 person-years. Using comparable age/race/gender groups in the U.S. general population as the standards, mortality through 1984 was examined for all white males (N = 2392) and for two subcohorts of this group for whom vital status was known for more than 90 percent: black males (N = 131), and other males for whom no race data were available (N = 280). The remainder of the population comprised 25 females and 317 persons for whom race and gender data were unavailable. The overall mortality experience of the total white male cohort was consistent with a healthy worker effect. Standardized mortality ratios (SMRs) for all causes of death combined (SMR = 0.88) and diseases of the circulatory (SMR = 0.78) and digestive (SMR = 0.52) systems were statistically significantly decreased. Mortality due to all cancers combined was similar to that of the comparison group (SMR = 1.09). There were no statistically significant differences in mortality due to cancers of the major organ systems, including those strongly associated with exposure to high levels of radiation in other populations. Mortality increases observed for non-Hodgkin's lymphoma (SMR = 2.26) and all lymphatic malignancies combined (SMR = 1.46) were not statistically significant. Three of the five deaths in the “other lymphatic malignancy” category were due to multiple myeloma; there were no deaths due to Hodgkin's lymphoma, malignant bone disease, or cancer of the thyroid gland. Lung cancer mortality (SMR = 1.09) was as expected. No significant deviations in mortality experience were observed within the two white male subcohorts nor in the other race/gender groups evaluated, except that there were no deaths due to leukemia in either of the white male subcohorts. Further analyses and follow-up of this population are dependent on the research interests of the responsible agencies.
Article
Radiation hormesis is reviewed with emphasis on its expression in the immune system. The shape of the dose-response relationship of the immune functions depends on a number of factors, chiefly the target cell under study, experimental design with emphasis on the dose range, dose spacing, dose rate and temporal changes, as well as the animal strain. For mouse and human T lymphocyte functions in the dose range of 0.01 to 10 Gy a J or inverted J-shaped curve is usually observed. For the more radioresistant macrophages, stimulation of many of their functions is often observed in the dose range up to a few grays. The cellular and molecular mechanisms of the enhancement of immunity induced by low-dose radiation were analyzed on the basis of literature published in the last decade of the past century. Intercellular reactions among the APCs and lymphocytes via distinct changes in expression of relevant surface molecules and secretion of regulatory cytokines in response to different doses of radiation were described. The major signal transduction pathways activated in response to these intercellular reactions were illustrated. The suppressive effect of low-dose radiation on cancer induction, growth, and metastasis and its immunologic mechanisms were analyzed. The present status of research in this field gives strong support to radiation hormesis in immunity with low-dose radiation as one of the mechanisms of cancer surveillance. Further research with new techniques using microarray with biochips to fully elucidate the molecular mechanisms is suggested.
Article
The ongoing debate over the possible beneficial effects of ionising radiation on health, hormesis, is reviewed from different perspectives. Radiation hormesis has not been strictly defined in the scientific literature. It can be understood as a decrease in the risk of cancer due to low-dose irradiation, but other positive health effects may also be encompassed by the concept. The overwhelming majority of the currently available epidemiological data on populations exposed to ionising radiation support the assumption that there is a linear non-threshold dose-response relationship. However, epidemiological data fail to demonstrate detrimental effects of ionising radiation at absorbed doses smaller than 100-200 mSv. Risk estimates for these levels are therefore based on extrapolations from higher doses. Arguments for hormesis are derived only from a number of epidemiological studies, but also from studies in radiation biology. Radiobiological evidence for hormesis is based on radio-adaptive response; this has been convincingly demonstrated in vitro, but some questions remain as to how it affects humans. Furthermore, there is an ecologically based argument for hormesis in that, given the evolutionary prerequisite of best fitness, it follows that humans are best adapted to background levels of ionising radiation and other carcinogenic agents in our environment. A few animal studies have also addressed the hormesis theory, some of which have supported it while others have not. To complete the picture, the results of new radiobiological research indicate the need for a paradigm shift concerning the mechanisms of cancer induction. Such research is a step towards a better understanding of how ionising radiation affects the living cell and the organism, and thus towards a more reliable judgement on how to interpret the present radiobiological evidence for hormesis.
