タイの原子力発電所周辺地域における環境試料中に含まれる天然放射線核種と希土類元素の分布 : ベースラインの確立に関する研究

首都大学東京, 2014-09-30, 博士（放射線学）, 甲第473号首都大学東

Distribution of rare earth elements, thorium and uranium in Gulf of Thailand\u27s sediment

Distribution of rare earth elements (REEs), thorium and uranium in fifty-four marine sediments collected from five selected areas along the Gulf of Thailand are discussed in this paper. These areas have been selected as potential sites to set up thermal and nuclear power plants. Concentration of elements was determined using inductively coupled plasma mass spectrometry (ICP-MS). Absolute concentrations of REEs, Th and U show a sample-to-sample variation and may be due to different geological characteristic of area as well as grain size effect. Total REE concentrations (not including Y) range between 9 μg/g and 210 μg/g. The chondrite-normalized REEs patterns of all samples are similar to Post Archaean Australian Shale (PAAS) and average Upper Continental Crust (UCC), with LREEs enrichment relative to HREEs (LaN/YbN = 6.5 – 29.3), fairly flat HREEs patterns (GdN/YbN = 1.0 – 3.8) and ubiquitous negative Eu-anomaly (Eu/Eu* = 0.3 – 0.7). Th concentrations (1 – 28 μg/g) are relatively higher than those of uranium (0.4 – 4 μg/g). Th/U ratios (1.5z – 9.9) are higher than the average upper crust. These results are consistent with terrigenous sediments that formed from the weathering and erosion of felsic rocks

Measurement of uranium,thorium and uranium activity ratio in environmental samples from a tropical country,Thailand

The scientific programme of the NRE9 will cover all aspects of natural radiation exposure including radon and thoron, any issues related to legislation problems and epidemiological studies. In addition, special session about Fukushima nuclear accident is planned.The 9th International Symposium on the Natural Radiation Environment(NRE-IX)に参加し、Measurement of uranium,thorium and uranium activity ratio in environmental samples from a tropical country,Thailandを発表す

Radiological risk assessment of 238U, 232Th and 40K in Thailand coastal sediments at selected areas proposed for nuclear power plant sites

This paper reports on the distribution of three natural radionuclides 238U, 232Th and 40K in marine sediments long the Gulf of Thailand to establish baseline data for future environmental monitoring. Sediments were collected from five potential sites selected for nuclear and thermal power plants commission as well as heavy industry development. Concentration of uranium and thorium were determined using inductively coupled plasma mass spectrometry (ICP-MS) as well as activity of 238U series (226Ra), 232Th series (228Ac) and 40K by γ-spectroscopy. The radiation hazard parameters were calculated based on United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Variation in concentration of natural radionuclides at different sampling areas could be attributed to organic matter content and sediment particle size. The radiological health hazards to the people living nearby sampling areas and the people who handle the marine sediments are within limits recommended by UNSCEAR

Distribution of Uranium and Some Selected Trace Metals in Human Scalp Hair from Balkans

The possible consequences of the use of depleted uranium (DU) used in Balkan conflicts in 1995 and 1999 for the people and the environment of this reason need attention. The heavy metal content in human hair may serve as a good indicator of dietary, environmental and occupational exposures to the metal compounds. The present work summarises the distribution of uranium and some selected trace metals such as Mn, Ni, Cu, Zn, Sr, Cd and Cs in the scalp hair of inhabitants from Balkans exposed to DU directly and indirectly, i.e. Han Pijesak, Bratoselce and Gornja Stub la areas. Except U and Cs, all other metals were compared with the worldwide reported values of occupationally unexposed persons. Uranium concentrations show a wide variation ranging from 0.9 +/- 0.05 to 449 +/- 12 mu g kg(-1). Although hair samples were collected from Balkan conflict zones, uranium isotopic measurement (U-235/U-238) shows a natural origin rather than DU.International Symposium on Natural Radiation Exposure and Low-dose Radiation Epidemiological Studies, Feb 29-Mar 03, 2012, Hirosaki Univ Inst Radiat Med, Hirosaki, Japa

