Okuda, Tomoaki

写真a

Affiliation

Faculty of Science and Technology, Department of Applied Chemistry ( Yagami )

Position

Professor

Related Websites

External Links

Profile Summary 【 Display / hide

  • Study on physical and chemical characteristics of atmospheric particulate matter (PM2.5) associated with health hazard

Career 【 Display / hide

  • 2020.04
    -
    Present

    理工学部応用化学科, 大学教授

  • 2023.04
    -
    Present

    理工学研究科開放環境科学専攻環境エネルギー科学専修, 専修主任

  • 2024.04
    -
    Present

    理工学部, 企画室会議

  • 2025.04
    -
    Present

    理工学部, 学習指導副主任

  • 2015.04
    -
    2020.03

    理工学部応用化学科, 大学准教授

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Academic Background 【 Display / hide

  • 1999.04
    -
    2002.03

    Tokyo University of Agriculture and Technology, Graduate School, Division of Agricltural Sciences

    Graduate School, Completed, Doctoral course

  • 1997.04
    -
    1999.03

    Tokyo Metropolitan University, Graduate School, Division of Natural Science, Department of Chemistry

    Graduate School, Completed, Master's course

  • 1993.04
    -
    1997.03

    Tokyo Metropolitan University, Faculty of Science, Department of Chemistry

    University, Graduated

Academic Degrees 【 Display / hide

  • Doctor (Agricultural Science), Tokyo University of Agriculture and Technology, Coursework, 2002.03

 

Research Areas 【 Display / hide

  • Environmental Science/Agriculture Science / Environmental dynamic analysis (Environmental Dynamic Analysis)

  • Nanotechnology/Materials / Green sustainable chemistry and environmental chemistry (Environmental Chemistry)

  • Natural Science / Space and planetary sciences (Earth Astrohemistry)

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Transport phenomena and unit operations

Research Keywords 【 Display / hide

  • aerosol, PM2.5, fine particulate matter, physical and chemical characteristics, health impacts

 

Books 【 Display / hide

  • 環境化学

    OKUDA TOMOAKI, 日本有機地球化学会, 2014

    Scope: 日本地球化学会(監修)地球・環境有機分子質量分析マニュアル2014,第1部第5章

  • Aerosol Pollution in China

    OKUDA TOMOAKI, TANAKA SHIGERU, HE KEBIN, MA YONGLIANG, 京都大学学術出版会、京都, 2007

    Scope: 24-32

Papers 【 Display / hide

  • Variability of submicron ice-nucleating particles at urban and rural sites in Japan related to aerosol chemical components

    Iwata A., Horwitz S.G.M., Kurihara K., Matsuki A., Okuda T.

    Atmospheric Research 327 2026.01

    ISSN  01698095

     View Summary

    Ice-nucleating particles (INPs) play a pivotal role in cloud formation and precipitation, yet predicting their concentrations remains difficult due to limited understanding of their spatiotemporal variability and characteristics. Therefore, it is important to provide insights into how aerosol properties and meteorological parameters are related to INP concentrations. This study investigated INP concentrations, their heat sensitivity, particle chemical components, and meteorological parameters at urban (Yokohama) and rural (Noto) sites in Japan during Dust and Non-Dust periods. While no single key factor consistently explained INP concentrations, relatively strong associations were observed with factors implying particles such as mineral dust, heat-sensitive biological particles, and Pb-containing particles from coal and waste combustion, with variations depending on site and season. During the Dust period, INP concentrations at both sites were correlated with the mineral indicators (R > 0.57), though INPs above −15 °C remained low at Noto site (R = 0.49). In the Non-Dust period, mineral indicators cannot account for INP levels at either site (R < −0.31). Heat treatment-induced deactivation of INPs above −15 °C in the urban area suggested a close association between biological INPs and mineral particles. Although submicron INPs account for only a small fraction of total INPs at the surface (e.g., < 6.5 % at −12.5 °C), the particle types that contributed to the variability in INP concentrations were nevertheless supported previous qualitative findings. Our findings also highlight the complexity of quantitatively linking environmental factors that vary by region and time to INP concentration variations to characterize aerosol–cloud interactions.

  • Development of a Water-Soluble Filter for Potential Use in the Toxicity Evaluation of Ambient Particulate Matter

    Yang, L; Nishita-Hara, C; Shiraishi, M; Tsubakida, K; Shibata, Y; Jing, WD; Li, D; Yoshimura, K; Kurokawa, N; Hotta, A; Okuda, T

    AEROSOL AND AIR QUALITY RESEARCH 26 ( 1 )  2025.12

    ISSN  1680-8584

  • Numerical analysis of collision mechanism that causes particle tribocharging in dry powder inhaler

    Mitani R., Nor M.A.b.M., Iinuma T., Mori T., Okuda T.