Article
Scitation is the online home of leading journals and conference proceedings from AIP Publishing and AIP Member Societies
Article
Purpose: The risk of mesothelioma, including cancers of the pleura and peritoneum, was examined within two large cohorts of workers monitored for exposure to ionizing radiation. Methods and materials: Mortality was assessed among 253,632 workers routinely monitored for external radiation, including 30,724 industrial radiographers (IR) at shipyards, 142,583 workers at nuclear power plants (NPP), and 83,441 IR who had not worked at a NPP or shipyard. Follow-up was from 1969 through 2011. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were computed; observed numbers of deaths from mesothelioma (including cancers of the pleura and peritoneum) and asbestosis were compared with numbers expected based on age-, sex-, and calendar year-specific national mortality rates. Job history and quantitative asbestos exposure data were unavailable, but work at a shipyard was taken as a surrogate for the likelihood of exposure. Cox proportional hazards models were used to estimate hazard ratios (HRs) for mesothelioma in relation to estimated cumulative radiation exposure to the lung. Results: The mean duration of follow-up was 25.3 y (max 42 years). The mean cumulative lung dose was 28.6 mGy (7.3% > 250 mGy). Nearly 20% of the workers had died by 2011. A total of 421 mesothelioma deaths were found (75% occurring after 1999) with increased SMRs among workers monitored in shipyards (SMR 9.97; 95% CI 8.50-11.63) and for NPP workers (SMR 5.55; 95% CI 4.88-6.29), but not for IR who had not worked in shipyards (SMR 1.15; 95% CI 0.53-2.19). Likewise, deaths from asbestosis (n = 189) were also increased for shipyard and NPP workers (SMR =18.1 and 9.2, respectively), but not among workers who never worked at a shipyard or NPP (SMR =0.70; n = 1). Radiation dose to the lung was not associated with a statistically meaningful dose-response trend for mesothelioma in the combined cohorts (HR at 100 mGy =1.10; 95% CI 0.96-1.27; p = 0.18), nor was mesothelioma risk associated with radiation exposure among IR who had not worked in a shipyard and assumed minimally exposed to asbestos. Conclusions: An elevated rate of death from mesothelioma was observed in two radiation-exposed occupational groups with potential for asbestos exposure. The increased risk of death from asbestosis, combined with little evidence of a rising trend in mesothelioma mortality with increasing radiation exposure, suggests that the mesothelioma (and asbestosis) excess in these workers was due to asbestos exposure in shipyards and power plants and not to occupational low-dose radiation.
Article
Much of the information on the health effects of radiation exposure available to date comes from long-term studies of the atomic bombings in Hiroshima and Nagasaki. Accidental exposures, such as those resulting from the Chernobyl and Kyshtym accidents, have as yet provided little information concerning health effects of ionizing radiation. This paper will present the current state of our knowledge concerning radiation effects, review major large-scale accidental radiation exposures, and discuss information that could be obtained from studies of accidental exposures and the types of studies that are needed.
Article
The main tool in nuclear medicine is ionizing radiation; therefore, it is important for its users to be familiar with its biological effects and pathophysiological basis. Ionization is the process of ion production by ejection of electrons from atoms and molecules after exposure to high temperature, electrical discharges, or electromagnetic and nuclear radiation. Ionizing radiation is subdivided into electromagnetic radiation (X-rays and gamma rays) and particulate radiation including neutrons and charged particles (alpha and beta particles).
Article
Full-text available
The health effects of low-dose radiation (LDR) have been the concern of the academic spheres, regulatory bodies, governments, and the public. Among these effects, the most important is carcinogenesis. In view of the importance of immune surveillance in cancer control, the dose-response relationship of the changes in different cell types of the immune system after whole-body irradiation is analyzed on the basis of systemic data from the author's laboratory in combination with recent reports in the literature. For T lymphocytes J- or inverted J-shaped curves are usually demonstrated after irradiation, while for macrophages dose-response curves of chiefly stimulation with irregular patterns are often observed. The intercellular reactions between the antigen presenting cell (APC) and T lymphocyte (TLC) in the immunologic synapse via expression of surface molecules and secretion of cytokines by the two cell types after different doses of radiation are illustrated. The different pathways of signal transduction thus facilitated in the T lymphocyte by different doses of radiation are analyzed to explain the mechanism of the phenomenon of low-dose stimulation and high-dose suppression of immunity. Experimental and clinical data are cited to show that LDR retards tumor growth, reduces metastasis, increases the efficacy of conventional radiotherapy and chemotherapy as well as alleviates the suppression of immunity due to tumor burden. The incidence of thymic lymphoma after high-dose radiation is lowered by preexposure to low-dose radiation, and its mechanism is supposed to be related to the stimulation of anticancer immunity induced by low-dose radiation. Recent reports on lowering of standardized cancer mortality rate and all cause death rate of cohorts occupationally exposed to low-dose radiation from the US, UK, and Canada are cited.
