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Kanzaki, Norie; Sakoda, Akihiro; Kataoka, Takahiro*; Sun, L.*; Tanaka, Hiroshi; Otsu, Iwao*; Yamaoka, Kiyonori*
International Journal of Environmental Research and Public Health, 19(17), p.10750_1 - 10750_14, 2022/09
Times Cited Count：0 Percentile：0(Environmental Sciences)Reactive sulfur species (RSS) involve oxidative stress deeply and contribute anti-inflammatory effect, but no studied have focused on RSS changes after irradiation. In this study, we comprehensively analyzed the metabolites, focusing on RSS in mouse brain following radon inhalation. The ratio of oxidized glutathione to reduced glutathione and proportion of RSS in GSH or cysteine increased by radon inhalation. The sulfur ion might bind to GSH or cysteine chemically under conditions of oxidative stress, even at very low-dose exposure. We performed the overall assessment of high-dimensional data by applying machine learning and showed the specific characteristics of the effects by the exposure conditions. Our results suggested that RSS could produce a biological defense against oxidative stress following radon inhalation.
Kataoka, Takahiro*; Kanzaki, Norie; Sakoda, Akihiro; Shuto, Hina*; Yano, Junki*; Naoe, Shota*; Tanaka, Hiroshi; Hanamoto, Katsumi*; Terato, Hiroaki*; Mitsunobu, Fumihiro*; et al.
Journal of Radiation Research (Internet), 62(2), p.206 - 216, 2021/03
Times Cited Count：6 Percentile：61.83(Biology)Radon inhalation activates antioxidative functions in mouse organs, thereby contributing to inhibition of oxidative stress-induced damage. Therefore, in this study, we evaluated the redox state of various organs in mice following radon inhalation. Mice inhaled radon at concentrations of 2 or 20 kBq/m
for 1, 3, or 10 days. The relationship between antioxidative function and oxidative stress was evaluated by principal component analysis (PCA) and correlation coefficient compared with control mice subjected to sham inhalation. These findings suggested that radon inhalation altered the redox state in organs, but that the characteristics varied depending on the redox state in organs.
Omori, Yasutaka*; Hosoda, Masahiro*; Takahashi, Fumiaki; Sanada, Tetsuya*; Hirao, Shigekazu*; Ono, Koji*; Furukawa, Masahide*
Journal of Radiological Protection, 40(3), p.R99 - R140, 2020/09
Times Cited Count：22 Percentile：77.11(Environmental Sciences)UNSCEAR and the Nuclear Safety Research Association report the annual effective doses from cosmic rays, terrestrial radiation, inhalation and ingestion from natural sources. In this study, radiation doses from natural radiation sources in Japan were reviewed with the latest knowledge and data. Total annual effective dose from cosmic-ray exposure can be evaluated as 0.29 mSv. The annual effective dose from external exposure to terrestrial radiation for Japanese population can be evaluated as 0.33 mSv using the data of nationwide survey by the National Institute of Radiological Sciences. The Japan Chemical Analysis Center (JCAC) performed the nationwide radon survey using a unified method for radon measurements in indoor, outdoor and workplace. The annual effective dose for radon inhalation was estimated using a current dose conversion factor, and the values were estimated to be 0.50 mSv. The annual effective dose from thoron was reported as 0.09 mSv by UNSCEAR and then the annual effective dose from inhalation can be described as 0.59 mSv. According to the report of large scale survey of foodstuff by JCAC, the effective dose from main radionuclides due to dietary intake can be evaluated to be 0.99 mSv. Finally, Japanese population dose from natural radiation can be assessed as 2.2 mSv which is near to the world average value of 2.4 mSv.
Morishita, Yuki; Ye, Y.*; Mata, L.*; Pozzi, S. A.*; Kearfott, K. J.*
Radiation Measurements, 137, p.106428_1 - 106428_7, 2020/09
Times Cited Count：8 Percentile：60.71(Nuclear Science & Technology)We have developed a compact, organic-scintillator-based alpha/beta spectrometer for radon measurements and have characterized it using a unique, small radon chamber. The spectrometer is composed of a through-silicon via (TSV) silicon photomultiplier (or SiPM) and a 6 mm 
6 mm 6 mm stilbene crystal cube. Analog signals from the SiPM are sent to a digitizer. The detector is housed in a light-tight box, with a stacked air filter installed in one side of the box to enable 
Rn gas to diffuse to the inside. We conducted one experiment with the spectrometer and an AlphaGUARD detector placed in a basement at the University of Michigan, and we conducted other experiments with both detectors placed in a small radon chamber together with 
Ra sources. By applying a pulse-shape-discrimination technique, we were able to separate the alpha and beta spectra simultaneously and clearly and to measure them quantitatively. We found two peaks in the measured alpha spectrum: a lower-energy peak due to 
Po and a higher-energy peak due to 
Po. We found a linear relation between the radon concentration y from AlphaGUARD and the counting rates from the stilbene-SiPM detector. The alpha/beta spectrometer is less than 10 mm thick, and we expect that it will be easy to increase the sensitivity with future device construction. Thus, this compact, organic-scintillator-based alpha/beta spectrometer shows promise for use in novel radon-detection systems.
