49 results match your criteria: "Ningyo-Toge Environmental Engineering Center[Affiliation]"

Microscopic structures in liquid-liquid extraction, such as structuration between extractants or extracted complexes in bulk organic phases and at interfaces, can influence macroscopic phenomena, such as the distribution behavior of solutes, including extraction efficiency and selectivity. In this study, we correlated the macroscopic behavior of the Zr(IV) extraction from nitric acid solutions with microscopic structural information to understand at the molecular level the key factors contributing to the higher metal ion extraction performance in the fluorous extraction system as compared to the analogous organic extraction system. The fluorous and organic extraction systems consist of tris(4,4,5,5,6,6,7,7,7-nonafluoroheptyl) phosphate (TFP) in perfluorohexane and tri--heptyl phosphate (THP) in -hexane, respectively.

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Radon is a known risk factor for lung cancer; however, it can be used beneficially, such as in radon therapy. We have previously reported the enhancement of antioxidant effects associated with trace amounts of oxidative stress as one of the positive biological effects of radon inhalation. However, the biological effects of radon inhalation are incompletely understood, and more detailed and comprehensive studies are required.

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Rapid sand filters (RSFs) are employed in a drinking water treatment to remove undesirable elements such as suspended solids and dissolved metal ions. At a closed uranium (U) mine site, two sets of tandemly linked paired RSF systems (RSF1-RSF2 and RSF1-RSF3) were utilized to remove iron and manganese from mine water. In this study, a 16S rRNA-based amplicon sequencing survey was conducted to investigate the core microbes within the RSF system treating the mine water.

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Soil cover is a prevailing method used at mine sites to ensure the safety of hazardous materials and restore ecological functions when the base materials are unfavorable for plant growth. The former open-pit Ningyo-toge Mine was backfilled with overburden and neutralized smelting residues and covered with soil in 1987. After 36 years, the vegetation remained dominated by the perennial herb Miscanthus sinensis, and woody plant establishment did not progress successfully.

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Variation analysis of atmospheric Be activity concentrations with respect to precipitation.

J Environ Radioact

July 2024

Central Institute of Radioisotope Science and Safety Management, Kyushu University (Professor Emeritus), 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.

Beryllium-7 activity concentrations in the atmosphere and precipitation were continuously measured every day between April 2011 and December 2015 in Dazaifu, western Japan. The measured data were quantitatively analyzed to determine the precipitation-induced variation in Be activity concentrations. The average concentrations on nonprecipitation and precipitation days were 5.

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In this study, we successfully applied a transition-edge sensor (TES) spectrometer as a detector for microbeam X-ray measurements from a synchrotron X-ray light source in the hard X-ray region to determine uranium (U) distribution at the micro-scale and its chemical species in biotite obtained from a U mine. It is difficult to separate the fluorescent X-ray of the U Lα line at 13.615 keV from that of the Rb Kα line at 13.

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Microbially formed Mn(IV) oxide as a novel adsorbent for removal of Radium.

Chemosphere

May 2024

Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki, 319-1195, Japan; Subatech, UMR 6457 IMT-Atlantique, Université de Nantes CNRS/IN2P3, Nantes, France.

Radioactivity of Ra isotopes in natural waters is of serious concern. Control of Ra concentrations in tailings ponds, which store waste from U ore extraction processes, is an important issue in mill tailings management. In this study, we tested microbially formed Mn(IV) oxide as an adsorbent for removal of Ra in water treatment.

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The impacts of mathematical models and associated parameters on radon (Rn) and thoron (Rn) exhalation rates based on in-situ testing at building interior solid walls were demonstrated to improve data analysis techniques. The results showed that the heterogeneity of their activity concentrations within the measurement system was more significant for thoron than radon. The diurnal variation in indoor radon should be considered for better data quality.

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Molecular geochemistry of radium: A key to understanding cation adsorption reaction on clay minerals.

J Colloid Interface Sci

May 2024

Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; Isotope Science Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan.

