The Health Effects of Radiation

It should be noted that there is intense controversy as to the health effects of radiation doses below about 100 mSv per year. This estimate of 15,000 annual cancer deaths from indoor radon, as well as estimates of tens of thousands of eventual cancer deaths from Chernobyl exposures, is obtained by applying the linearity hypothesis. This hypothesis has been adopted by most regulatory agencies but is strongly contested by some scientists who believe it overestimates the effects of radiation at low dose levels. Of course, if calculations based on this hypothesis overestimate the deaths from indoor radon, they also overestimate the effects of potential radiation from a waste repository. 

Web site contains presentation material on the health effects of radiation. 

Health Canada - Radiation Protection. Online. Available HTTP (accessed 9 April 2003). Health Canada provides information on the health effects of radiation for consumer and clinical radiation protection. 

Although radiation has found applications in almost all aspects of human activities, most of the ionizing radiation that people are exposed to still comes from natural sources. The health effects of radiation are relatively well understood and can be effectively minimized through careful safety measures and practices. 

The Standards draw upon information derived from extensive research and development work by scientific and engineering organisations, at national and international levels, on the health effects of radiation and techniques for the safe design and operation of radiation sources and upon experience in many countries in the use of radiation and nuclear techniques. The United Nations Scientific Committee of the Effects of Atomic Radiation (UNSCEAR), a body set up by the United Nations in 1955, compiles, assesses and disseminates information on the health effects of radiation and on levels of radiation exposure due to different sources this information was taken into account in developing the Standards. Purely scientific considerations, however, are only part of the basis for decisions on protection and safety, and the Standards implicitly encourage decision-makers to make value judgements about the relative importance of risks of different kinds and about the balancing of risks and benefits. 

Health Effects Of Exposure to Row Revels oflonifing Radiation, Report of Committee on the Biological Effects of Radiation (BEIR Report V), National... 

At first PNL focused on nuclear technology and the environmental and health effects of radiation, but through the years expanded its mission to cover nearly every field of basic science to solve problems in the areas of environment, energy, and national security. Environmental issues and cleanup still encompass two-thirds of PNL work in the 1990s, but PNL has strengthened its role in regional electric power issues as well. 

Epidemiological and Human Dosimetry Studies. Epidemiological studies of radiation dose typically involve estimates of exposure that are based on whole-body measurements of internally-deposited americium. A need remains for epidemiological data that can provide quantitative human dose-response information while supplying additional information on the health effects of exposure to ionizing radiation and americium in particular, for cases of known internal exposure. 

There are several groups of chapters discussing the health effects of radon and its decay products. In Pohl-Ruling et al. (1987) and Reubel et al. (1987), the direct effect of ionizing radiation on cell behavior are presented. Such studies help to elucidate the relationship between the radiation dose and the response at the... 

Goldman, M., An overview of high LET radiation effects in cells, in The Health Effects of Plutonium and Radium (W. S. S. Jee, ed.), pp. 751-766, J. W. Press, Salt Lake City, Utah (1976). 

Both patients and medical staff are understandably concerned about the health effects of exposure to radiation and radioactive contamination. There are two distinct types of radiation exposure, acute and chronic, and two primary exposure modes, radiation and radioactive contamination. Each exposure type and mode is slightly different and must be treated differently by medical staff (see Table 27.2). In addition, there are concerns about the reproductive effects of radiation exposure. In this section, these concerns will be discussed. 

Harley, N.H. (2008). Health effects of radiation and radioactive materials. In Casarett and Doull s Toxicology The Basic Science of Poisons, 7th edition (C.D. Klaassen, ed.), pp. 1053-82. McGraw-Hill Medical, New York. 

Because there are few data on the results of human exposure to actinides, the health effects of these radioelements are more uncertain than those discussed above for ionizing radiation, radon, and fission products. Americium accumulates in bones and will likely cause bone cancer due to its radioactive decay. Animal studies suggest that plutonium will cause effects in the blood, liver, bone, lung, and immune systems. Other potential mechanisms of chemical toxicity and carcinogenicity of the actinides are similar to those of heavy metals and include (i) disruption of transport pathways for nutrients and ions (ii) displacement of essential metals such as Cu, Zn, and Ni ... 

A wealth of new information about radiation exposure over the past decade prompted the revision of the BSS. First and foremost, a study of the biological effects of radiation doses received by the survivors of the atomic bombing of Hiroshima and Nagasaki suggested that exposure to low-level radiation was more likely to cause harm than previously estimated. Other developments—notably the nuclear accident at Three Mile Island in 1979 and that at Chernobyl in 1986, with its unprecedented transboundary contamination—had a profound effect on the public perception of the potential danger from radiation exposure. There were serious accidents with radiation sources used in medicine and industry in Mexico, Brazil, El Salvador and other countries. In addition, more has been discovered about natural radiation—such as household radon—as a cause of concern for health. Finally, natural radiation exposures of workers such as miners, who were not thought of as radiation workers, were discovered to be much higher than had been realised. 

Union. What went wrong in each case How much radiation escaped and entered the surrounding environment What were the health effects of the released radiation ... 

Dose equivalent. Although the biological effects of radiation are dependent upon the absorbed dose, some types of particles produce greater effects than others for the same amount of transferred energy. In order to account for these variations when describing human health risk from radiation exposure, the quantity dose equivalent is used. This is the absorbed dose multiplied by certain quality and modifying factors... 

The randomized controlled trial (RCT) is the de facto standard for studies of the health effects of medical interventions. In these studies, patients are randomized to receive either a therapy to be tested or an alternative (either a placebo or a conventional treatment), and an outcome is measured. RCTs have been used to evaluate therapeutic interventions, including drugs, radiation therapy, and surgical interventions, among others. The measured outcomes vary from hard evidence, such as mortality and morbidity, to softer evidence, such as patient-reported satisfaction and surrogate end points typified by markers of disease activity... 

Akleyev AV, Kossenko MM, Silkina LA, et al. 1995. Health effects of radiation incidents in the southern Urals. Stem Cells 13(Suppl. l) 58-68. 

Green D, Howells G, Humphreys E, et al. 1976. Radiation dose to mouse testes from 239Pu. In Webster S, ed. The health effects of plutonium and radium. Salt Lake City, LIT J.W. Press, 21-31. 

Biological Effects of Ionising Radiation, (BEIR) VI Report The Health Effects of Exposure to Indoor Radon, 1998, US Environmental Protection Agency, Washington DC, USA. 

In light of the biological effects of radiation, it is important to determine whether any levels of exposure are safe. Unfortunately, we are hampered in our attempts to set realistic standards because we do not fully imderstand the effects of long-term exposure. Scientists concerned with setting health standards have used the hjrpothesis that the effects of radiation are proportional to exposure. Any amount of radiation is assumed to cause some finite risk of injury, and the effects of high dosage rates are extrapolated to those of lower ones. Other scientists believe, however, that there is a threshold below which there are no radiation risks. Until scientific evidence enables us to settle the matter with some confidence, it is safer to assume that even low levels of radiation present some danger. 

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