Radiation Hormesis in Cancer
T. D. Luckey in Radiation Hormesis, 2020
Radioactive cesium is produced by nuclear blasts and commercial reactors with a 134Cs/137Cs ratio of 0.5. 134Cs has a half life of 2.06 years; 137Cs, 30.2 years. Both isotopes emit weak beta and gamma rays with each decay. The short half life of 134Cs makes its radioactivity of concern in effluents. This was a problem at Chernobyl for several years. Cesium is used commercially, and is proposed for ion propulsion in space vehicles. Cesium in fallout is a hazard from nuclear explosions and is one of the main pollutants from nuclear fuel reprocessing plants. Brucer noted that radioactive cesium was not a problem in normal nuclear power plant operations before instruments became sensitive enough to measure the minute amounts in the environment.118
Radionuclides in water *
Jamie Bartram, Rachel Baum, Peter A. Coclanis, David M. Gute, David Kay, Stéphanie McFadyen, Katherine Pond, William Robertson, Michael J. Rouse in Routledge Handbook of Water and Health, 2015
Cesium-137 is an anthropogenic radionuclide, with a 30 year half-life, produced during nuclear fission (i.e., the splitting of a nucleus into at least two other nuclei) of various isotopes of uranium, plutonium, and thorium. Cesium-137 decays by β decay that is shortly followed by the emission of a γ ray from its short lived decay product, barium-137m (the “m” indicates it is a metastable nuclear isomer that decays very quickly). Two other isotopes of cesium, cesium-135 and cesium-134, are often considered less of a health concern because of their decay characteristics. For example, cesium-135, a β emitter, with a half-life of 2.3 million years has very low specific activity (i.e., number of decays per unit mass or volume). Cesium-134, a β emitter, has a half-life of 2.1 years so does not persist in the environment as long as cesium-137. However, determining cesium-137/cesium-134 ratios may help to identify the source and age of cesium in water.
Biokinetic Models
Shaheen A. Dewji, Nolan E. Hertel in Advanced Radiation Protection Dosimetry, 2019
Cesium is chemically similar to the essential element potassium and is a qualitative physiological analog of K, but important quantitative differences in the biokinetics of K and Cs arise from different rates of transport of these elements across biological membranes. The most important factor affecting the residence time of 137Cs in the body appears to be the mass of K in the body, which is related to the muscle mass and hence the total‑body weight.
Acute and late effects of combined internal and external radiation exposures on the hematopoietic system
Published in International Journal of Radiation Biology, 2019
Laura M. Calvi, Benjamin J. Frisch, Paul D. Kingsley, Anne D. Koniski, Tanzy M. Love, Jacqueline P. Williams, James Palis
The total body irradiation (TBI) dose and volume of injected soluble 137Cs were chosen based on the available literature, with the anticipation of delivering a combined absorbed dose that was sub-lethal across the first 30 days post-exposure (Johnston et al. 2011; Paul et al. 2014), allowing for late hematopoietic niche assessment. Cesium was chosen as the contaminant because of its high level of production from a range of nuclear activities, such as weapons testing, nuclear reprocessing and nuclear fuel cycle discharges, its long half-life, and presence subsequent to multiple nuclear accidents leading to a significant environmental impact (Russell et al. 2015). Since several studies have indicated that soluble cesium is rapidly absorbed and distributed in animal models, irrespective of the route of administration (Furchner et al. 1964; Boecker 1969; Nikula et al. 1995), we therefore chose to administer the soluble form of cesium by intraperitoneal injection. This route allowed us to precisely control the amount of radioisotope delivered and also minimize contamination of laboratory equipment, conforming to our institutional guidelines on the use of radioactivity.
Cs-131 as an experimental tool for the investigation and quantification of the radiotoxicity of intracellular Auger decays in vitro
Published in International Journal of Radiation Biology, 2023
Pil M. Fredericia, Mattia Siragusa, Ulli Köster, Gregory Severin, Torsten Groesser, Mikael Jensen
Using this setup, clonogenic cell survival curves and γH2AX dose effect curves were produced for V79 and HeLa cells. Dose-rate controlled RBE values were calculated for intracellular Cs-131 exposure. The maximum concentration of cesium used was 35 nM (4.6 ng Cs gram of solution), which is less than the typical cesium levels in human tissue (Williams and Leggett 1987) and a cytotoxic effect of cesium can therefore be ruled out. No increase in effectiveness of Cs-131 compared to external γ-rays was observed in HeLa cells for the phosphorylation of histone H2AX (RBE = 1). Nevertheless, from the clonogenic cell survival data, RBE values of 3.2 and 3.9 were found for intracellular Cs-131 decays in V79 and Hela cells, respectively. These RBE results should be seen as preliminary and prove that the experimental setup can be used to study radiation induced biological effects. We have to interpret them with the caveat that the γ-ray exposed V79 cells had 1 or 2 days more time to form colonies than the Cs-131 treated cells and therefore an overestimation of the RBE value cannot be ruled out. The lower RBE value obtained by γH2AX compared to clonogenic cells survival, can be a result of the relatively low expression of H2AX histones (2% of the total H2A histones) in HeLa cells (Bonner et al. 2008). Or it can simply be a result inherent in different methods applied. Indeed, RBE values for high LET radiation, obtained by detection of DNA dsb are often lower than RBE values obtained by other methods (Prise et al. 1998). This has also been observed for Auger emitters (Kriehuber et al. 2004).
The effect of chronic low-dose environmental radiation on organ mass of bank voles in the Chernobyl exclusion zone
Published in International Journal of Radiation Biology, 2020
Kati Kivisaari, Zbyszek Boratyński, Anton Lavrinienko, Jenni Kesäniemi, Philipp Lehmann, Tapio Mappes
Radioactive cesium (Cs137) easily spreads throughout the body due to its water-soluble properties and can be dangerous as both external gamma source as well as internal beta emitter (Nelson et al. 1961). However, the accumulation of Cs137 in different parts of the body in mice varies significantly and after a single dose, excretion reduces the concentration in most organs to fractions of the imbibed dose in mere days (Nelson et al. 1961). Since the bank voles inhabiting the CEZ constantly live in a contaminated environment, their chronic doses are expected to covary with contamination levels within the CEZ (Chesser et al. 2000). The variation in organ masses was assessed across areas with varying levels of ambient radiation, from uncontaminated areas to areas where yearly doses can raise up to 2 Gy/year (habitats where ambient radiation level exceeds 200 µGy/h).
Related Knowledge Centers
- Formate
- Potassium
- Radionuclide
- Solar Cell
- Toxicity
- Pollucite
- Caesium-137
- Nuclear Fission Product
- Emission Spectrum
- Half-Life