Tamakuma, Yuki*; Yamada, Ryohei; Iwaoka, Kazuki*; Hosoda, Masahiro*; Tokonami, Shinji*
Hoken Butsuri (Internet), 54(1), p.5 - 12, 2019/03
Airborne radioactivity measurements are necessary to know the contamination level and internal doses for residents after a nuclear accident. In addition, measurements of radon progenies in air, which are the risk factor of lung cancer, are also important to evaluate lung dose. In these measurements, a filter sampling is used to collect radioactive aerosols. However, it is well known that results of the measurement using a filter are strongly dependent on characteristics of the used filter. Selection of a suitable filter is important to achieve the high-resolution and long-term measurement. "Surface collection efficiency (SCE)" and "stability of air flow rate" were examined for six types of filter that are commercially available in Japan. In Japan, cellulose-glass fiber filter paper (HE-40T) is used for an environmental monitoring in Japan. In this study, it was found that the SCE of HE-40T was lower than that of mixed cellulose ester type membrane filter by Merck Millipore (DAWP02500). Attenuation ratio of flow rate for DAWP02500 was evaluated to be 2.9% which was lowest in six filters. The results suggest that the DAWP02500 is the most suitable for collecting radioactive aerosols for a long term.
Sasaoka, Kaori*; Kataoka, Takahiro*; Kanzaki, Norie; Kobashi, Yusuke*; Sakoda, Akihiro; Ishimori, Yuu; Yamaoka, Kiyonori*
Pakistan Journal of Zoology, 50(3), p.1157 - 1170, 2018/06
Times Cited Count：2 Percentile：17.52(Zoology)Cisplatin (CDDP) is widely used for treating solid cancers; however, it induces nephrotoxicity caused by oxidative stress. Here, we investigated whether radon inhalation has different effects against CDDP induced renal injury in two mouse strains differing in radiosensitivity, and determined the appropriate dose of CDDP combined with radon inhalation for highly radiosensitive mice. CDDP was administered at 20 mg/kg weight to C57BL/6J and BALB/c mice after radon inhalation at 1000 Bq/m and 2000 Bq/m for 24 h. Radon inhalation had a slight positive effect against CDDP toxicity in C57BL/6J mice with respect to improved hair condition, whereas radon inhalation exacerbated CDDP-induced toxicity in BALB/c mice. When BALB/c mice were treated with a lower dose of CDDP (15 mg/kg) after 1000 Bq/m radon inhalation, the creatinine level was reduced and the superoxide dismutase content was increased. The supportive effect of radon inhalation shows its good potential as a candidate treatment to alleviate CDDP-induced renal damage.
Kanzaki, Norie; Kataoka, Takahiro*; Kobashi, Yusuke*; Yunoki, Yuto*; Ishida, Tsuyoshi*; Sakoda, Akihiro; Ishimori, Yuu; Yamaoka, Kiyonori*
Radioisotopes, 67(2), p.43 - 57, 2018/02
We previously reported that low-dose radiation induces the anti-oxidative function in many organ systems of mice. This results in the suppression of several kinds of oxidative stress-induced damage. This study was conducted with the objective of revealing the health effects of low-dose radiation obtained from our previous reports and searching for a new treatment based on low-dose radiation, such as radon therapy. We extracted the characteristics of the effects of low dose radiation suppressing diseases and enhancing the anti-oxidative function using fuzzy answer by self-organizing map (SOM) based on mutual knowledge. The relationship between the suppressive effect and increased antioxidative function was shown in our result, and the concentration dependence of the effect against pain was shown on the output map. Although the effect against other organs depending on concentration was unpredictable, our results indicate that low-dose radiation may also be suitable for treatment of liver disease and brain disease.
Yamamoto, Masayoshi*; Tomita, Jumpei
Onsen Kagaku, 64(4), p.388 - 401, 2015/03
no abstracts in English
Takeda, Seiji; Kanno, Mitsuhiro; Minase, Naofumi; Kimura, Hideo
Journal of Nuclear Science and Technology, 39(8), p.929 - 937, 2002/08
no abstracts in English
Kimura, Hideo
Genshiryoku Bakkuendo Kenkyu, 8(2), p.103 - 114, 2002/03
no abstracts in English
Kimura, Hideo
KURRI-KR-56, p.95 - 108, 2001/03
no abstracts in English
Izaki, Kenji; Noda, Kimio; ; Kashimuta, Yoshio*
JNC TN8410 2001-005, 30 Pages, 2001/01
JNC-TN8410-2001-005.pdf:0.62MB
Stack monitoring is the most important work in radiation control works. Exhaust monitors used for stack monitoring have the background (which is the counts by natural radio-nuclides) on normal condition, and the values of the background vary with the facilities. Therefore, if the value of background is high, it is difficult to estimate rapidly the radioactive concentration in the exhaust. In order to estimate rapidly the radioactive concentration in exhaust, we analyzed the behavior of natural radioactivity in the facilities and examine the technique fo reducing the value of the background. As a result of the examination, we found that it is possible to estimate rapidly if we change over the monitoring point to immediately after the HEPA filters on the exhaust duct. In this reports, the analyzed results of behavior of natural radio-nuclides in the facilities and the technique for reducing the values of the background are described. To reduce the value of the background has a major effect on not only rapidly estimating the radioactive density in the exhaust but also finding the unusual things on stack monitoring.
Koarashi, Jun; Amano, Hikaru; Atarashi-Andoh, Mariko
JAERI-Research 2000-028, 24 Pages, 2000/07
JAERI-Research-2000-028.pdf:2.13MB
no abstracts in English
*; *
JNC TJ1400 2000-008, 82 Pages, 2000/03
JNC-TJ1400-2000-008.pdf:3.05MB
no abstracts in English
*
JNC TJ7420 2000-001, 14 Pages, 2000/02
JNC-TJ7420-2000-001.pdf:0.27MB
no abstracts in English
JNC TN1400 2000-001, 371 Pages, 2000/01
JNC-TN1400-2000-001.pdf:12.26MB
no abstracts in English
Rn in unsaturated soilKoarashi, Jun; Amano, Hikaru; Iida, T.*; Yamazawa, Hiromi; Nagai, Haruyasu
Proceedings of 10th International Congress of the International Radiation Protection Association (IRPA-10) (CD-ROM), 9 Pages, 2000/00
no abstracts in English
