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Battulga, B.; Atarashi-Andoh, Mariko; Matsueda, Makoto; Koarashi, Jun
Environmental Science and Pollution Research, 30(31), p.77226 - 77237, 2023/05
Times Cited Count：0 Percentile：0(Environmental Sciences)The global survey for the presence of microplastics (MPs) in aquatic environments has attracted widespread scientific attention over the past decade. This study demonstrates a multidimensional analytical approach, including isotopic and thermogravimetric analyses to evaluate characteristics and behavior of MPs in the environment. The MP samples were collected in two contrasting coastal areas of Japan. The 
C values of field-collected polyethylene (PE), polypropylene (PP), and polystyrene (PS) MPs were ranged from -25.6 to -31.4, -23.4 to -30.9, and -27.3 to -28.6 per mil, respectively. The differences in C signature between MPs with the same polymer types (i.e., PE and PP) but different colors. Through thermal analysis, the single-step endothermic process was observed for environmental PE and PS-MPs. The results reveal that degradation may play a significant role in the behavior and characteristics of MP debris in the aquatic environment.
Battulga, B.; Atarashi-Andoh, Mariko; Nakanishi, Takahiro; Koarashi, Jun
Science of the Total Environment, 849, p.157758_1 - 157758_11, 2022/11
Times Cited Count：3 Percentile：40.21(Environmental Sciences)Characterizing plastic-associated biofilms is key to the better understanding of organic material and mineral cycling in the "Plastisphere"-the thin layer of microbial life on plastics. In this study, we propose a new method to extract biofilms from environmental plastics, in order to evaluate the properties of biofilm-derived organic matter through stable carbon (C) and nitrogen (
N) isotope signatures and their interactions with radionuclides especially radiocesium (
Cs). After ultrasound-assisted separation from the plastics, biofilm samples were successfully collected via a sequence of syringe treatments. Biofilm-derived organic matter samples (14.5-65.4 mg) from four river mouths in Japan showed Cs activity concentrations of 
75 to 820 Bq kg
biofilm (dw), providing evidence that environmental plastics, mediated by developed biofilms, serve as a carrier for Cs in the coastal environment. Significant differences in the (C and N signatures were also obtained for the biofilms, indicating the different sources, pathways, and development processes of biofilms on plastics.
Nakamura, Shoji; Kimura, Atsushi; Hales, B. P.; Iwamoto, Osamu; Shibahara, Yuji*; Uehara, Akihiro*; Fujii, Toshiyuki*
JAEA-Conf 2018-001, p.199 - 203, 2018/12
Study on cross-section measurements has been promoted for 
Cs among long-lived fission products in ImPACT Project. The feasibility study on 
Se sample preparation also has been conducted to measure its cross sections in future. During the feasibility study, we started the neutron-capture cross-section measurements of stable Se isotopes. This paper reports research progresses on preparation of a radioactive Cs sample, neutron irradiation experiments with the Cs sample, and cross-section measurements of stable Se isotopes.
Nakashio, Nobuyuki; Isobe, Motoyasu; Wakui, Takuji*; Iwata, Keiji*; Kibayashi, Tatsuyuki*; Kanazawa, Katsuo; Fukui, Toshiki; Otake, Atsushi*; Nakashima, Mikio; Hirabayashi, Takakuni*
JAERI-Research 2001-001, 19 Pages, 2001/02
JAERI-Research-2001-001.pdf:1.29MB
no abstracts in English
Otsubo, Takashi*; Oya, Susumu*; Goto, Jun*; *; Muto, Suguru*; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki
JAERI-Review 99-025, TIARA Annual Report 1998, p.206 - 207, 1999/10
no abstracts in English
*; *; *; *; *; *; *; Muto, Suguru*; Osa, Akihiko; Koizumi, Mitsuo; et al.
