Health Phys. Abstracts，Volume 121,Number 6

AComparisonofCurrentMethodsfortheDeterminationofRa-226andRa-228inWaterbyaModifiedGeorgiaTechGammaMethodVs.USEnvironmentalProtectionAgencyDrinkingWaterMethodologies

Dao M. Nguyen, W. Allen Moody, John A. Williamson1

(1.Florida Department of Health, Bureau of Radiation Control, 4052 Bald Cypress Way, Bin C21, Tallahassee, FL 32399-1741)

Abstract:Radium is a significant source of human radiation exposure both from natural sources (NORM, or Naturally Occurring Radioactive Material) and from technologically enhanced natural radioactive material (TENORM). Gamma analysis for226Ra and228Ra in water using high purity germanium (HPGe) detectors was compared with current methods from the US Environmental Protection Agency (EPA) using alpha scintillation and gas proportional counters. Extensive evaluations of a modified version of the original Georgia Tech HPGe method were performed. Known value226Ra samples from the US Department of Energy (DOE) Mixed-Analyte Performance Evaluation Program (MAPEP) program, mixed226Ra and228Ra samples from the Environmental Resource Associates Quality Assurance Program (ERA), and mixed226Ra and228Ra samples from the Laboratory Proficiency Testing Program of the International Atomic Energy Agency (IAEA) were used for cross-check comparisons of the modified Georgia Tech method with other methodologies (EPA 903.1 and Ra-05 for226Ra and228Ra, respectively). Minimum counting times for our gamma instrumentation to reach a minimum detectable activity (MDA) of 0.04 Bq L-1were also determined.

Keywords:226Ra;228Ra; radium analysis; minimum detectable activity; gamma spectroscopy

Health Phys. 121(6):558-563; 2021

ProteomicBiomarkerAnalysisofSerumfromJapaneseFieldMice(Apodemus Speciosus)CollectedwithintheFukushimaDifficult-to-returnZone

Mary Sproull1†, Joshua Hayes2,4†, Hiroko Ishiniwa3, Kenji Nanba3, Uma Shankavaram1, Kevin Camphausen1, Thomas E. Johnson2

(1.Radiation Oncology Branch, National Cancer Institute, Bethesda, MD;2.Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO;3.Institute of Environmental Radioactivity, Fukushima University, Fukushima, Japan;4.International Atomic Energy Agency, Vienna, Austria)

Abstract:The environmental impact of the Fukushima Daiichi nuclear power plant accident is a source of ongoing concern as there is uncertainty regarding the effects of chronic radiation exposure on local plant and animal life from Fukushima-derived radionuclides. In the current study, changes in proteomic biomarker expression due to chronic environmentally-derived radiation exposures was examined in wild field mice. Serum from 10 wild field mice (Apodemusspeciosus) native to the Fukushima difficult-to-return zone and from eight wild field mice native to the Soma area (control) were collected. External dose estimations were completed using measurements of ambient radiation levels and calculating137Cs concentrations in soil. Internal dose was estimated by counting whole mice using an HPGe detector. Age of the mice was estimated using molar wear. Serum was screened using the aptamer-based SOMAscan proteomic assay technology for changes in expression of 1,310 protein analytes. A subset panel of protein biomarkers that demonstrated significant changes in expression between control and exposed mice was determined and analyzed using Ingenuity Pathway Analysis (IPA). Control animals had a calculated lifetime dose range from 0.001 to 0.007 Gy, and exposed animals had a calculated lifetime dose range from 0.01 to 0.64 Gy. No discernable effect of dose rate was seen as relative dose rate correlated with dose for all samples. Detectable values were obtained for all 1,310 proteins included in the SOMAscan assay. Subset panels of proteins demonstrating significant (p<0.05) changes in expression with either an upregulated or downregulated 1.5-fold change over control were identified for both the sample cohort inclusive of all exposed samples and the sample cohort restricted to samples from animals receiving “low” dose exposures. These panels of proteins from exposed animals were analyzed using IPA, which highlighted changes in key biological pathways related to injury, respiratory, renal, urological, and gastrointestinal disease, and cancer. Significant changes in expression of proteomic biomarkers were seen in the serum of wild field mice that received environmental exposure to Fukushima-derived radionuclides. Our findings demonstrate novel biomarkers of radiation exposure in wildlife within the Fukushima difficult-to-return zone.