Article
Full-text available
La materia, i processi di conoscenza e le pratiche sociali vengono considerati in questa tesi come fattori co-emergenti e come riconfigurazioni di boundaries, corpi e pratiche collettive e sociotecniche. Diversi case studies e contributi dagli STS ed altri studi filosofici, antropologici e cognitivi vengono considerati per argomentare sui processi eterogenei di integrazione ed embedding sociale della tecnoscienza nucleare e radiologica nel corso del XX secolo. Matter, knowledge processes and social practices are featured in this thesis as co-emergent factors and reconfigurations of boundaries, bodies and collective enacted practices. Many case studies and contributions by STS as by other philosophical, anthropological and cognitive studies are considered to argue on heterogeneous processes of integration and social embedding of nuclear and radiological technoscience during the XX century.
Article
The prime concern of radiation protection policy since 1959 has been to protect DNA from damage. In 1994 the United Nations Scientific Community on the Effects of Atomic Radiation focused on biosystem response to radiation with its report Adaptive Responses to Radiation of Cells and Organisms. The 1995 National Council on Radiation Protection and Measurements report Principles and Application of Collective Dose in Radiation Protection states that because no human data provides direct support for the linear nonthreshold hypothesis (LNT), confidence in LNT is based on the biophysical concept that the passage of a single charged particle could cause damage to DNA that would result in cancer. Several statistically significant epidemiologic studies contradict the validity of this concept by showing risk decrements, i.e., hormesis, of cancer mortality and mortality from all causes in populations exposed to low-dose radiation. Unrepaired low-dose radiation damage to DNA is negligible compared to metabolic damage. The DNA damage-control biosystem is physiologically operative on both metabolic and radiation damage and effected predominantly by free radicals. The DNA damage-control biosystem is suppressed by high dose and stimulated by low-dose radiation. The hormetic effect of low-dose radiation may be explained by its increase of biosystem efficiency. Improved DNA damage control reduces persistent mis- or unrepaired DNA damage i.e., the number of mutations that accumulate during a lifetime. This progressive accumulation of gene mutations in stem cells is associated with decreasing DNA damage control, aging, and malignancy. Recognition of the positive health effects produced by adaptive responses to low-dose radiation would result in a realistic assessment of the environmental risk of radiation.
Article
An apparent association between radiation exposure and noncancer respiratory diseases (NCRD) in the Life Span Study (LSS) of atomic bomb survivors has been reported, but the biological validity of that observation is uncertain. This study investigated the possibility of radiation causation of noncancer respiratory diseases in detail by examining subtypes of noncancer respiratory diseases, temporal associations, and the potential for misdiagnosis and other confounding factors. A total of 5,515 NCRD diagnoses listed as the underlying cause of death on the death certificate were observed among the 86,611 LSS subjects with estimated weighted absorbed lung doses. Radiation dose-response analyses were conducted using Cox proportional hazard regression analyses for pneumonia/influenza, other acute respiratory infections, chronic obstructive pulmonary disease and asthma. The linear excess relative risks (ERR) per gray (Gy) were 0.17 (95% CI 0.08, 0.27) for all NCRD and 0.20 (CI 0.09, 0.34) for pneumonia/influenza, which accounted for 63% of noncancer respiratory disease deaths. Adjustments for lifestyle and sociodemographic variations had almost no impact on the risk estimates. However, adjustments for indications of cancer and/or cardiovascular disease decreased the risk estimates, with ERR for total noncancer respiratory diseases declined by 35% from 0.17 to 0.11. Although it was impossible to fully adjust for the misdiagnosis of other diseases as noncancer respiratory diseases deaths in this study because of limitations of available data, nevertheless, the associations were reduced or eliminated by the adjustment that could be made. This helps demonstrates that the association between noncancer respiratory diseases and radiation exposure in previous reports could be in part be attributed to coincident cancer and/or cardiovascular diseases.
