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Application of dual energy X-ray absorptiometry
Published in R. C. Richard Davison, Paul M. Smith, James Hopker, Michael J. Price, Florentina Hettinga, Garry Tew, Lindsay Bottoms, Sport and Exercise Physiology Testing Guidelines: Volume II – Exercise and Clinical Testing, 2022
DXA involves a small amount of ionising radiation. The effective dose to an adult from a typical bone density scan is around 7 μSv depending on the manufacturer, model and scan mode used. The total body scan brings a lower effective dose of around 3.0 μSv. It is useful to compare these values to the natural background radiation dose in the UK, which is approximately 7.3 μSv daily (2.7 mSv annually) (Public Health England, 2011). For example, a standard mode total-body scan would give an exposure that is less than one day of natural background radiation. Although the dose of radiation from DXA is small, all laboratories or centres performing DXA scans must follow the regulations set out in the Ionising Radiation Regulations 2017 (IRR17) (Health and Safety Executive, 2018) and the Ionising Radiation for Medical Exposure Regulations (IRMER) (Department of Health and Social Care, 2018), and all operators must have received IRMER-specific training. DXA scans performed for human participant research, with accompanying ethical approval from an NHS Research Ethics Committee where the input from a medical imaging expert and a clinical radiation expert are required.
Application of dual energy x-ray absorptiometry
Published in R. C. Richard Davison, Paul M. Smith, James Hopker, Michael J. Price, Florentina Hettinga, Garry Tew, Lindsay Bottoms, Sport and Exercise Physiology Testing Guidelines: Volume I – Sport Testing, 2022
DXA involves a small amount of ionising radiation. The effective dose to an adult from a typical bone density scan is around 7 µSv depending on the manufacturer, model and scan mode used. The total body scan brings a lower effective dose of around 3.0 µSv. It is useful to compare these values to the natural background radiation dose in the UK, which is approximately 7.3 µSv daily (2.7 mSv annually) (Public Health England, 2011). For example, a standard-mode total body scan would give an exposure that is less than 1 day of natural background radiation. Although the dose of radiation from DXA is small, all laboratories or centres performing DXA scans must follow the regulations set out in the Ionising Radiation Regulations 2017 (IRR17) (Health and Safety Executive, 2018) and the Ionising Radiation for Medical Exposure Regulations (IRMER) (Department of Health and Social Care, 2018), and all operators must have received IRMER-specific training. DXA scans performed for human participant research must have accompanying ethical approval from a National Health Research (NHS) Research Ethics Committee, where the input from a medical imaging expert and a clinical radiation expert is required.
Theoretical Background to Radiation Protection
Published in W. P. M. Mayles, A. E. Nahum, J.-C. Rosenwald, Handbook of Radiotherapy Physics, 2021
Mike Rosenbloom, W. P. M. Mayles
The exponential attenuation of x- and γ-rays in passing through protective barriers means that it is impossible to completely eliminate exposure of staff and the public arising from the use of ionising radiation in medicine, and they will in any case be exposed to natural background radiation. Natural background radiation is responsible for a worldwide average dose of 2.4 mSv per year, of which 1.2 mSv is due to radon and its daughter products (Thorne 2003). The risk associated with the genetic effects of radiation is smaller than the risk of induction of cancer (UNSCEAR 2001), so it is the latter that is the principal consideration in determining dose limits. It is also important to ensure that the costs of reducing exposure to a given level are commensurate with the benefits (i.e. reduction in the excess incidence of cancer) so obtained. This cost–benefit comparison cannot be made without knowledge of the risk of developing cancer as a function of exposure.