    Asian Journal of Atmospheric Environment 19 ( 1 )  2025.12

    ISSN  19766912

     View Summary

    Chronic obstructive pulmonary disease (COPD) is induced by inhalation of toxic substances such as cigarettes and air pollution. Dry powder inhalers (DPIs) are the primary treatment for these diseases. However, they have some problems, such as residuals in a capsule caused by electrostatic force before reaching the human lungs. This study investigated the particle tribocharging mechanism in a DPI using a tandem differential mobility analyzer (TDMA) and a combined discrete element method and computational fluid dynamics (DEM-CFD) approach. In the TDMA experiment, the charging state of the particles changed from negative to positive charge in the DPI device fabricated by the 3D printer. This is because tribocharging is caused by particle–particle collisions and particle–wall collisions. In the numerical simulation, particle–wall collisions occurred more frequently than particle–particle collisions. Therefore, the particle–wall collisions change the charging state of the particle in the DPI device. These results suggest that collisions between particles and walls of the device cause the particles to become charged, leading to a decrease in their deposition in the deeper regions of the lungs. Moreover, the large turbulence kinetic energy of the airflow in the DPI device caused particle–wall collisions because the particles were widely dispersed in the DPI device. These results suggest that optimum turbulence kinetic energy is necessary to reduce particle aggregation and improve the delivery efficiency of DPIs to the human lungs.

  • Comparative analysis of polycyclic aromatic sulfur heterocycles (PASHs) in PM2.5 from Xi’an, China and Yokohama, Japan: pollution characteristics and source attribution

    Chen K., Jing W., Shen Z., Okuda T.

    Asian Journal of Atmospheric Environment 19 ( 1 )  2025.12

    ISSN  19766912

     View Summary

    Polycyclic aromatic sulfur heterocycles (PASHs) sulfur-containing analogues of polycyclic aromatic hydrocarbons (PAHs) are emerging atmospheric pollutants of concern due to their potential toxicity and environmental persistence. This study presents the first comparative analysis of PASHs in PM<inf>2.5</inf> between two representative East Asian cities: Xi’an, China, and Yokohama, Japan. Ambient PM<inf>2.5</inf> samples were collected from July 2022 to July 2023, and four PASHs compounds were quantified using gas chromatography tandem mass spectrometry (GC–MS/MS). Concentrations, seasonal variations, and emission sources were systematically analyzed. The results showed that the annual mean PASHs concentration in Xi’an (156.6 pg/mg) was significantly higher than that in Yokohama (102.6 pg/mg). Source apportionment using the Positive Matrix Factorization (PMF) model identified four major pollution sources in each city, revealing notable differences in source composition between the two countries. This study advances the understanding of the atmospheric behavior and origins of PASHs in East Asian urban environments and highlights cross-regional differences in their pollution profiles.

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Papers, etc., Registered in KOARA 【 Display / hide

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Reviews, Commentaries, etc. 【 Display / hide

  • 環境大気エアロゾルの帯電状態測定の現状と展望

    奥田 知明

    クリーンテクノロジー 27 ( 4 ) 37 - 40 2017.06

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work

  • 連載 エアロゾル基礎講座 ―計測― 6. 分級②:慣性運動や遠心力を用いた分級

    奥田知明, 榎原研正, 飯田健次郎

    エアロゾル研究 (日本エアロゾル学会)  32 ( 4 ) 276 - 288 2017.12

    Article, review, commentary, editorial, etc. (scientific journal), Joint Work

  • A simple air–liquid interface exposure system for exposing cultured human 3D epidermis and cornea to PM2.5 collected through cyclonic separation

    Kono M., Takaishi M., Okuda T., Fujihara M., Noguchi S., Ishihara Y.

    Journal of Toxicological Sciences (Journal of Toxicological Sciences)  49 ( 2 ) 61 - 68 2024

    ISSN  03881350

     View Summary

    Particulate matter (PM) is among the major air pollutants suspended in the atmosphere. PM2.5 has a particle size of 2.5 µm; it is known to cause inflammation, especially in the respiratory tract and skin. Since the skin acts a primary barrier against harmful environmental substances that may enter the body, it is highly exposed to PM2.5 present in the environment. However, the adverse health effects of PM2.5 exposure on human skin have not been accurately examined due to the lack of a system that expos-es human epidermal tissue to the actual environmental concentration of PM2.5. In this study, we developed an air–liquid interface exposure system for exposing cultured human 3D epidermis and cornea to PM2.5 collected through cyclonic separation. PM2.5 suspension was nebulized in an acrylic chamber, and the resulting mist was pumped through a diffusion dryer into a glass exposure chamber. A particle counter was connected to the exposure chamber to continuously measure the spatial mass concentration of PM. Human 3D epidermis was cultured in the exposure chamber. Exposure of the human 3D epidermis to PM aerosol increased interleukin-8 release into the media around 50 µg/m3. Mass concentrations above 100 µg/m3 caused cell death. Furthermore, a human corneal model showed similar responses against PM2.5 exposure as 3D epidermis. The air–liquid interface exposure system developed in this study is considered useful for evaluating the health effects induced by environmental PM2.5 and can be used as an alternative to experiments involving actual human or animals.