Article
Purpose of the study A review of epidemiological studies on workers exposed to low doses of ionizing radiation is proposed. Method Workers included are radiologists and radiological technologists, miners, air flight attendants and nuclear industry workers. Studies were listed through medline data base (National Library of Medicine) without restriction on date of publication. Results Radiologists and radiological technologists were among the first to be occupationally exposed to ionizing radiation. Excesses of leukemia, lung and skin cancer were observed for older registration years. For more recent years, epidemiological data lack sufficient statistical power to conclude. Among uranium miners, the lung cancer dose-effect relationship is well established. Effect modifiers have also been observed: decreases in the effect with time since exposure and age at exposure. An increase with the fractionation of dose is also strongly suspected. Excesses of malignant melanomas and breast cancers were observed among airflight attendants. This population is exposed to cosmic radiation, irregular working schedule and frequent jetlags. It is difficult to relate these excesses to these different factors though life-style or reproductive life factors seem to be insufficient to explain excesses of such magnitude. Finally, among nuclear workers, pathologies with more frequent dose-effect relationships are: leukemia except chronic lymphoid leukemia and multiple myeloma, the order of magnitude of excess relative risk being 2 and 4 per Sievert respectively. Lung cancer is also suspected but caution should be taken on potential confusion factors (internal radiation and other occupational factors particularly). Conclusion This review highlights the importance of results obtained from occupational ionising radiation epidemiology. Studies should continue in order to confirm observed dose-effect relationships and better understand some of the excesses observed. It confirms the need for systematic epidemiological surveillance and post-occupational health monitoring of populations concerned.
Article
Risk estimates of fatal cancer constitute the principal component of the health detriment after low doses of ionizing radiation protection recommendations by ICRP and NCRP are based upon them. These risks are presently derived from the Life Span Study of the A bomb survivors in Japan and have recently been supported by a number of relatively imprecise studies of occupational exposure of workers in the U.K., in the U.S., and in Russia. Further verification by more precise studies would be most useful. The most promising future study is that of workers in the U.S. nuclear industry, a study which was proposed some years ago (by New York University) and endorsed by a special committee of the National Academy of Sciences, the National Research Council. The study has not yet been undertaken despite its intrinsic capability to yield more precise results than all other worker studies. This paper describes the present status of background risk estimation for radiation protection and urges that the study of workers in the U.S. nuclear power industry be undertaken without further delay.
Article
We utilize most forms of radiation, the language of nature: our eyes, ears, skin and body utilize light, sound, UV and infrared radiation. In contrast, the effects of low doses of ionizing radiation are not generally understood. Ionizing radiation needs a Rosetta Stone in order to be perceived as a normal, benign agent of our environment. Recent reports showing the benefits of low dose irradiation in cancer mortality raise very important questions about human health. Is ionizing radiation also an essential agent? Exposed nuclear workers had statistically lower cancer mortality rates than unexposed control workers in nuclear plants (p<0.001). Comparison of cancer mortality rates of exposed nuclear workers with those of other workers in the same plants negates any "healthy worker effect" which might be attributed to pre-employment medical screening examinations, better working and socioeconomic conditions, and superior medical care for plant personnel. Those survivors of atomic bombs exposed to low dose irradiation had lower cancer mortality rates than the control cohort. If the sample size were ten times greater this difference would be statistically significant. These results are augmented by the statistically significant inverse relationship between radon in homes and lung cancer mortality. Improved immune competence appears to be the major mechanism which could account for increased fecundity, decreased morbidity from early and mid-life infections, decreased cancer mortality and increased mean life span. A protocol to study natural immunity is outlined. Mice will be maintained at three levels of ionizing radiation: subambient, ambient and suprambient. They will be challenged with serial dilutions of pathogenic bacteria. The results will provide a means to understand the potential benefits of ionizing radiation.
Article
Full-text available
Lung cancer is the most prevalent global cancer, ∼90% of which is caused by cigarette smoking. The LNT hypothesis has been inappropriately applied to estimate lung cancer risk due to ionizing radiation. A threshold of ∼1 Gy for lung cancer has been observed in never smokers. Lung cancer risk among nuclear workers, radiologists and diagnostically exposed patients was typically reduced by ∼40% following exposure to <100 mSv low LET radiation. The consistency and magnitude of reduced lung cancer in nuclear workers and occurrence of reduced lung cancer in exposed non-worker populations could not be explained by the HWE. Ecologic studies of indoor radon showed highly significant reductions in lung cancer risk. A similar reduction in lung cancer was seen in a recent well designed case-control study of indoor radon, indicating that exposure to radon at the EPA action level is associated with a decrease of ∼60% in lung cancer. A cumulative whole-body dose of ∼1 Gy gamma rays is associated with a marked decrease in smoking-induced lung cancer in plutonium workers. Low dose, low LET radiation appears to increase apoptosis mediated removal of α-particle and cigarette smoke transformed pulmonary cells before they can develop into lung cancer.