Hyperfine Interactions, 120-121(1-4), p.695 - 699, 1999/00
no abstracts in English
Sekine, Toshiaki; Ichikawa, Shinichi; Osa, Akihiko; Koizumi, Mitsuo; Iimura, Hideki; Tsukada, Kazuaki; Nishinaka, Ichiro; Hatsukawa, Yuichi; Nagame, Yuichiro; Asai, Masato*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 239(1), p.127 - 131, 1999/00
Times Cited Count：2 Percentile：21.16(Chemistry, Analytical)no abstracts in English
Koizumi, Mitsuo; Osa, Akihiko; Sekine, Toshiaki; *
"Fuanteikaku No Rikogaku Oyobi Kaku Keisokuho(II)" Ni Kansuru Semmon Kenkyukai Hokokusho, 0, p.54 - 57, 1997/00
no abstracts in English
states in 
BaAsai, Masato*; *; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki; *; Yamamoto, Hiroshi*; Kawade, Kiyoshi*
"Fuanteikaku No Rikogaku Oyobi Kaku Keisokuho(II)" Ni Kansuru Semmon Kenkyukai Hokokusho, 0, p.97 - 100, 1997/00
no abstracts in English
Sekine, Toshiaki; Koizumi, Mitsuo; Osa, Akihiko
KURRI-KR-3, 0, p.13 - 17, 1996/00
no abstracts in English
Asai, Masato*; *; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki; *; Yamamoto, Hiroshi*; Kawade, Kiyoshi*
KURRI-KR-3, 0, p.36 - 40, 1996/00
no abstracts in English
Nishimura, Akihiko; Shibata, Takemasa
Journal of Nuclear Science and Technology, 32(9), p.905 - 911, 1995/09
Times Cited Count：2 Percentile：28.04(Nuclear Science & Technology)no abstracts in English
Sekine, Toshiaki; ;
KURRI-TR-348, p.42 - 44, 1991/04
no abstracts in English
Cr; ; Motoki, Ryozo; Yamamoto, Takeo; Nishida, Hiroshi*; Shin, Sumio*; Sato, Kiichi*; *
Radioisotopes, 34(3), p.144 - 150, 1985/00
no abstracts in English
CrShin, Sumio*; ; *; Nishida, Hiroshi*; ; ; Motoki, Ryozo
Igaku No Ayumi, 130(6-7), p.437 - 439, 1984/00
no abstracts in English
Tsuchiya, Kunihiko
no journal, ,
no abstracts in English
Battulga, B.; Atarashi-Andoh, Mariko; Koarashi, Jun
no journal, ,
Plastic debris has been recognized as one of the carriers of hazardous substances in the aquatic ecosystem due to its ubiquitous distribution and potential interaction with pollutants through developed biofilms. In this study, we aimed to extract biofilms from the environmental plastics using a newly developed extraction method and to determine the concentration of radiocesium (Cs) and stable isotope ratios (C and N) in the extracted biofilm samples. Visible plastics were collected from the mouths of coastal rivers in Ibaraki prefecture, Japan, and applied to the extraction procedures. After plastic and biofilm separation with ultrasonication, biofilm samples were collected by the two ways: freeze-drying (15.5-44.4 mg); and freeze-drying after syringe treatment (14.5-65.4 mg). The XRD diffractograms of biofilm samples confirmed that biofilms obtained by freeze-drying only were still heterogeneous and the agglomerations of organic substances, mineral particles, and small microplastics (MPs, 1 mm). The results also demonstrated that biofilm extraction was achieved by syringe treatment separating the mineral and small MPs particles, resulting in homogenous biofilms from the surface of plastics. Preliminarily results of Cs activity concentrations in heterogenous (ranging from 0.22 to 0.54 Bq g) and homogenous (0.82
0.04 Bq g) biofilm samples revealed that MPs serve as a carrier for Cs in the coastal river environment mediated by developed biofilms.
Battulga, B.; Nakayama, Masataka; Atarashi-Andoh, Mariko; Koarashi, Jun
no journal, ,
Plastic debris in the aquatic environment has become a growing concern due to their long-term ecological consequences. The current study is focused on microbial community composition on microplastics (MPs; sizes 5 mm) and characteristics of MP-associated biofilms in coastal river environments of Japan in order to understand the impact of MP-associated biofilms on aquatic organic matter cycling. The aims of the current study are i) extraction and characterization of microbial biofilms on MPs and ii) identification of diversity and composition of microbial communities on MP surfaces and in surrounding surface waters and sediments. The samples were collected from two coastal rivers during 2021-2022 on a seasonal basis. In this study, we proposed a new method to extract biofilms from MPs using ultrasound-assisted syringe treatment for isotopic analysis. Morphotypes of MPs and associated specific microbial taxa as well as seasonal differences were also observed.
Battulga, B.; Nakanishi, Takahiro; Atarashi-Andoh, Mariko; Koarashi, Jun
no journal, ,
Plastic debris in the aquatic environment receives special attention from scientific communities, whereas the radioactivity of environmental plastic and the dynamics of plastic-associated biofilm remain largely unknown. In this study, we addressed plastic-associated biofilms and bottom sediments from two contrasting coastal areas of Japan to elucidate their characteristics and interaction with radionuclides especially radiocesium (Cs) in the environment. We also explored stable isotope (C and N) signatures of the biofilm and sediment samples based on seasonal variations. Trace of Cs was observed in biofilm with an activity concentration of 29219.4 Bq kg biofilm (dw) which correspond to 1.150.08 Bq kg plastic (dw).
