The Improvement of the Regional Regulatory Governance System for Radiation Risk Management: Spatial Analysis on Radiation Hazards in South Korea

Since the 2011 Fukushima nuclear power plant accident, nuclear regulators have strengthened safety standards or decided to decommission the nuclear power plant. The vast majority of radiation is from nuclear power plants, so safety measures are also concentrated in nuclear power plants. Radioactive materials located much closer to the people are scattered around the nation. However, it is difficult for citizens to predict the radiation risk around them because regulatory agencies do not provide adequate information on radiation. The main goal of this study is to analyze the spatial distribution patterns of radioactive materials that serve as indicators for potential risk from a radiological hazard. The empirical findings in this study demonstrate the presence of spatial autocorrelation for the number of radiation licenses among 244 regions in the Republic of Korea. The policy implications are three-fold: (1) it is necessary to improve regulatory governance in consideration of permitted use; (2) the regional offices of regulatory agency can be established based on the identified spatial distribution of permitted use; (3) it is required to improve the information-disclosure system for materials. This study provides an opportunity to create a safer society by understanding the radiation around the public in general.

Dose-dependent Transmissibility of Chromosome Aberrations at First Mitosis after Exposure to Gamma Rays. I. Modeling and Implications Related to Risk Assessment

The relationship between certain chromosomal aberration (CA) types and cell lethality is well established. On that basis we used multi-fluor in situ hybridization (mFISH) to tally the number of mitotic human lymphocytes exposed to graded doses of gamma rays that carried either lethal or nonlethal CA types. Despite the fact that a number of nonlethal complex exchanges were observed, the cells containing them were seldom deemed viable, due to coincident lethal chromosome damage. We considered two model variants for describing the dose responses. The first assumes independent linear-quadratic (LQ) dose response shapes for the yields of both lethal and nonlethal CAs. The second (simplified) variant assumes that the mean number of nonlethal CAs per cell is proportional to the mean number of lethal CAs per cell, meaning that the shapes and magnitudes of both aberration types differ only by a multiplicative proportionality constant. Using these models allowed us to assemble dose response curves for the frequency of aberration-bearing cells that would be expected to survive. This took the form of a joint probability distribution for cells containing ≥1 nonlethal CAs but having zero lethal CAs. The simplified second model variant turned out to be marginally better supported than the first, and the joint probability distribution based on this model yielded a crescent-shaped dose response reminiscent of those observed for mutagenesis and transformation for cells “at risk” (i.e. not corrected for survival). Among the implications of these findings is the suggestion that similarly shaped curves form the basis for deriving metrics associated with radiation risk models.

Ten Good Reasons to Practice Neuroultrasound in Critical Care Setting

In the beginning, cerebral ultrasound (US) was not considered feasible because the intact skull was a seemingly impenetrable obstacle. For this reason, obtaining a clear image resolution had been a challenge since the first use of neuroultrasound (NUS) for the assessment of small deep brain structures. However, the improvements in transducer technologies and advances in signal processing have refined the image resolution, and the role of NUS has evolved as an imaging modality for the brain parenchyma within multiple pathologies. This article summarizes ten crucial applications of cerebral ultrasonography for the evaluation and management of neurocritical patients, whose transfer from and to intensive care units poses a real problem to medical care staff. This also encompasses ease of use, low cost, wide acceptance by patients, no radiation risk, and relative independence from movement artifacts. Bedsides, availability and reliability raised the interest of critical care intensivists in using it with increasing frequency. In this mini-review, the usefulness and the advantages of US in the neurocritical care setting are discussed regarding ten aspects to encourage the intensivist physician to practice this important tool.

Assessment of Naturally Occurring Radionuclides Accumulation in Palm Oil from Soil

Hyper Pure Germanium (HPGe) radiation detector was used to estimate the activity concentration of fifteen soil and palm oil samples collected from the oil palm plantations in the southwestern, southeastern, and south southern states of Nigeria, and the risk assessments was evaluated. The activity concentrations at a soil depth 0 – 15 cm ranged from 187.4 to 514.4, 2.328 to 6.571, and 1.509 to 6.121 Bq/kg for 40K, 238U, and 232Th, respectively. The activity concentrations at a soil depth 15 – 30 cm ranged from 163.4 to 3188.8, 1.345 to 9.410, and 1.476 to 6.275 Bq/kg for 40K, 238U, and 232Th, respectively. The activity concentrations in the palm oil ranged from 122.3 to 968.0, 1.240 to 6.651, and 1.199 to 8.061 Bq/L for 40K, 238U, and 232Th. For the risk assessments of surface soil samples, the absorbed dose rate (D) ranged from 5.09 to 24.54 nGy/h, while the annual effective dose equivalent (E) ranged from 0.612 × 10-2 to 16.49 × 10-2 mSv/y. The radium equivalent, gamma absorbed dose rate, and the annual effective dose rate in the palm oil samples ranged from 9.981 to 88.00 Bq/L, 4.315 to 46.29 nGy/h, and 0.53 × 10-2 to 56.90 x 10-2 mSv/y, respectively. The activity concentrations reported for soil and palm oil samples were lower than the recommended world average values given by UNSCEAR. Hence, the hazard and risk assessments indicated a low radiation risk within the studied areas.

