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A Series of Unfortunate Events
Published in Alan Perkins, Life and Death Rays, 2021
The total release of radioactive substances was considered to be greater than 14 exabecquerels (EBq, 14 × 1018 Bq), which included 1.8 EBq of iodine-131, 0.085 EBq of caesium-137 and other caesium radionuclides, 0.01EBq of strontium-90 and 0.003 EBq of plutonium radionuclides. The dispersal of iodine-131 presented an immediate problem to the local population. All 45,000 residents of the power plant town of Pripyat were evacuated on April 27. By May 14, around 116,000 people who had been living within a 30-kilometre radius had been evacuated and relocated. About 1,000 of these residents returned unofficially to live in the contaminated zone preferring to live in their own homes despite the health risks. Most of those evacuated individuals received radiation doses of less than 50 mSv, although a few received 100 mSv or more. Large areas of Europe were affected and an area of more than 200,000 square kilometres was contaminated with caesium-137. The three most affected countries were Belarus, the Russian Federation and Ukraine, but the contamination affected countries throughout Europe. After the initial period, caesium-137 became the nuclide of greatest radiological importance. Ground deposition was strongly influenced by the prevailing winds and rainfall, but the end result was that sheep in highland areas as far away as Wales had consumed grass contaminated with caesium-137 and farmers were prohibited from selling their lamb at food markets for many weeks after the incident.
Dose Coefficients
Published in Shaheen A. Dewji, Nolan E. Hertel, Advanced Radiation Protection Dosimetry, 2019
Nolan E. Hertel, Derek Jokisch
Due to its valence electron structure, cesium exhibits biochemistry similar to potassium. Due to the body’s widespread use of potassium, cesium tends to accumulate in a variety of tissues but will favor skeletal muscle, as shown in Figure 8.27 (ICRP 2017). Cesium-137’s progeny is barium-137m whose half-life (2.25 min) is short, but long enough to allow for migration out of the tissue it is created in and back to the bloodstream. Given the distribution of muscle throughout the body, and the long-range nature of 137mBa’s 661.6 keV gamma ray, the dose to tissues ends up more uniformly distributed than the other examples in this chapter, as seen in Figure 8.28 .
Outdoor Emissions
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
About 20%–40% of all core caesium-137 was released, containing 85 PBq in all.490,491 Cadmium was released in aerosol form; caesium-137 along with isotopes of strontium, are the two primary elements preventing the Chernobyl exclusion zone being reinhabited.492 The caesium-137 activity represented by 8.5 × 1016 Bq would be produced by 24 kg of caesium-137.107 Cs-137 has a half-life of 30 years.490
Effects of gamma irradiation on morphology and protein differential in M1V1 population of Vanilla planifolia Andrews
Published in International Journal of Radiation Biology, 2023
Rohayu Ma’Arup, Nur Syazwani Ali, Fisal Ahmad, Zaiton Ahmad, Mohamad Feisal Mohamed Norawi, Homaa Faezah Moinuddin
The investigations were carried out at the main campus nursery of University Malaysia Terengganu, Kuala Nerus in December 2019. Thirty cuttings of Vanilla planifolia (100 cm length) from Amani Vanilla Temerloh, Pahang were irradiated using Biobeam GM 8000 at the Division of Agrotechnology and Biosciences, Malaysian Nuclear Agency, Bangi. The source of gamma radiation was Caesium-137. Each dose of gamma (γ) radiation (0, 10, 30, 40, and 50 Gy) has five replicates of vanilla cuttings that were cultivated in a pot containing a soil mixture. The soil ratio was 4 (topsoil): 1(sand): 4 (cocopeat and charcoal to improve drainage and retained moisture of the soil) were used in this experiments. The pots were arranged in Complete Randomized Design (CRD) as an experimental design and cultivated under a 70% mesh black net. The manual irrigation system is used (once a day) with full capacity. Two types of fertilizer were used; goat manure (5 kg ha−1) and effective microbes (EM, foliar fertilizer). All the standard cultural operations were followed.
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.