Main radiation pathways in the landscape of Armenia
Published in International Journal of Radiation Biology, 2023
V. B. Arakelyan, G. E. Khachatryan, A. G. Nalbandyan-Schwarz, C. E. Mothersill, C. B. Seymour, V. L. Korogodina
Armenia is a country of diverse mountainous landscapes (Figure 1). Natural background radiation comes mainly from rocks and cosmic rays. An additional source of high-energy electrons and gamma quanta are the most powerful natural electron accelerators operating in a highly electrified atmosphere during frequent thunderstorms in the Mount Aragats (Chilingarian et al. 2021), which increase the concentration of Rn-222 and its daughter products in the atmosphere (Chilingarian, Hovsepyan, Sargsyan 2020; Chilingarian, Hovsepyan, Karapetyan, et al. 2020). Atmospheric radiation is random and increases in the mountains. The radiation emanating from rocks has a constant activity, depending on the location. The highest activity corresponds to the mining centers of Kajaran and Kapan (Davtyan and Ananyan 1963; Belyaeva et al. 2019), and Yerevan city (Nalbandyan 2005; Belyaeva et al. 2021) (Figure 2). Radionuclides, mainly K-40, migrate with mountain rivers (Araks and Kura basin) to the valleys (Saghatelyan and Nalbandyan 2007). Their path depends on the climate and soils of the area (Figure 4(a,b)), and ends in the bottom sediments of the river or lakes, in soils and plants.
Assessment of probable scenarios of radiological emergency and their consequences
Published in International Journal of Radiation Biology, 2020
Yehoshua Socol, Yuriy Gofman, Moshe Yanovskiy, Binyamin Brosh
The cost of the clean-up strongly depends on the target value of residual radioactivity. Actually, the dependence is nonlinear since it is much more expensive to perform the advanced stages of the decontamination. Since such dependence of the cost on the target is nonlinear and case-specific, we do not provide quantitative recommendations for setting targets for decontamination efforts. Nevertheless, we would like to stress the following important fact for setting the target value: The buildings provide considerable radiation protection. Different building types provide different values of radiation dose reduction (protection factor PF), varying from PF = 2 for 1-story wood frames to PF = 50 and higher for middle-level apartments of multi-story buildings (HSC 2010). For urban environments (multi-story buildings), the effective dose received by people is only 10–20% of the dose measured in the open air (UNSCEAR 2000, Table 30, p. 581). For example, an open-air dose of 500 mSv per year (about 60 µSv/h, or 20-fold the world-average natural background radiation) corresponds to an effective dose of up to 100 mSv/year.
IL-2 and IL-2R gene polymorphisms and immune function in people residing in areas with high background radiation, Yangjiang, China
Published in International Journal of Radiation Biology, 2020
Wen Cuiju, Su Shibiao, Tang Ying, Li Rongzong, Xu Haijuan, Chen Huifeng, Wang Tianjian
Areas with a high natural background radiation are ideal for studies focusing on low dose radiation exposure, allowing for the fundamental epidemiologic investigation of human diseases like cancer, eye disease, cardiovascular disease, and oxidative stress (Tharmalingam et al. 2017; United Nation 2017; Tang and Loganovsky 2018). This is the first study to focus on IL-2 and IL-2R polymorphisms in humans with HNBR exposure. In this study, the serum levels of IL-2 and IL-5 were higher, and those of TGFβ were lower in the HNBR group than the CA group, indicating that long-term low dose radiation exposure may induce immunity stimulation. Additionally, we found that the levels of IL-2 and IL-2RB mRNA expression increased, while those of IL-2RG mRNA expression decreased. These observations suggest the IL-2 and IL-2R subunits may be involved in the stimulation of immune activity by low dose radiation exposure. Moreover, we investigated the differences in the IL-2 and IL-2R subunit gene polymorphisms between the HNBR and CA groups. Of the selected 10 SNPs, rs76206423 showed an association with long-term exposure to low dose radiation. It is known that rs76206423 is located in the IL-2RB gene, which is the upstream variant involved in IL-2RB expression. Thus, our study is in agreement with those suggesting that low dose radiation exposure leads to enhanced immunity, and IL-2 and IL-2R polymorphism should be considered involved in the mechanism of regulating immunity.