Occupational radiation safety studies in Nepal – a review

Occupational radiation safety and health is the most neglected aspect in the health sector in Nepal. There has been gross negligence in occupational safety and health as a whole in Nepal. This paper is a review of previously published articles on topics of occupational radiation safety and health in Nepal. Keywords such as Nepal, occupational safety, radiation safety, radiation risk, and health were used to search for relevant articles in PUBMED and Google Scholar. A total of 15 research articles were reviewed, which dealt with different forms of occupational radiation risks and exposure, regulatory works and consequently its knowledge and awareness among the professionals. The reviewed articles are basically of 3 types: analytical or progress reports, knowledge or awareness assessment, and measurement-based research articles. The overall status of occupational radiation safety and health does not look satisfactory. Although occupational radiation safety and health is a very important issue at an individual, social and national level in any hospital, agricultural or industrial sector, it has not received much attention so far in Nepal. This is evident by the minimal number of literature available on the status of occupational radiation safety and health in Nepal. Standard work situations and criteria have to be set up and regular radiation monitoring should be done to ensure the maintenance of quality at work. In addition, workshops, seminars, symposiums, training courses, and Continuing Professional Education (CPE) programs should be organized regularly to raise the level of radiation awareness in the profession. The state agencies need to develop and update respective national laws, policy and programs for occupational radiation safety and health. There is an utmost need for extensive researches to be performed covering overall radiation health and other services of the professionals in Nepal where radiation is being used for their advantageous purposes.

Urbanization, Electromagnetic Radiation and Sparrows: A Case Study from Guwahati, India

The persisting growth of wireless telecommunication technology causes increased electrosmog. Exposure to wide-ranging radiofrequency electromagnetic fields is thought to be a concern for all the living species across the globe. Studies have shown possible effects of electromagnetic radiation on various organisms including electromagnetic radiation risk on birds, but the outcomes were inconsistent. Here, we investigated if there is any impact of electromagnetic radiation on the abundance and habitat use of sympatric House Sparrow and Tree Sparrow in Guwahati City, India. In addition, we did a comparative analysis of previous work that had been conducted on possible effects of EMR on wild birds in field condition. We collected sparrow abundance in selected urbanization gradients temporally over a period of two years in 45 locations and spatially covering 168 locations in the eastern part of Guwahati City. Point counts were carried out, and successively we measured the electromagnetic radiation along with other ecological covariates. It was observed that ecological variables contributed significant variation to explain the habitat use of sparrows in Guwahati City compared to electromagnetic radiation. We observed that House Sparrow had quadratic relationship and Tree sparrow had negative association with increasing urbanization. Studies carried out in the past on the impacts of electromagnetic radiation on birds outside the lab condition had not considered other ecological covariates, which could also influence the life history needs of the bird species. Our study emphasized that the ecological covariates should be taken into consideration while studying the effect of electromagnetic radiation on wild organisms.

Development of the automated system for assessing radiation risks to the population of the Russian Federation based on the data of radiation-hygienic certification of territories

The assessment of the radiation risk based on the data of the radiation-hygienic passports of the territories makes it possible to give a brief quantitative characteristic of the negative impact of sources of ionizing radiation on the health of the population of various regions of the Russian Federation at the population level. The calculation of individual indicators of radiation risk for the population of particular region of the Russian Federation is a time-consuming task that requires referring to radiation-hygienic passports of territories for particular years. Therefore, the purpose of the performed work was to develop specialized software designed to assess the indicators of radiation risk to the population of the Russian Federation according to the data of the radiation-hygienic certification system of territories. Automation of the calculation of radiation risk allows not only to simplify the calculation procedure but also to carry out a spatial-temporal analysis of risk in dynamics for different regions of the Russian Federation over long periods. The methodological basis for the software development is guideline MR 2.6.1.0145-19 “Calculation of radiation risk according to the data contained in the radiation-hygienic passports of the territories to provide a comprehensive comparative assessment of the radiation safety status of the population of the subjects of the Russian Federation”. To achieve the set goal, two computer programs were developed: 1) to automate the process of calculating radiation risk based on the information contained in the radiation-hygienic passports of territories, a computer program “Calculation of radiation risk indicators according to RGPT data”; 2) for the spatial visualization of the calculations, a specialized geographic information system “Radiation risks of the population of the Russian Federation according to radiation-hygienic certification data”. The computer programs developed in the course of the work allow an automated calculation of radiation risk based on the data of radiation-hygienic passports of territories, visualize the spatially distributed results of calculating radiation risk, carry out a preliminary assessment of the state of radiation safety, based on the data contained in radiation-hygienic passports of territories using radiation risk indicators.