DISTRIBUTION OF URANIUM IN URINE, HAIR AND NAILS IN RESIDENTS OF NISKA BANJA TOWN, A HIGH NATURAL BACKGROUND RADIATION AREA OF ERBIA

Quantification of uranium in human urine is a valuable technique for assessing occupant and public exposure to uranium. Human hair and nails can be considered as bio-indicators of the public exposure to certain natural radionuclides and toxic metals over a long period of months or even years. All urine, hair and nail samples were collected from a population of both sex aged from 40 to 87 years in Niška Banja (227 km south of Belgrade) with a high level of natural radioactivity (HLNRA), a suburban municipality of Serbia which located in the quaternary alluvium of River Nišava along the contact of the Koritnik limestone and travertine rock. Air dose rate in indoor environment has been measured. To assess and monitor the public exposure, urine samples for each subject (24 h period) were collected and concentration of uranium was analyzed using alpha-particle spectrometry. After addition of radioactive tracer U-232 and concentrated nitric acid, samples were evaporated to dryness. Residues were wet ashed with nitric acid and H2O2, radiochemical separationof uranium radioisotopes were performed by extraction chromatography using UTEVA resin. Uranium concentration in hair and nail samples from same subjects were analyzed using inductively coupled plasma mass spectrometry. Uranium concentrations in hair, nail and urine varied from 0.2 to77.1 ppb, 2.5 to 44.7 ppb, 54-730 ppb respectively. There was a large variation and may be due to geological origin and anthropogenic activities.9th International Conference on High Level Environmental Radiation Areas-For Understanding Chronic Low-Dose-Rate Radiation Exposure Health Effects and Social Impacts (ICHLERA 2018)

Distribution of uranium in urine, hair and nails in residents of Niska Banja town, a high natural background radiation area

Quantification of uranium in human urine is a valuable technique for assessing occupant and public exposure to uranium. Human hair and nails can be considered as bio-indicators of the public exposure to certain natural radionuclides and other toxic metals over a long period of months or even years.All urine, hair and nail samples were collected from a population of both sex aged from 40 to 87 years in Niška Banja (227 km south of Belgrade) with a high level of natural radioactivity (HLNRA), a suburban municipality, of Serbia which located in the quaternary alluvium of River Nišava along the contact of the Koritnik limestone and travertine rock. Air dose rate in indoor environment has been measured. To assess and monitor the public exposure, urine, hair and nail samples were collected to analyze the concentration of uranium, using inductively coupled plasma mass spectrometry and alpha-particle spectrometry. Uranium was determined in 24 h samples. After addition of radioactive tracer U-232 and concentrated nitric acid, samples were evaporated to dryness. Residues were wet ashed with nitric acid and H2O2, radiochemical separation of uranium radioisotopes were performed by extraction chromatography using UTEVA resin.Source preparation for alpha-particle spectrometry was carried out by the micro-coprecipitation method with neodymium fluoride.U concentrations in hair, nail and urine varied from 0.2 to 77.1 ppb, 2.5 to 44.7 ppb, 54-730 ppb respectively.There was a large variation and may be due to geological origin and anthropogenic activities

Measurement of uranium in urine, hair and nails in subjects of Niska Banja town, a high natural background radiation area of Serbia

Urine, hair and nail samples were collected from a population of both sex aged from 40 to 87 years in Niška Banja (227 km south of Belgrade, Serbia) with a high level of natural radioactivity (HLNRA). To assess and monitor the public exposure, urine samples for each subject (24 h period) were collected and concentration of uranium (U) was analysed using alpha-particle spectrometry. Human hair and nails considered as bio-indicators of the public exposure to radionuclides over a long period of months or even years and concentration of U was determined using inductively coupled plasma-mass spectrometry. The mean concentrations of U in urine, hair and nail were 123 ng/L, 17 ng/g and 8 ng/g, respectively. There was a large variation and may be due to geological origin