Article
This paper presents little-known data to support the hypothesis that we need increased background radiation to improve our health. Attention will be drawn to results that demonstrate health benefits of ionizing radiation that have been largely ignored by the news media. Science progresses by interpreting new data not by accepting unfounded assumptions. Arthur Conan Doyle cautioned against making assumptions until one has enough data on which to base the assumption. The International Commission on Radiological Protection failed to follow that advice when it adopted the linear assumption of radiation risk in 1977, primarily to simplify radiation protection regulations. Conan Doyle also pointed out that a premature assumption results in a tendency to interpret data to agree with the assumption. I believe this is one of the reasons the linear assumption has survived for so long. Few radiologists, or other healthcare workers involved with radiation, are aware that billions of their cells are bombarded daily by natural ionizing radiation, much of it from ,9 kBq of natural radioactivity in their bodies. Nearly all the trillions of cells in our body are hit each year, many more than once. Despite this huge amount of radiation damage, cancer is primarily a disease of the elderly. It is reasonable to assume that our very early ancestors solved the problem of cellular repair billions of years ago and that we now have highly efficient repair mechanisms. Cells beyond repair undergo controlled destruction by lysis (apoptosis). According to Cohen (1) if all cancers were curable, longevity would only be increased by about 3 years. It is illogical to suggest that radiation damage to one cell may cause cancer. The probability of one damaged cell causing cancer is infinitesimal - less than ones chance of winning a World lottery if everyone had a ticket. Scientists should not base health effects on assumptions that cannot be proved or disproved. The linear assumption of radiation risk was made to simplify radiation protection regulations. It is unfortunate that many persons have accepted the assump- tion as a scientific truth despite the contradictory evidence of lower cancer mortality in high background areas.
Article
Objective: To examine the risk of diseases among industrial workers with low and fractionated radiation exposures. Method: 372,047 US male shipyard radiation and non-radiation workers were followed for 54 years and compared to US males using Standardized Mortality Ratio (SMR) method. Results: SMRs for both radiation and non-radiation workers had lower risks of death from all causes (0.74; 95% Confidence interval (CI) 0.74-0.75 and 0.77; 95% Cl 0.77-0.78, respectively) and from all cancers (0.92; 95% CI 0.91-0.93 and 0.90; 95% CI 0.89-0.91, respectively) compared to US males. Asbestos-related diseases including pleural cancers, mesothelioma, and asbestosis, but not lung cancers, were statistically higher in both radiation and non-radiation workers compared to the US males. Conclusion: US shipyard male radiation and non-radiation workers did not show any elevated mortality risks that might be associated with radiation exposure.
Article
Full-text available
At its Annual General Meeting in 2004, the Australasian Radiation Protection Society (ARPS) set up a working group to draft a statement of the Society's position on risks from low levels of exposure to ionizing radiation. The resulting position statement was adopted by the Society at its Annual General Meeting in 2005. Its salient features are as follows: • There is insufficient evidence to establish a dose-effect relationship for doses that are less than a few tens of millisieverts in a year. A linear extrapolation from higher dose levels should be assumed only for the purpose of applying regulatory controls. • Estimates of collective dose arising from individual doses that are less than some tens of millisieverts in a year should not be used to predict numbers of fatal cancers. • The risk to an individual of doses significantly less than 100 microsieverts in a year is so small, if it exists at all, that regulatory requirements to control exposure at this level are not warranted.
Article
Full-text available
Controversy continues on whether or not ionizing radiation is harmful at low doses, with unresolved scientific uncertainty about effects below a few tens of millisieverts. To settle what regulatory controls should apply in this dose region, an assumption has to be made relating dose to the possibility of harm or benefit. The position of the Australasian Radiation Protection Society on this matter is set out in a statement adopted by the Society in 2005. Its salient features are: There is insufficient evidence to establish a dose-effect relationship for doses that are less than a few tens of millisieverts in a year. A linear extrapolation from higher dose levels should be assumed only for the purpose of applying regulatory controls. Estimates of collective dose arising from individual doses that are less than some tens of millisieverts in a year should not be used to predict numbers of fatal cancers. The risk to an individual of doses significantly less than 100 microsieverts in a year is so small, if it exists at all, that regulatory requirements to control exposure at this level are not warranted.
ResearchGate has not been able to resolve any references for this publication.