Elucidation of the Electrostatic Charging State of Ambient Aerosols and Evaluation of Its Effect on Deposition to Body Tissue

• Project/Area Number: 17H01864
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Keio University
• Principal Investigator: Okuda Tomoaki 慶應義塾大学, 理工学部(矢上), 准教授 (30348809)
• Co-Investigator(Kenkyū-buntansha): 岩田 歩 慶應義塾大学, 理工学部(矢上), 助教 (30827340) ; 深潟 康二 慶應義塾大学, 理工学部(矢上), 教授 (80361517)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥18,200,000 (Direct Cost: ¥14,000,000、Indirect Cost: ¥4,200,000); Fiscal Year 2019: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2018: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2017: ¥9,620,000 (Direct Cost: ¥7,400,000、Indirect Cost: ¥2,220,000)
• Keywords: エアロゾル / 帯電状態 / 沈着 / 生体影響 / 電気移動度 / KPFM / PM2.5 / 粒子状物質 / 粒子帯電 / 環境分析 / 環境質定量化・予測 / 大気汚染防止・浄化 / 気象条件

Outline of Final Research Achievements

Several laboratory experiments and numerical simulations have shown that the aerosol charging state influences particle deposition on human airway surfaces. However, the actual charging state of ambient aerosol particles is still quite unknown. We try to elucidate the mechanisms of aerosol charging and its impact on the surrounding environment including human body by measuring several parameters of atmospheric aerosols through the development of original measurement methods (K-MACS: Keio-Measurement System of Aerosol Charging State). The particle charge distribution varied depending on the measurement date. The fraction of non-charged particles (10-25%) negatively correlated with volumetric humidity. A laboratory experiment supported this correlation between the aerosol charging state and volumetric humidity.

Academic Significance and Societal Importance of the Research Achievements

大気エアロゾル粒子は、呼吸によって生体内に入り込み健康に悪影響を及ぼすことが知られている。エアロゾル粒子の有害性を議論する上で把握すべき特性のうち、粒子の帯電状態については、それが粒子の生体沈着に関わるため重要性が指摘されているにも関わらず、ほとんど研究が進んでいなかった。そこで本研究では、実環境大気エアロゾル粒子の帯電状態を解明することを目的として、その計測手法の開発、年間を通じたフィールド調査、および室内実験を行った。今後は本研究で得られた粒子の帯電挙動の知見を用いて、エアロゾル粒子の帯電状態による生体への沈着挙動に対して、観測事実に基づいた確実性を加えることが可能となると期待される。

