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Radiation protection in medicine
Published in Alan Martin, Sam Harbison, Karen Beach, Peter Cole, An Introduction to Radiation Protection, 2018
Alan Martin, Sam Harbison, Karen Beach, Peter Cole
Medical exposure of patients is by far the largest man-made contributor to population dose (>90%) and, in addition, large numbers of medical staff could potentially be exposed to ionizing radiation. Consequently, dose optimization and patient dose-reduction strategies can have a significant effect on the collective dose to society.
Concerns with radiation safety
Published in Yi-Hwa Liu, Albert J. Sinusas, Hybrid Imaging in Cardiovascular Medicine, 2017
Mathew Mercuri, Andrew J. Einstein
Nuclear medicine includes procedures using PET or SPECT systems. Radionuclide myocardial perfusion imaging (MPI) is a common nuclear medicine diagnostic procedure in cardiology. The estimated dose from typical nuclear cardiology procedures range from 2 to >20 mSv, depending on the type of procedure and the radioisotope and protocol used (Einstein et al. 2007; Mettler et al. 2008). For example, a cardiac stress test using 3.5 mCi (129.5 MBq) thallium-201 has an estimated ED of 22 mSv, compared to one using 27.5 mCi (1017.5 MBq) 99mTc-sestamibi where the ED is estimated at 8 mSv (Einstein et al. 2007). Actual patient doses from nuclear medicine procedures vary from estimated doses as a function of individual patient biokinetics and habitus (Mercuri et al. 2012). While nuclear-medicine-based imaging is used less often than radiologic procedures, due to its relatively higher average acute dose, nuclear medicine accounts for a quarter of the collective dose to the U.S. population from medical sources (NCRP 160, 2009).
Radionuclide Concentrations in Water
Published in Michael Pöschl, Leo M. L. Nollet, Radionuclide Concentrations in Food and the Environment, 2006
José Luis Mas, Manuel García-León, Rafael García-Tenorio, Juan Pedro Bolívar
Because of the large amount of this nuclide released to the environment, it has been the target of increasing interest for the scientific community. Concentrations in Baltic fish in the range of 12 to 22 Bq/kg have been reported [86], while Heldal et al. [87] report concentrations 14 Bq/kg for cod in the Irish Sea. It has been shown that the concentration factor increases within the trophic chain, ranging from 10 (lower levels) to 200 (upper levels, sea mammals). The ingestion of fish and shellfish with high 137Cs concentrations can increase the radiological risk for the affected population. As an estimation of that risk, calculations of the corresponding collective doses can be performed; dividing the collective dose by the affected population, the average individual dose can be calculated. For Mediterranean and Black Sea inhabitants, such a collective dose was calculated as 5 man-Sv [85], compared to 1100 man-Sv for naturally occurring 210Pb.
Radiation-induced increases in cancer mortality result from an earlier onset of the disease in mice and atomic bomb survivors
Published in International Journal of Radiation Biology, 2023
However, the somatic mutation theory has an inherent problem in dealing with the concept of a collective effective dose, which aims to describe gross estimation of radiation effects in near future in individuals who are going to be exposed to certain doses of radiation under specific situations. It has been noted that the collective dose should not be used in estimating excess risks that might have occurred in the past (ICRP 2007). Nevertheless, multiplication of quite small doses of radiation (e.g. radiation exposures caused by fallout from atmospheric bomb tests) by a huge number of individuals living on the earth may produce a large number (on the order of a million) of excess cancers cases (ECRR 2010), although this increase is not measurable. The currently presented concept of an earlier onset would help resolving the disputes: specifically, an exposure of a few mGy could lead to a few days or weeks of life lost from cancer when a linear non-threshold dose response is applied (but without taking into account the effect of the dose rate). Obviously, under this scenario, excess number of cancer patients will be close to zero (may not be zero because there might be some types of tumors that are inducible by direct exposures) than estimated previously using the relative risk model.