Article Synopsis
  • Different cations interact with clay minerals in contrasting ways, forming either outer-sphere or inner-sphere complexes, which significantly affects their environmental behaviors.
  • This study is the first to investigate how radium (Ra) adsorbs onto clay minerals using EXAFS, revealing that Ra forms inner-sphere complexes on vermiculite despite its typical hydration preference.
  • The research identified key factors influencing these complex formations, emphasizing the role of ionic radius and hydration enthalpy, and connected findings to environmental implications by analyzing core samples that show Ra's fixation by clay minerals.
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Coprecipitation of radionuclides with barite has been studied to remove radionuclides from radioactive liquid waste because of its excellent removal efficiency; however, little information exists concerning the stability of the ions coprecipitated with barite. This study systematically investigated the stability of iodate, selenite, and selenate coprecipitated with barite via leaching tests. These oxyanions were gradually leached from the oxyanion-bearing barite into ultrapure water over time.

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Implication of E3 ligase RAD18 in UV-induced mutagenesis in human induced pluripotent stem cells and neuronal progenitor cells.

J Radiat Res

March 2023

Laboratory for Zero-Carbon Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550  Japan.

Pluripotent stem cells (PSCs) have the potential to differentiate to any of the other organs. The genome DNA integrity of PSCs is maintained by a high level of transcription for a number of genes involved in DNA repair, cell cycle and apoptosis. However, it remains unclear how high the frequency of genetic mutation is and how these DNA repair factors function in PSCs.

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Biogenic manganese (Mn) oxides occur ubiquitously in the environment including the uranium (U) mill tailings at the Ningyo-toge U mine in Okayama, Japan, being important in the sequestration of radioactive radium. To understand the nanoscale processes in Mn oxides formation at the U mill tailings site, Mn absorption by a basidiomycete fungus, Coprinopsis urticicola, isolated from Ningyo-toge mine water samples, was investigated in the laboratory under controlled conditions utilizing electron microscopy, synchrotron-based X-ray analysis, and fluorescence microscopy with a molecular pH probe. The fungus' growth was first investigated in an agar-solidified medium supplemented with 1.

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Changes in Sulfur Metabolism in Mouse Brains following Radon Inhalation.

Int J Environ Res Public Health

August 2022

Faculty of Health Sciences, Okayama University, 5-1 Shikata-cho 2-chome, Kita-ku, Okayama 700-8558, Japan.

Therapy using hot springs, including the high-level radioactive gas "radon", is traditionally conducted as an alternative treatment for various diseases. Oxidative-stress-related diseases are inhibited by the enhancement of antioxidative functions following radon inhalation. We have reported that radon inhalation increased the level of anti-oxidants, such as glutathione (G-SH), in the brain and had a protective antioxidative effect against transient global cerebral ischemic injury.

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Testing mosses exposed in bags as biointerceptors of airborne radiocaesium after the Fukushima Dai-ichi Nuclear Power Station accident.

Chemosphere

December 2022

Fukushima Environmental Evaluation Research Division, Japan Atomic Energy Agency (JAEA), Japan.

Eight years after the Fukushima nuclear accident, mosses exposed in bags were used to investigate their ability to accumulate radiocaesium and therefore to act as biointerceptors of Cs and Cs in the evacuated area of the Fukushima territory. Bags were filled with 3 widely studied moss species (Sphagnum palustre, Hypnum cupressiforme, and Hypnum plumaeforme) and exposed for 3, 6 or 9 weeks at 5 former residential sites within the Fukushima area and, for comparison, at three background sites located 700 km away. The radiocaesium activity concentrations found in moss bags were evaluated as function of exposure time, site conditions and moss species.

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Analysis of Factors Contributing to the Increase in Be Activity Concentrations in the Atmosphere.

Int J Environ Res Public Health

August 2022

Central Institute of Radioisotope Science and Safety Management, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.

In March 2013, increased Be activity concentrations in the atmosphere were observed for successive days in Dazaifu, western Japan. The daily Be activity concentration ranged from 0.93 to 14 mBq/m, with a monthly average of 8.

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While online working seems to have become more common since the start of the Covid-19 pandemic, social media has the potential to offer greater interactivity and networking capacities. Thus it seems relevant for the IRPA Young Generation Network to investigate the use of social media by members of the young generation in radiation protection (RP) through an online survey. It was also the opportunity to collect early feedback about on-line learning.

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Although thoron inhalation exerts antioxidative effects in several organs, there are no reports on whether it inhibits oxidative stress-induced damage. In this study, we examined the combined effects of thoron inhalation and ascorbic acid (AA) administration on alcohol-induced liver damage. Mice were subjected to thoron inhalation at 500 or 2000 Bq/m3 and were administered 50% ethanol (alcohol) and 300 mg/kg AA.

