Radiation human exposure

UNSCEAR has globally and extensively surveyed the sources of radiation, human exposure, and the effects of radiation, and the reports have been published successively since 1958. The most recent report was published in 2008. In this chapter, almost all data come from the UNSCEAR reports, especially those published in 1988, 1993, 2000, and 2008. 

Human exposure to radiation is monitored by reporting the absorbed dose and... 

Available information from human exposures indicates that airborne americium-containing particles are deposited in the respiratory tract, cleared to some extent via mucociliary action, and swallowed or expelled (Edvardsson and Lindgren 1976 Fry 1976 Newton et al. 1983 Sanders 1974 Toohey and Essling 1980). Descriptions of human respiratory tract models that can be used for radiation protection also include relevant information regarding biokinetics of inhaled particles (ICRP 1994b, 1995 NCRP 1997). Quantitative data are not available, however. Supporting animal studies include inhalation exposure to aerosols of americium (Buldakov et al. 1972 DOE 1978 Gillett et al. 1985 Sanders and Mahaffey 1983 Talbot et al. 1989 Thomas et al. 1972) or intratracheal instillation of americium compounds (Moushatova et al. 1996). 

Moody JC, Stradling GN, Britcher AR. 1994. Biokinetics of three industrial plutonium nitrate materials Implications for human exposure. Radiat Prot Dosim 53(1-4) 169-172. 

Exposure from terrestrial radionuclides present at trace levels in all soils are specific and relate to the types of rock from which the soils originate. Higher radiation levels are associated with igneous rocks, such as granite, and lower levels with sedimentary rocks. There are exceptions, however, as some shales and phosphate rocks have relatively high contents of radionuclides. Radon and its short-lived decay products in the atmosphere are the most important contributors to human exposure from natural sources. 

X-rays, or gamma rays generated by nuclear decay. Ionizing radiation also includes several types of subatomic particles, such as beta radiation (high-energy electrons) and alpha radiation (helium ions) and others. Medical X-rays are an example of a common beneficial exposure to ionizing radiation. Nuclear radiation is used to generate electricity and cure disease, but is also an important element in military weapons. Uses of nuclear radiation pose serious issues of human exposure and environmental contamination. 

This site contains information on the health effects and regulation of radiation-emitting devices and products. Protecting the public health by providing reasonable assurance of the safety and effectiveness of medical devices and by eliminating unnecessary human exposure to radiation emitted from electronic products. ... 

As long as radiation dose equivalent exposures are low, radiation damage is non-detectable. General effects of short-term radiation exposure are summarized in Table 17.5. The dose equivalents in Table 17.5 are listed in rems. These values are several orders of magnitude greater than what humans received in a year. Annual human exposure... 

Annual human exposure to radiation in millirems (mrems). Note that although radon is radiation from the Earth, it is displayed as a separate category. 

These elements include potassium (found in food) and uranium, thorium, and radon (found in the soil and air). Estimates of cancer incidence from naturally occurring radioisotopes use data on human exposure to the atomic bombs dropped on Japan and to early radiation therapy. 

A brief examination of Thbles 5.1 and 5.2 shows many chemicals that are common in the environment. In contrast to the relatively extensive assessment of human exposure to ionizing radiation, assessment of the extent of human exposures to these and other chemicals is fragmentary. Because there are some 6,000,000 known chemicals (NAS/NRC,... 

Because of the gaps in our present understanding of carcinogenesis and the paucity of human data for most chemicals, risk assessments for chemicals are generally more uncertain than risk assessments for radiation. Tb improve such assessments, there is pai ticular need for further development and validation of methods for extrapolation from animal data to man and further refinement of methods for evaluating variations in hmnan susceptibility and human exposure, e.g., biological markers. 

Guidance on Occupational and Public Exposure Resulting from Diagnostic Nuclear Medicine Procedures Practical Guidance on the Evaluation of Human Exposures to Radiofrequency Radiation... 

McKinlay, A. F., and Diffey, B. L. (1987) A reference action spectrum for ultraviolet induced erythema in human skin, in W. F. Passchier and B. F. M. Bosnajakovic (eds.). Human Exposure to Ultraviolet Radiation Risks and Regulations, Elsevier, New York, pp. 83-87. 

When bone is treated with ionising radiation, free radicals are trapped in the crystal lattice of the bone (Gordy etal., 1955) and consequently can be detected by EPR spectroscopy. Prior to its application for the identification of irradiated food, the technique was used to date archaeological specimens (Ikeya and Miki, 1980) and as an in-vivo dosimeter to determine the level of human exposure to radiation (Pass and Aldrich, 1985). 

O Riordan, M.C., James, A.C. Brown, K. (1982) Some aspects of human exposure to 222Rn decay products. Radiation Protection Dosimetry, 3, 75-82. 

Berry et al. [54] employed guidelines for skin exposure to THz radiation (15 GHz to 115 THz) drawn from American National Standard for the Safe Use of Lasers (ANSI Z136.1) and from the IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields (C95.1). They concluded that the maximum permissible average beam power was 3 mW, suggesting that typical THz imaging systems are safe. 

Some nonionizing radiation sources and their effects on human exposure along with the precautions to be taken in their usage are summarized. 

Ionization radiation is common in our environment. Radiation sources for human exposure include radon, rocks, and soil in some areas, cosmic radiation and medical/... 

Using the Methodic Guides [5] trough an assigned value a, for volumetric activity of / radionuclide in water and a specified human exposure time tj via path j the radiation dose Dij through this path due to water contamination by the indicated nuclide can be calculated via the following formulae ... 

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