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The Poisoned Chalice
Published in Alan Perkins, Life and Death Rays, 2021
Tritium is a radionuclide of hydrogen with a physical half-life of 12.3 years. It decays to helium giving off beta radiation (electrons). It does not pose an external danger to biological tissue as the beta particles cannot travel very far; however, when inhaled or ingested, it can result in internal poisoning. Intake can occur by swallowing, inhalation and via skin puncture or through open wounds. Absorption through the gastrointestinal tract normally takes place within a few minutes and is complete within 45 minutes. Once tritium enters the bloodstream, it quickly disperses and is uniformly distributed throughout the water spaces of soft tissues. It is one of the less radiotoxic radionuclides, and following poisoning incidents it can be readily flushed from the body by increasing water consumption. Tritium is commonly used in civilian and military nuclear power plants and has been observed to be discharged into the environment in relatively large quantities.
Radiation Hormesis in Cancer
Published in T. D. Luckey, Radiation Hormesis, 2020
Tritium has many uses in biochemical research and medicine. Although its physical and chemical properties resemble those of hydrogen, it can be differentiated from hydrogen in certain metabolic reactions. Following any mode of intake, 3H becomes uniformally distributed throughout the body. 3H is one of the least carcinogenic of all radionuclides.791 It normally provides about 0.01 μSv/year in mammals.
The Liquid Scintillation Counting Process. The Gamma Counting Process
Published in Howard J. Glenn, Lelio G. Colombetti, Biologic Applications of Radiotracers, 2019
where n = neutron, p+ = proton, e− = electron, e+ = positron, = antineutrino, and v = neutrino. Our interest is largely in Equation 1. Tritium, whose nucleus is composed of one proton and two neutrons, decays by the conversion of one of its two neutrons to a proton with the ejection of an electron. The tritium nucleus then becomes, as a result of beta decay, a nucleus having two protons and a single neutron, that of stable helium. Carbon-14, whose nucleus is composed of 6 protons and 8 neutrons, becomes, as a result of beta decay, the stable element nitrogen, whose nucleus has 7 protons and 7 neutrons. Similar transformations occur with other beta emitters. The total energy of beta decay consists of the energy of the emitted beta particle (electron) plus the energy of the antineutrino. This energy is called Emax. Only a few of the emitted beta particles have this maximum energy. As shown in Figure 1, a spectrum of energy for the beta particles results whereby the most numerous of the emitted particles have an energy of approximately one-third that of Emax. Emax for tritium is only 0.0181 MeV; that of 14C is only 0.156 MeV. Since much of this low beta emission energy can be easily absorbed by the compound itself, by its surroundings, or by necessary covers on gamma detecting equipment, the technique of liquid scintillation counting developed. Without this technique, radiobiology, as we know it today, would not be possible.
Prolonged effect associated with inflammatory response observed after exposure to low dose of tritium β-rays
Published in International Journal of Radiation Biology, 2020
Yi Quan, Zhaoyi Tan, Yang Yang, Bing Deng, Long Mu
With the development of nuclear technology, nuclear fusion and related technologies play a remarkable role in the ongoing provision of green energy resources (Editorial 2016). As the only radioactive isotope of hydrogen and main fuel of fusion reactor, tritium production and processing capacity will be unprecedented. To explore the hazardous impact of tritium, abundant studies have been performed on radiobiological effects induced by tritium. Based on these data, individual dose limit from tritium exposure has been established by the International Commission on Radiological Protection (ICRP). A radiation weighting factor of 1 for tritium exposure is commonly used, although the value of relative biological effectiveness (RBE) significantly elevates and varies from 1.1 to 5.0 in the situation of chronic exposure with γ-rays as a reference ray (Little and Lambert 2008). In addition, various national standards of tritium concentration in drinking water are used and vary from 100 Bq/L to 76 kBq/L (Guéguen et al. 2018). It reflects there is a lack of sufficient knowledge to recognize the evolution of biological damage produced by tritium exposure and its subsequent evaluation of health risk (Kocher and Hoffman 2011).
Radiobiological effects of tritiated water short-term exposure on V79 clonogenic cell survival
Published in International Journal of Radiation Biology, 2018
Mattia Siragusa, Pil M. Fredericia, Mikael Jensen, Torsten Groesser
Tritium (3H) is a radioactive isotope of hydrogen and decays solely by β− decay to 3He through emission of an electron (β–ray) with a well-known spectral distribution and a maximum energy of 18.6 keV. The co-emitted electron antineutrino can be safely disregarded in this dosimetric context. The range of the tritium beta electrons at 18.6 keV is approximately 6 μm in water (Carsten 1979), which is fairly short when compared to the average size of a mammalian cell diameter (approximately 10–20 μm). Its characteristics are well described in the literature and summarized in Table 1. Tritium has a half-life of 12.33 years and has both natural origins (cosmic ray interactions with the atmosphere) and artificial sources (reactors and accelerators, nuclear weapons testing). It is present in the human environment and deserves some attention for radiation protection reasons, especially as it has a rapid biological distribution both as tritiated water (HTO) and as organic bound tritium. The release of HTO from nuclear power plants into the underground and eventually drinking water is considered a common source of radiation exposure to the general public (Carsten 1979; Vri and Binet 1984; Le Guen 2009).
COHERE – strengthening cooperation within the Canadian government on radiation research
Published in International Journal of Radiation Biology, 2021
Vinita Chauhan, Julie Leblanc, Baki Sadi, Julie Burtt, Kiza Sauvé, Rachel Lane, Kristi Randhawa, Ruth Wilkins, Debora Quayle
Tritium exposure can pose a health risk if ingested through drinking water or food, or if inhaled or absorbed through the skin in large quantities. Issues raised in Canada include handling, control, and releases of tritium, tritium drinking water limits, tritium’s fate in the environment, and the health effects of tritium exposure (Canadian Nuclear Safety Commission 2010; Bundy 2012). The CNSC conducted research to address these concerns and increased our scientific understanding of tritium. Tritium research questions of interest include the mechanistic and biokinetic nature of HTO (tritiated water) and OBT (organically bound tritium) ingested and incorporated in different forms.