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Thallium Imaging in the Evaluation of Breast Malignancies
Published in Raymond Taillefer, Iraj Khalkhali, Alan D. Waxman, Hans J. Biersack, Radionuclide Imaging of the Breast, 2021
Lebowitz et al. [7] implied that Tl-201 would merit evaluation for myocardial visualization as well as tumor imaging because of its physiologic and biologic properties, which were similar to potassium. This group suggested that because of the similarity of thallium to alkaline metals such as cesium, which has previously been shown concentrate in tumors, the use of radiothallium should also be evaluated for this application.
Our Radiation Environment
Published in T. D. Luckey, Radiation Hormesis, 2020
Atomic blasts have released about 13 GBq of 3H in the northern hemisphere, Atmospheric atomic bomb tests release little more 131I than explosions of nuclear power reactors (Table 1.11).252Induced and fission products with half lives longer than two months are 55Fe, 90Sr, 106Ru, 137Cs, 144Ce, and 147Pm. Of these, cerium contributes the most radiation for one to three years, then cesium and strontium produce the dominant beta rays from fallout. The health hazards from ingestion of strontium and cesium are well documented.252 Almost 740 PBq of 90Sr were produced in atmospheric atom bomb testing from 1952 to 1962.252 Little more was added following the atmospheric test ban. Much of this strontium fell to earth and entered the food chain. The production of 137Cs in fallout is the limiting factor in atomic blasting for commercial purposes. The release of 134Cs from Chernobyl exceeded that from atomic bombs. The 14C released by atomic bombs has received little attention because its long half life effectively prevents any readily observed physiologic effect. Although no alpha emitters are produced in atmospheric atomic tests, residual 235U and 239Pu occur in the dust. The 3 to 4 tons of plutonium released during the atmospheric nuclear bomb tests from 1945 to 1965 are reflected in human tissues (Table 1.8b) and dispel the popular statement that, “One ton of plutonium is enough to kill every person on earth.”
Miscellaneous Radiotracers for Imaging
Published in Garimella V. S. Rayudu, Lelio G. Colombetti, Radiotracers for Medical Applications, 2019
Gopal B. Saha, Charles M. Boyd
Cesium-129 has a half-life of 32.9 hr and decays to 129Xe 100% by electron capture.1 It emits principal y-radiations of 375 keV (48%) and 416 keV (25%).1 The former photons are reasonably useful for scintillation camera studies; the latter would, however, require improved shielding over high-energy collimators.
Oral formulation of Prussian blue with improved efficacy for prophylactic use against thallium
Published in Drug Development and Industrial Pharmacy, 2023
Nidhi Sandal, Vivek Kumar, Pooja Sharma, Mahendra Yadav
The binding efficiency of PB depends on concentration, pH, exposure time, particle size, moisture content, storage conditions, etc. The factor emphasized here is the effect of pH. Thus a formulation comprising PB and an antacid was developed. The formulations were characterized for its pharmaceutical parameters and compared with the commercially available capsules Radiogardase®-Cs. In vitro and in vivo pharmacokinetic studies for removal of cesium and Tl were performed to study the efficacy of optimized formulation for prophylactic use in comparison to Radiogardase®-Cs. The results of in vitro and in vivo Tl binding studies showed that FF1–FF4 formulations were more efficacious than Radiogardase®-Cs in simulated gastric fluid/stomach. FF4 blocked the absorption of Cs/Tl from the stomach. So, the formulation FF4 can be used prophylactically for blocking the absorption of radioactive or non-radioactive cesium and Tl from stomach. The FF4 formulation can be recommended for use in rescue responders as one time use medicine.
A review of the impact on the ecosystem after ionizing irradiation: wildlife population
Published in International Journal of Radiation Biology, 2022
Georgetta Cannon, Juliann G. Kiang
Twenty-one years later after the Chernobyl power plant explosion, various isotopes of plutonium, strontium-90, americium-241, and cesium-137 were still detected at high levels causing adverse biological effects across the nearby areas (Voitsekhovych et al. 2007). Wildlife continued to be exposed to substantial radiation doses after humans were evacuated from these areas. The half-life of cesium-137 is approximately 30 years and it decays by β emission to a metastable isomer of barium-137. The half-life of barium-137 isomer is 2 minutes. Subsequently, the metastable isomer emits γ radiation and becomes ground state barium (Baum et al. 2002). Food or water contaminated with cesium-137 that are ingested lead to internal β and γ radiation doses in addition to external radiation doses. The half-life of cesium-134 is about 2 years. Cesium-134 emits β particles. The half-life of strontium-90 is approximately 29 years. Strontium-90 emits pure β radiation. Most of the plutonium isotopes emit α particles, which are ionizing and harmful, but have a short penetration distance. The half-life of plutonium-241 is approximately 14 years. It emits β radiation to become americium-241. The half-life of americium-241 is 432 years, and it emits α particles to become neptunium-237, with a by-product of γ emissions (Baum et al. 2002). This is the composition of radiation released and retained in the soil, water and air across the Chernobyl landscape. In addition to external radiation exposure, ingestion of contaminated food and water by wildlife occurred from the beginning of the disaster and continues to the present.
Consequences of a large-scale nuclear accident and guidelines for evacuation: a cost-effectiveness analysis
Published in International Journal of Radiation Biology, 2020
Moshe Yanovskiy, Ori Nissim Levi, Yair Y. Shaki, Yehoshua Socol
Radiation contamination decreases with time due to radioactive decay. In case of NPP accident, many radionuclides are released. The longest-living relevant radionuclide—cesium-137 (Cs-137)—has a half-life of 30 years; thus, its radioactivity decreases rather slowly: 50% of the initial level after 30 years, 25% of the initial level after 60 years and so on. However, many short-living isotopes are also released, so the initial radiation level decreases rather rapidly during the first year. There is also another mechanism of radiation rate decrease—the migration of radionuclides from the contaminated surface due to rain, wind, road traffic etc. The data for Chernobyl and Fukushima is fairly consistent (Balonov 2016; IRSN 2016; Zoriy et al. 2016; WNA 2018b) and shown in Figure 1. As a result, radiation dose absorbed in 10 years is only twice higher than the first-year dose, and the lifetime dose is approximately equal to three first-year doses (UNSCEAR 2013, p. 209). Although this fact is well known, it is not always considered in the radiation-protection context. One year after the accident and onwards the dose-rate R(t) can be approximately described by R(t) = R(0)/(1 + 0.75 × t) where t – time in years. This approximation is illustrated in Figure 1. Table 1 summarizes doses absorbed during different periods of time after the accident relative to the dose absorbed during the first 12 months.