Radiation Injury

Since the development of x-rays in the late 19th century, radiation has increasingly been used for diagnostic imaging and various industrial purposes. The human health consequences of radiation exposure can range from minor asymptomatic exposures to the development of potentially fatal acute radiation sickness depending on the characteristics of the exposure. This review provides an overview of radiation injury, including historical perspective and principles of toxicity; assessment and stabilization (bedside evaluation, supportive care, and empirical therapy); diagnosis (estimation of radiation dose, laboratory assessment, biodosimetry and bioassays, smoke inhalation, and psychiatric sequelae); treatment and disposition (hematologic acute radiation illness, countermeasures and antidotes, gastrointestinal symptoms, fluid and electrolyte management, surgical intervention, local radiation injury, psychiatric treatment, radiation exposure during pregnancy, palliative care, and disposition); and outcomes (carcinogenesis, noncancer effects). Tables include the characteristic of common radioactive isotopes, common radiation dose equations and conversions, prescribing information for colony-stimulating factors, recommended antimicrobial prophylaxis and treatment regimens, and radioisotope decorporation or blocking agents. Figures show types of ionizing radiation, comparison of radiation contamination and exposure, patterns of early lymphocyte response based on radiation dose, the relationship between time to onset of vomiting and radiation dose, and a sample body chart for documentation of radiation contamination. This review contains 5 figures, 5 tables, and 82 references. Key Words: radiation, radiation exposure, radiation sickness, diagnostic imaging, pregnancy, carcinogenesis, toxicity, acute radiation syndrome (ARS)

Radiocesium levels in contaminated forests has remained stable, even after heavy rains due to typhoons and localized downpours

In recent years, Japan has suffered serious damage due to natural disasters such as earthquakes, heavy rains due to tropical storms (typhoons) and localized downpours. To assess the chronological changes in the attenuation of external exposure doses and environmental radiation contamination due to the rainfall associated with typhoons and heavy rains during October to December 2019 in Fukushima, we measured environmental radiation levels in forest areas along the Mt Okura hiking trail in Tomioka Town, Fukushima Prefecture, near the Fukushima Daiichi Nuclear Power Station. We confirmed that (1) current ambient dose rates of 0.38–0.95 μSv/h in most forest areas were 79.9–84.7% higher than in residential areas; (2) the number of sites along the hiking trail where 137Cs was detected was limited (1.1–4.7%); and (3) individual dose rates of 0.21–0.34 μSv/h were lower than ambient dose rates. These findings suggest that radiocesium has remained stable in natural forests that have not been decontaminated even though current levels are low, despite the occurrence of heavy rainfall associated with Super Typhoon Hagibis in 2019 and localized downpours. Hiking while managing exposure to environmental contamination using a personal dosimeter may be the safest model for spending time of leisure activities.

Analysis of radiouclide contamination of forestry products on the territory of Ukraine 2013–2019

The analysis of the results of radiological studies of food and feed conducted by the specialists of the state laboratories of the State Consumer Service for 2013–2019 is performed. The analyzed results show that in the territories assigned to the radiation contamination zones, samples with a radionuclide content exceeding the maximum admissible levels of 137Cs and 90Sr are constantly detected. Even 33 years after the Chernobyl accident, the specific activity of 137Cs in mushrooms and berries remains high. Specialists of the state laboratories of the State Consumer Service during this period carried out radiological examinations of food and feed for the contents of 137Cs and 90Sr. Exceedance of the maximum permissible levels (DR) of 137Cs was detected in 3.253 samples, of which 1.277 were fresh mushrooms and yagi and 729 were dried and dried mushrooms and berries. It is established that forest mushrooms and berries (fresh and dried) are the critical dose-forming foods, accounting for the largest proportion of about 62 % of the total positive samples. A much better situation was observed in detecting an excess of DR 90Sr. During the study period, contamination of 90Sr food and feed is of a single nature. The dynamics of detecting excesses of DR 137Cs in forest mushrooms and berries (fresh and dried) for 2013–2019 have significant fluctuations related to environmental conditions and the multidirectional migration of man-made radionuclides in forest ecosystems. The use, even in small quantities, of forest origin products with a maximum specific activity of 137Cs can play a significant role in the internal exposure of long-lived radionuclide to the local population. Therefore, the largest proportion of forest food products (62 %) is in the balance of radionuclide-contaminated products during the last seven years. (2013–2019) and other products and feeds are the basis for further radiological control by their state laboratories of the State Consumer Service.

Evaluating the radiation contamination dose around a high dose per pulse intraoperative radiotherapy accelerator: a Monte Carlo study

Aim:In this study, the radiation contamination dose (RCD) for different combinations of electron energy/distance, applicator and radius around the light intraoperative accelerator (LIAC), a high dose per pulse dedicated intraoperative electron radiotherapy machine, has been estimated. Being aware about the amount of RCDs is highly recommended for linear medical electron accelerators.Methods and methods:Monte Carlo Nuclear Particles (MCNP) code was used to simulate the LIAC® head and calculate RCDs. Experimental RCDs measurements were also done by Advanced Markus chamber inside a MP3-XS water phantom. Relative differences of simulations and measurements were calculated.Result:RCD reduction by distance from the machine follows the inverse-square law, as expected. The RCD was decreased by increasing angle from applicator walls opposed to the electron beam direction. The maximum differences between the simulation and measurement results were lower than 3%.Conclusions:The RCD is strongly dependent on electron beam energy, applicator size and distance from the accelerator head. Agreement between the MCNP results and ionometric dosimetry confirms the applicability of this simulation code in modelling the intraoperative electron beam and obtaining the dosimetric parameters. The RCD is a parameter that would restrict working with LIAC in an unshielded operative room.

Infection Load and Prevalence of Novel Viruses Identified from the Bank Vole Do Not Associate with Exposure to Environmental Radioactivity

Bank voles (Myodes glareolus) are host to many zoonotic viruses. As bank voles inhabiting areas contaminated by radionuclides show signs of immunosuppression, resistance to apoptosis, and elevated DNA repair activity, we predicted an association between virome composition and exposure to radionuclides. To test this hypothesis, we studied the bank vole virome in samples of plasma derived from animals inhabiting areas of Ukraine (contaminated areas surrounding the former nuclear power plant at Chernobyl, and uncontaminated areas close to Kyiv) that differed in level of environmental radiation contamination. We discovered four strains of hepacivirus and four new virus sequences: two adeno-associated viruses, an arterivirus, and a mosavirus. However, viral prevalence and viral load, and the ability to cause a systemic infection, was not dependent on the level of environmental radiation.