Keywords:137Cs; biological indicators; Fukushima Daiichi; health effects

Health Phys. 121(6):564-573; 2021

ASummaryofResidentialRadonSurveysandtheInfluenceofHousingCharacteristicsonIndoorRadonLevelsinCanada

Jing Chen1

(1.Radiation Protection Bureau, Health Canada, 775 Brookfield Road, Ottawa K1A1C1, Ontario, Canada)

Abstract:Based on community and nationwide radon surveys with long-term radon measurements in a total of 21,818 homes, radon distribution characteristics in Canada have been reassessed with the population-weighted arithmetic mean radon concentration of 82 Bq m-3, geometric mean radon concentration of 55 Bq m-3, and geometric standard deviation of 2.45. The major pathway for the influx of radon into Canadian homes is from the surrounding soil. Statistical analysis has shown that radon levels in houses with a basement are, on average, about twice the radon levels in houses without a basement, and houses with private wells also tend to have higher radon concentrations than houses with municipal water supply.

Keywords:222Rn;222Rn; indoor; health effects; radioactivity; indoor

Health Phys. 121(6):574-580; 2021

Sex-relatedDifferencesinAirwayDimensions:AStudyBasedonQuantitativeComputedTomographyamongChinesePopulation

Nan Yu, Guangming Ma, Haifeng Duan, Youmin Guo, Yong Yu, Shan Dang1

(1.Radiology Department, Shaanxi University of Chinese, Western Road, 2#, Xian Yang, China)

Abstract:Sex-dependent radiation injury may be related to the differences in physiological characteristics between the sexes. This study aimed to better understand variations in airway dimensions among male and female Chinese non-smokers. This study included 970 adults and 45 children who underwent chest CT. All participants were non-smokers, without current or former chronic pulmonary disease, and all underwent CT examination. The CT images were quantitatively assessed, providing airway dimensions. The differences in inner diameter, wall thickness, wall area (WA), and WA% for each airway were compared between male and female patients. Sex is an important influencing factor in airway morphological parameters. These parameters are different between men and women: men have a larger airway diameter (P<0.05) and smaller wall area (WA%,P<0.05) compared with women. Younger women (<35 years) have a greater diameter and smaller WA% compared with older women (P<0.05). Sex-related differences in airway morphology were not observed in pediatric participants. Significant differences were found in quantitative CT measures of WA% and an internal diameter among non-smokers of varying sex. The differences found in this study might explain, in part, sex-dependency of radiation injury and a possible radiological protection scheme.

Keywords: cancer; computed tomography; diagnostic imaging; radiation protection

Health Phys. 121(6):581-586; 2021

BackwardEstimationofAtmosphericReleaseof137Csand131IUsingTotalCumulativeDepositioninTerrestrialAreasFollowingtheFukushimaDaiichiNuclearPowerPlantAccident

Masashi Iijima1,2, Shogo Takahara1

(1.Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan;2. Visible Information Center, Inc., 440 Muramatsu, Tokai-mura, Naka-gun, 319-1112, Japan)

Abstract:The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident caused a significant release of radionuclides into the environment. It is important to explore the timing and amount of radioactive release to terrestrial areas in order to clarify the consequences of the accident, including the dose received by the population living in the areas affected by the accident. In general, backward estimations are performed using air concentrations of radionuclides, but they are difficult to measure when radioactive plumes are passing through, and only spatially and temporally limited measurements are available. Therefore, a new method of backward estimation was developed based on the total cumulative deposition density, which can provide sufficient data in the environment by combining the atmospheric transport, dispersion, and deposition model calculations. Consequently, our estimations show that a major release of137Cs and131I occurred on 15, 20, 21, 22, 25, and 30 March 2011, after the accident. The amounts of release estimated by our new method for137Cs and131I were 4.9×1015Bq and 120×1015Bq, respectively. These results have no significant contradiction with the estimated results by the previous studies that were based on air concentrations and air dose rates that were measured in terrestrial areas. It was found that our new method is applicable for backward estimation oriented to the dose assessment for the people living in terrestrial areas.

