A Review of Studies on Thyroid Dose Estimation After the Fukushima Accident

Estimates of thyroid doses to the public from radioiodine intake following the accidents at Chernobyl and Fukushima Daiichi nuclear power plants are compared. The basis for thyroid dose estimates after the Chernobyl accident was a large set of measurements of 131I thyroidal content for approximately 400,000 residents in Belarus, Ukraine, and Russia. Due to a lack of direct thyroid measurements after the Fukushima accident (just over 1000 residents were measured), thyroid doses were estimated based on ecological models and are therefore associated with much higher uncertainty than those based on direct thyroid measurements. Thyroid dose estimates for evacuees were up to 50,000 mGy for Chernobyl and up to approximately 100 mGy for Fukushima. This large difference in thyroid dose to the public is mainly due to the different dominant pathways of radioiodine intake: ingestion of fresh, locally produced cows’ milk (Chernobyl) and inhalation of contaminated air (Fukushima).

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Automated Cytogenetic Biodosimetry at Population-Scale

Radiation ◽

10.3390/radiation1020008 ◽

2021 ◽

Vol 1 (2) ◽

pp. 79-94

Author(s):

Peter K. Rogan ◽

Eliseos J. Mucaki ◽

Ben C. Shirley ◽

Yanxin Li ◽

Ruth C. Wilkins ◽

...

Keyword(s):

High Performance ◽

Large Scale ◽

Dicentric Chromosome ◽

Automated Assignment ◽

Simulated Population ◽

Dose Estimation ◽

Processing Times ◽

Multiple Processors ◽

Exposure Levels ◽

Population Scale

The dicentric chromosome (DC) assay accurately quantifies exposure to radiation; however, manual and semi-automated assignment of DCs has limited its use for a potential large-scale radiation incident. The Automated Dicentric Chromosome Identifier and Dose Estimator (ADCI) software automates unattended DC detection and determines radiation exposures, fulfilling IAEA criteria for triage biodosimetry. This study evaluates the throughput of high-performance ADCI (ADCI-HT) to stratify exposures of populations in 15 simulated population scale radiation exposures. ADCI-HT streamlines dose estimation using a supercomputer by optimal hierarchical scheduling of DC detection for varying numbers of samples and metaphase cell images in parallel on multiple processors. We evaluated processing times and accuracy of estimated exposures across census-defined populations. Image processing of 1744 samples on 16,384 CPUs required 1 h 11 min 23 s and radiation dose estimation based on DC frequencies required 32 sec. Processing of 40,000 samples at 10 exposures from five laboratories required 25 h and met IAEA criteria (dose estimates were within 0.5 Gy; median = 0.07). Geostatistically interpolated radiation exposure contours of simulated nuclear incidents were defined by samples exposed to clinically relevant exposure levels (1 and 2 Gy). Analysis of all exposed individuals with ADCI-HT required 0.6–7.4 days, depending on the population density of the simulation.

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A Search for Causes of Rising Incidence of Differentiated Thyroid Cancer in Children and Adolescents after Chernobyl and Fukushima: Comparison of the Clinical Features and Their Relevance for Treatment and Prognosis

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18073444 ◽

2021 ◽

Vol 18 (7) ◽

pp. 3444

Author(s):

Valentina Drozd ◽

Vladimir Saenko ◽

Daniel I. Branovan ◽

Kate Brown ◽

Shunichi Yamashita ◽

...

Keyword(s):