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Radon Solubility and Diffusion in the Skin Surface Layer.

Int J Environ Res Public Health

June 2022

Graduate School of Health Sciences, Okayama University, 5-1 Shikata-cho 2-chome, Kita-ku, Okayama 700-8558, Japan.

In specific situations such as bathing in a radon spa, where the radon activity concentration in thermal water is far higher than that in air, it has been revealed that radon uptake via skin can occur and should be considered for more precise dose evaluation. The primary aim of the present study was to numerically demonstrate the distribution as well as the degree of diffusion of radon in the skin, with a focus on its surface layer (i.e.

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This study was conducted to find out characteristics of trace element levels and those impacts to organisms at a former uranium (U) mining site. Concentrations of trace elements (Li, Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Cd, Cs, Ba, Pb, Bi, and U) were determined in sediments, water, and three organism types (insects, frogs, and newts) from three zones in the former U mining site, Ningyo-toge in Japan. Concentrations of As and U in the sediments and water samples were the highest at the mill tailings pond (MP) site, where post-U extraction remnants have been accumulated.

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Mechanisms of action of radon therapy on cytokine levels in normal mice and rheumatoid arthritis mouse model.

J Clin Biochem Nutr

March 2022

Graduate School of Health Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama-shi, Okayama 700-8558, Japan.

The typical indication of radon therapy is rheumatoid arthritis. Although there are several reports that radon therapy has regulation effects on Th17 cells, there has been no study reporting that radon inhalation affects the immune balance among Th1, Th2, and Th17. The purpose of this study is to examine the cytokine changes after radon inhalation.

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Status of radon exposure in Bangladeshi locations and dwellings.

Environ Monit Assess

November 2021

Department of Environment Systems, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa campus, Chiba, 277-8561, Japan.

Potentially higher cancer risk due to exposure from natural background radiation was indicated for the Bangladeshi population by estimations based on the countrywide study. Several regions with elevated natural background exhibited higher soil radium and thorium contents than the world average. Being the decay products of these radioactive elements, natural radon isotopes could constitute environmental risk factors for internal radiation exposure to the lungs of people living in these areas.

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Radon inhalation decreases DNA damage induced by oxidative stress in mouse organs via the activation of antioxidative functions.

J Radiat Res

September 2021

Graduate School of Health Sciences, Okayama University, 5-1 Shikata-cho, 2-chome, Kita-ku, Okayama-shi, Okayama 700-8558, Japan.

Radon inhalation decreases the level of lipid peroxide (LPO); this is attributed to the activation of antioxidative functions. This activation contributes to the beneficial effects of radon therapy, but there are no studies on the risks of radon therapy, such as DNA damage. We evaluated the effect of radon inhalation on DNA damage caused by oxidative stress and explored the underlying mechanisms.

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The particle size distributions of airborne aerosols with Be were measured using cascade impactors at Dazaifu, a city in western Japan, in 2018 to observe their seasonal variation. Beryllium-7 was found to be adsorbed to aerosols with a particle size of less than 2.1 μm; in general, particles sized 0.

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Numerical reproduction of dissolved U concentrations in a PO-treated column study of Hanford 300 area sediment using a simple ion exchange and immobile domain model.

J Environ Radioact

October 2021

Department of Applied Energy, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya-shi, 464-8603, Japan.

We succeeded at numerical reproduction of dissolved U concentrations from column experiments with PO-treated Hanford 300 Area sediment using a simple ion exchange and immobile domain model. The time-series curves of dissolved U concentrations under various Darcy flow rate conditions were reproduced by the numerical model in the present study through optimization of the following parameters: the mass of U in mobile domain (on surface soil connected to the stream) to fit the starting U concentration at the column exit, and the rest of the total U was left as precipitation in immobile domain (isolated in deep soil); the mixing ratio between immobile and mobile domains, to fit the final recovering curve of concentration; and the cation exchange capacity (CEC) and equilibrium constant (k) of the exchange reaction of UO and H on simulated soil surface (Z), to fit the transient equilibrium concentration, forming the bed of the bathtub curve. Numerical setting of no U in immobile domain or no mixing between immobile and mobile domains caused all U flushed out of the column exit, and setting of no CEC on Z formed no transient equilibrium concentration.

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