Research Products

• [Int'l Joint Research] 西安交通大学(中国)
• [Int'l Joint Research] 西安交通大学(中国)
• [Journal Article] Charging states on atmospheric aerosol particles affected by meteorological conditions (2020)
  • Author(s): He Yuanping、Gu Zhaolin、Lu Weizhen、Zhang Liyuan、Zhang Daizhou、Okuda Tomoaki、Yu Chuck Wah
  • Journal Title: Particuology Volume: 52 Pages: 1-9
  • DOI: 10.1016/j.partic.2019.12.007
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Atmospheric humidity and particle charging state on agglomeration of aerosol particles (2019)
  • Author(s): He, Y., Gu, Z., Lu, W., Zhang, L., Okuda, T., Fujioka, K., Luo, H., Yu, C.
  • Journal Title: Atmospheric Environment Volume: 197 Pages: 141-149
  • DOI: 10.1016/j.atmosenv.2018.10.035
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Numerical simulation of parallel-plate particle separator for estimation of charge distribution of PM2.5 (2019)
  • Author(s): Yonemichi, T., Fukagata, K., Fujioka, K., Okuda, T.
  • Journal Title: Aerosol Science and Technology Volume: 53 Issue: 4 Pages: 394-405
  • DOI: 10.1080/02786826.2019.1569198
  • Peer Reviewed
• [Journal Article] Seasonal variation in atmospheric particle electrostatic charging states determined using a parallel electrode plate device (2019)
  • Author(s): Iwata, A., Fujioka, K., Yonemichi, T., Fukagata, K., Kurosawa, K., Tabata, R., Kitagawa, M., Takashima, T., Okuda, T.
  • Journal Title: Atmospheric Environment Volume: 203 Pages: 62-69
  • DOI: 10.1016/j.atmosenv.2019.01.040
  • Peer Reviewed
• [Journal Article] 地下鉄構内空気中粒子状物質の特性調査 (2019)
  • Author(s): 奥田知明，坂出壮伸，藤岡謙太郎，田端凌也，黒澤景一，野村優貴，岩田歩，藤原基
  • Journal Title: 大気環境学会誌 Volume: 54 Pages: 28-33
  • NAID: 130007618321
  • Peer Reviewed / Open Access
• [Presentation] Elucidation of the relationship between the electrostatic charging state of ambient aerosols and meteorological condition by a parallel electrode plate device (2019)
  • Author(s): Ryoya Tabata, Ayumi Iwata, Kentaro Fujioka, Takuto Yonemichi, Koji Fukagata, and Tomoaki Okuda
  • Organizer: 11th Asian Aerosol Conference (Hong Kong, China)
  • Int'l Joint Research
• [Presentation] Elucidation of the Influence of Specific Meteorological Conditions on the Electrostatic Charging State of Ambient Aerosols by a Parallel Electrode Plate Device (2019)
  • Author(s): Ryoya Tabata, Ayumi Iwata, Kentaro Fujioka, Tomoaki Okuda
  • Organizer: American Association for Aerosol Research 37th Annual Conference (Portland, Oregon, USA)
  • Int'l Joint Research
• [Presentation] 平行電極板デバイスを用いた実環境大気エアロゾルの帯電状態の支配要因の解明 (2019)
  • Author(s): 田端凌也、岩田歩、藤岡謙太郎、奥田知明
  • Organizer: 第36回エアロゾル科学・技術討論会、広島大学（広島県・東広島市）
• [Presentation] Elucidation of electrostatic charging characteristics of radioactive Cs-bearing particles by Kelvin Probe Force Microscopy (2019)
  • Author(s): Kurosawa, K., Iwata, A., Satou, Y., Igarashi, Y., Abe, Y., Okuda, T.
  • Organizer: IU-IRSN/Japan-UK EICHI-project joint international workshop on radioactive particles, Mito, Japan
  • Int'l Joint Research
• [Presentation] Measurement of the electrostatic charging state of aerosol using a parallel electrode plate device (2018)
  • Author(s): Fujioka, K., Iwata, A., Tabata, R., Kurosawa, K., Yonemichi, T., Fukagata, K., Okuda, T.
  • Organizer: 10th International Aerosol Conference, St. Louis, USA
  • Int'l Joint Research
• [Presentation] Numerical simulation of a parallel-plate separator for PM2.5 (2018)
  • Author(s): Yonemichi, T., Fukagata, K., Fujioka, K., Okuda, T.
  • Organizer: 10th International Aerosol Conference, St. Louis, USA
  • Int'l Joint Research
• [Presentation] Measurement of the chemical components of aerosol particles with different electrostatic charging state (2018)
  • Author(s): Kurosawa, K., Fujioka, K., Yonemichi, T., Fukagata, K., Okuda, T.
  • Organizer: Joint International Symposium of 14th CACGP & 15th IGAC, Takamatsu, Japan
  • Int'l Joint Research
• [Presentation] Measurement of the electrostatic charging state of ambient aerosol using a parallel electrode plate device (2018)
  • Author(s): Tabata, R., Iwata, A., Fujioka, K., Kurosawa, K., Yonemichi, T., Fukagata, K., Okuda, T.
  • Organizer: Joint International Symposium of 14th CACGP & 15th IGAC, Takamatsu, Japan
  • Int'l Joint Research
• [Presentation] Numerical simulation of a parallel plate particle separator for measurement of charging state of PM2.5 (2017)
  • Author(s): Yonemichi, T., Fukagata, K., Fujioka, K., Okuda, T.
  • Organizer: 9th JSME-KSME Thermal and Fluids Engineering Conference
  • Int'l Joint Research
• [Presentation] 生体有害性に関連する微小粒子状物質の物理化学特性解明の試み (2017)
  • Author(s): 奥田知明
  • Organizer: 第34回エアロゾル科学・技術研究討論会、芝浦工業大学
  • Invited
• [Presentation] 人為的に発生させたエアロゾルの帯電状態の測定 (2017)
  • Author(s): 藤岡謙太郎、黒澤景一、北川みどり、岡久峻一、高島拓、奥田知明
  • Organizer: 第34回エアロゾル科学・技術研究討論会、芝浦工業大学
• [Presentation] 平行電極板デバイスを用いた実環境大気エアロゾルの帯電状態の測定 (2017)
  • Author(s): 藤岡謙太郎、米道卓音、深潟康二、北川みどり、岡久峻一、高島拓、奥田知明
  • Organizer: 第58回大気環境学会年会、兵庫医療大学
• [Remarks] 環境化学研究室 | 研究内容 | ハイライト【粒子の帯電状態】
  • URL: https://www.applc.keio.ac.jp/~okuda/research/theme/charge.html
• [Remarks] KEIO RESEARCH HIGHLIGHTS | Air pollution and ...
  • URL: https://research-highlights.keio.ac.jp/2019/03/b.html
• [Remarks]
  • URL: http://www.applc.keio.ac.jp/~okuda/research/index.html
• [Remarks]
  • URL: https://research-highlights.keio.ac.jp/2019/03/b.html
• [Remarks]
  • URL: http://www.applc.keio.ac.jp/~okuda/research/index.html