Thyroid Cancer ◽

Children And Adolescents ◽

Differentiated Thyroid Cancer ◽

Age Groups ◽

Distant Metastases ◽

Lifestyle Changes ◽

Radiation Doses ◽

Related Factors ◽

Fukushima Accident ◽

Tumor Stages

The incidence of differentiated thyroid cancer (DTC) is steadily increasing globally. Epidemiologists usually explain this global upsurge as the result of new diagnostic modalities, screening and overdiagnosis as well as results of lifestyle changes including obesity and comorbidity. However, there is evidence that there is a real increase of DTC incidence worldwide in all age groups. Here, we review studies on pediatric DTC after nuclear accidents in Belarus after Chernobyl and Japan after Fukushima as compared to cohorts without radiation exposure of those two countries. According to the Chernobyl data, radiation-induced DTC may be characterized by a lag time of 4–5 years until detection, a higher incidence in boys, in children of youngest age, extrathyroidal extension and distant metastases. Radiation doses to the thyroid were considerably lower by appr. two orders of magnitude in children and adolescents exposed to Fukushima as compared to Chernobyl. In DTC patients detected after Fukushima by population-based screening, most of those characteristics were not reported, which can be taken as proof against the hypothesis, that radiation is the (main) cause of those tumors. However, roughly 80% of the Fukushima cases presented with tumor stages higher than microcarcinomas pT1a and 80% with lymph node metastases pN1. Mortality rates in pediatric DTC patients are generally very low, even at higher tumor stages. However, those cases considered to be clinically relevant should be followed-up carefully after treatment because of the risk of recurrencies which is expected to be not negligible. Considering that thyroid doses from the Fukushima accident were quite small, it makes sense to assess the role of other environmental and lifestyle-related factors in thyroid carcinogenesis. Well-designed studies with assessment of radiation doses from medical procedures and exposure to confounders/modifiers from the environment as e.g., nitrate are required to quantify their combined effect on thyroid cancer risk.

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Satellite-Based Personal UV Dose Estimation

Atmosphere ◽

10.3390/atmos12020268 ◽

2021 ◽

Vol 12 (2) ◽

pp. 268

Author(s):

Todd C. Harris ◽

Laurent Vuilleumier ◽

Claudine Backes ◽

Athanasios Nenes ◽

David Vernez

Keyword(s):

Measurement Errors ◽

Low Cost ◽

Public Health Research ◽

Mobile App ◽

Population Exposure ◽

Dose Estimation ◽

Annual Dose ◽

Significant Step ◽

Uv Dose ◽

Dosimetry Measurement

Epidemiology and public health research relating to solar ultraviolet (UV) exposure usually relies on dosimetry to measure UV doses received by individuals. However, measurement errors affect each dosimetry measurement by unknown amounts, complicating the analysis of such measurements and their relationship to the underlying population exposure and the associated health outcomes. This paper presents a new approach to estimate UV doses without the use of dosimeters. By combining new satellite-derived UV data to account for environmental factors and simulation-based exposure ratio (ER) modelling to account for individual factors, we are able to estimate doses for specific exposure periods. This is a significant step forward for alternative dosimetry techniques which have previously been limited to annual dose estimation. We compare our dose estimates with dosimeter measurements from skiers and builders in Switzerland. The dosimetry measurements are expected to be slightly below the true doses due to a variety of dosimeter-related measurement errors, mostly explaining why our estimates are greater than or equal to the corresponding dosimetry measurements. Our approach holds much promise as a low-cost way to either complement or substitute traditional dosimetry. It can be applied in a research context, but is also fundamentally well-suited to be used as the basis for a dose-estimating mobile app that does not require an external device.

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Influence of sorption parameters on cesium-137 removal using modified activated carbon obtained from corchorus olitorius stalks

Radiochimica Acta ◽

10.1515/ract-2020-0012 ◽

2020 ◽

Vol 108 (10) ◽

pp. 799-808

Author(s):

Mostafa M. Hamed ◽

Mahmoud M. S. Ali ◽

Aly A. Helal

Keyword(s):

Natural Waters ◽

Low Cost ◽

Radioactive Cesium ◽

Corchorus Olitorius ◽

Fukushima Accident ◽

Modified Activated Carbon ◽

Cesium Ions ◽

Cesium 137 ◽

Sorption Parameters ◽

Surface And Groundwater

AbstractRemoval of 137Cs radionuclides from the environment has engrossed the concern of researchers after Fukushima accident. The leakage of radioactive cesium ions can lead up to surface and groundwater contamination, and this leads to pollution of drinking water sources. In this work, corchorus olitorius stalks has been used as a novel precursor for production of low-cost mesoporous activated carbon (Meso-AC) and HNO3/H2O2-modified Meso-AC (m-Meso-AC). The physicochemical properties of all adsorbents were evaluated. The influences of sorption parameters and presence of some ligands (humic acid, fulvic acid, and EDTA) on the sorption of 137Cs were studied. The maximum 137Cs capacity of m-Meso-AC was found to be 58.74 mg/g. Efficiency of the new adsorbent to remove 137Cs radionuclides from natural waters (tap, river, and groundwater) was investigated. The studies showed that new adsorbent could be used as promising material for the retention of 137Cs from real radioactive waste and natural water samples.

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