Keywords: accidents; power reactor; atmospheric testing; dose assessment; Fukushima Daiichi

Health Phys. 121(6):587-596; 2021

The“BrookhavenBrassie”andtheResponsetotheThreeMileIslandAccident

Nicholas M. Studer1

(1.National Museum of Civil Defense, PO Box 784, Randolph AFB, TX 78148-0784)

Abstract:In the mid-1970s, American civil defense authorities became increasingly concerned with the potential threat of fission reactor accidents. Research from the Defense Civil Preparedness Agency began to be aimed not just at the ever-present threat of nuclear warfare but also peacetime emergencies as part of a “dual use” philosophy. The Brookhaven National Laboratory received funding to create a prototype radioiodine air sampling system, with multiple publications detailing the creation of the air sampler itself and a special CD V-700 survey meter that accompanied it. In late March 1979, the system found its first operational employment at the reactor accident at Three Mile Island in Pennsylvania. Despite successful use and further study, the BNL Air Sampler was not widely fielded by the federal government. However, lessons learned from its employment and development may be applicable to contemporary radiological emergency response.

Keywords: accidents; nuclear; accidents power reactor; emergencies; radiological; emergency planning

Health Phys. 121(6):597-601; 2021

TestingDecisionLevel(DL)andMinimumDetectableAmount(MDA)forHanfordInVivoCountingSystems

Brett L. Rosenberg, Timothy P. Lynch1, Cheryl L. Antonio1

(1. Hanford Mission Integration Solutions, Radiological Site Service, PO Box 650, MSIN S3-28, Richland, WA 99352)

Abstract:Testing the decision level (DL) and minimum detectable amount (MDA) of a radionuclide for a direct bioassay (in vivo) counting system is a requirement for in vivo monitoring programs across the DOE complex. Bottle manikin absorption (BOMAB) and torso phantoms are used in conjunction with point sources to facilitate the testing. This paper describes a method of testing the DL and MDA values of in vivo counting systems with equipment commonly used by in vivo programs. This method is cost effective and minimizes waste since the radiological sources used can have broad ranges for decay activities. The results from the testing indicated that the current DL and MDA values are valid for the equipment and methods used at the Hanford in vivo counting facility.

Keywords: operational topics; minimum detectable activity; monitoring; personnel; spectrometry; gamma

Health Phys. 121(6):607-612; 2021

JointEnvironmentalRadiationSurveybyJAEAandKAERIAroundtheFukushimaDaiichiNuclearPowerPlant:PerformanceofMobileGamma-RaySpectrometryUsingBackpackandCarborneSurveyPlatforms

Young-Yong Ji1, Kotaro Ochi2, Sang Bum Hong1, Shigeo Nakama2, Yukihisa Sanada2, Satoshi Mikami3

(1. Korea Atomic Energy Research Institute, Daejeon 34057, Republic of Korea;2. Japan Atomic Energy Agency, Fukushima 975-0036, Japan;3. Japan Atomic Energy Agency, Ibaraki 311-1206, Japan)

Abstract:According to the implementing arrangement between the Japan Atomic Energy Agency (JAEA) and the Korea Atomic Energy Research Institute (KAERI) in the field of radiation protection and environmental radiation monitoring, a joint survey program was performed to assess ground deposition of radioactive cesium in areas surrounding the Fukushima Daiichi Nuclear Power Plants. The purpose of this joint survey was to evaluate the field applications of the developed survey systems and methodologies. Understanding the performance of each system within a cesium-deposited contaminated zone is important for ensuring an appropriate response following a nuclear accident. The results of the measured ambient dose rates determined using each survey method were compared. Two kinds of survey system were used in the mobile gamma-ray spectrometry, which were MARK-M1 (Monitoring of Ambient Radiation of KAERI—the 1st Multipurpose system) based on two LaBr3(Ce) detectors of KAERI and KURAMA-II (Kyoto University Radiation Mapping - II) system with one CsI(Tl) detector of JAEA. First, mobile gamma-ray spectrometry using a backpack survey platform was conducted to assess the distribution of dose rates around specific survey sites, which were expected to be slightly contaminated by radioactive cesium in Minamisoma and Tomioka. A carborne survey using two gamma-ray spectrometers loaded inside a vehicle was successfully conducted to compare the measured dose rates in routes from site to site and verify evaluation methods, including attenuation correction.

Keywords: operational topics; Fukushima Daiichi; radiation; background; spectrometry; gamma-ray

Health Phys. 121(6):613-620; 2021