Estimating Radiotherapy-Induced Secondary Cancer Risk Arising from Brain Irradiation at High Energy: A Monte Carlo Study

Background: The present study aims to determine the whole-body out-of-field photon dose equivalents of high-energy conventional radiation therapy treatment. Also, it is tried to estimate the probability of fatal secondary cancer risk for the susceptible organs using a Monte Carlo (MC) code. Materials and methods: An Monte Carlo N-Particle eXtended (MCNPX)-based model of 18-MV Medical Linear Accelerator (LINAC) was created to calculate the out-of-field photon dose equivalent at the locations of fascinating organs in the mathematical female Medical Internal Radiation Dosimetry (MIRD) phantom. Then, the secondary malignancies risk was estimated based on out-of-field doses and radiation risk coefficients according to the National Council of Radiation Protection and Measurements (NCRP). Results: The average photon equivalent dose in out-of-field organs was about 3.25 mSv/Gy, ranging from 0.23 to 37.2 mSv/Gy, respectively, for the organs far from the Planning Target Volume (PTV) (Eyes) and those close to the treatment field (rectum). The entire secondary cancer risk for the 60 Gy prescribed dose to isocenter was obtained as 2.9987%. Here, the maximum doses among off-field organs were related to stomach (0.0805%), lung (0.0601%), and thyroid (0.0404%). Conclusion: Regarding the estimated values for the probability of secondary cancer risk, it is suggested to perform a long-term follow-up of brain cancer patients regarding the prevalence of thyroid, stomach, and lung cancer after completing the treatment course.

Radioepidemiological studies in the Urals: outcomes and future directions

The paper presents the key milestones and outcomes of 65-year studies of the carcinogenic consequences of accidental radiation exposure of the population of the Urals region. The radioactive contamination of the Techa River and the 1957accident at the Mayak PA were the reasons for the long-term exposure of the population at a wide range of doses. The most important tasks of the study were the reconstruction of individual doses, follow-up of the health and life status of cohort members. The research results have shown that chronic human exposure, in comparison to acute exposure, does not reduce the risk of developing malignant tumors and leukemias, and the value of the dose-rate factor does not exceed “one”. Thus, according to our data, the current recommendations of the International Commission on Radiological Protection underestimate the radiation risk of malignant tumors and leukemias in case of chronic exposure of the population by a factor of two. Prospects for further radio-epidemiological studies in the Urals are associated with the analysis of the cohort of Southern Urals Populations Exposed to Radiation (SUPER), which includes about 63 thousand exposed people and makes it possible to assess the radiation risk of solid cancers of certain localizations, certain types of leukemia, and non-cancer effects.

Comparison of Radiation Risk of Cancer Incidence among PA Mayak Workers Hired at Different Calendar Periods

Purpose: comparative epidemiological analysis of cancer incidence rates among PA Mayak workers hired at different calendar periods. Material and Methods: The cohort of PA Mayak workers hired at reactors, radiochemical, plutonium, water preparing and repair plants in 1948-1982 was selected for analysis of solid cancer (except lung, liver and bone) incidence. The cohort was divided into two subcohorts 1948-1958 and 1959-1982 years of hire. Regression models of relative risk included the description of background rates and excess radiation risk was used. Results: The radiation relative risk per 1 Gy was (ERR/Gy: 0.11; 95 % CI: 0.02; 0.21) in the subcohort of workers hired in 1948–1958 and was close to the estimates from previous studies for the whole cohort. In the subcohort of workers hired in 1959–1982 the point estimate of ERR/Gy was 3 times higher than in the subcohort 1948–1958 years of hire, but it was not statistically significant in the whole dose range. Restriction of doses up to 2 Gy allowed to get significant estimate of ERR/Gy (0.45; 95 % CI: 0.04; 0.95), which 4 times higher the estimate in the first subcohort calculated with the same restriction (0.11; 95 % CI: -0.01; 0.25). All subcohorts differences were not statistically significant and we can say about point distinctions only.