  • 環境大気中PM2.5の比表面積の測定

    奥田知明

    クリーンテクノロジー (日本工業出版(株))  25 ( 6 ) 23 - 26 2015.06

    Article, review, commentary, editorial, etc. (scientific journal), Single Work

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Presentations 【 Display / hide

  • PM2.5の物理化学特性の解明と曝露実験による生体有害性評価

    奥田知明

    [Domestic presentation]  第88回日本衛生学会 (東京工科大学蒲田キャンパス、東京都大田区) , 

    2018.03

    Oral presentation (invited, special), 日本衛生学会

  • Development of measurement techniques of physical and chemical characteristics of atmospheric aerosols related to their adverse health effect

    Okuda, T.

    [International presentation]  Frontiers of Atmospheric Aerosol Studies: Toward the Understanding of Their Health and Climatic Effects (Nagoya, Japan) , 

    2018.01

    Oral presentation (invited, special)

  • Numerical simulation of a parallel plate particle separator for measurement of charging state of PM2.5

    Yonemichi, T., Fukagata, K., Fujioka, K., Okuda, T.

    [International presentation]  9th JSME-KSME Thermal and Fluids Engineering Conference (Okinawa, Japan) , 

    2017.10

    Poster presentation, JSME

  • PM2.5を集めて測る ~捕集と特性解明の技術~

    奥田知明

    [Domestic presentation]  第7回CSJ化学フェスタ (タワーホール船堀、東京都江戸川区) , 

    2017.10

    Oral presentation (invited, special), 日本化学会

  • 黄砂・PM2.5の健康乳幼児の目・鼻・呼吸器症状への影響 - エコチル調査追加調査『黄砂と子どもの健康調査(パート2)』より -

    金谷久美子、亀田貴之、大久保綾乃、森育子、増本年男、黒沢洋一、大西一成、奥田知明、中山健夫

    [Domestic presentation]  第58回大気環境学会年会 (兵庫医療大学、兵庫県神戸市) , 

    2017.09

    Poster presentation, 大気環境学会

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • Development of a novel water-soluble filter that expands the possibilities of pathogen testing methods

    2025.06
    -
    2028.03

    挑戦的研究(萌芽), Principal investigator

  • Establishment of a new environmental chemical analysis method for endotoxin as a key parameter to elucidate the toxicity of aerosol particles

    2024.04
    -
    2027.03

    基盤研究(B), Principal investigator

  • Development of a Health Effect Evaluation System for Particulate Matter Characteristics for the Central Asian Region

    2023.09
    -
    2027.03

    国際共同研究加速基金(海外連携研究), Principal investigator

  • Development and practical application of a new filter to promote collaboration between the chemical and biological research fields of aerosol toxicity assessment

    2022.06
    -
    2025.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, 挑戦的研究(萌芽), Principal investigator

  • Evaluation of the influence of charging state of atmospheric aerosol on particle deposition on human body and ground surface

    2020.04
    -
    2024.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (A) , Principal investigator

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Intellectual Property Rights, etc. 【 Display / hide

  • 微小粒子の捕集装置

    Date applied: 特願2017-132547  2017.07 

    Date announced: 特開2018-023970  2018.02 

    Patent, Joint

  • 自動オープンクロマトグラフィー装置

    Date applied:   2007.07 

    Date announced:   2007.09 

    Date issued: 3135990 

    Utility model, Joint

Awards 【 Display / hide

  • 2015 Asian Young Aerosol Scientist Award

    Tomoaki OKUDA, 2015.06, The Asian Aerosol Research Assembly, Outstanding contribution to aerosol science and technology in Asia

    Type of Award: International academic award (Japan or overseas)

  • 2023 Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology

    Tomoaki OKUDA, and 4 other members, 2023.04, Ministry of Education, Culture, Sports, Science and Technology , Contributions to the mass-gathering event under the COVID-19 pandemic

    Type of Award: International academic award (Japan or overseas)

  • Academic Award, Japan Society for Atmospheric Environment

    Tomoaki OKUDA, 2025.09, Japan Society for Atmospheric Environment, Experimental Research and Contribution to Society Regarding Atmospheric Environment and Human Health

    Type of Award: Award from Japanese society, conference, symposium, etc.

  • Best Paper Award, Japan Society for Atmospheric Environment

    Tomoaki OKUDA, Masanobu SAKAIDE, Ayumi IWATA, Motoi FUJIWARA, 2020.09, Japan Society for Atmospheric Environment, Investigation of the Characteristics of Particulate Matter Suspended in a Subway Station Platform

    Type of Award: Award from Japanese society, conference, symposium, etc.

  • Incentive Award 2015, Japan Association of Aerosol Science and Technology

    Tomoaki OKUDA, 2015.06, Japan Association of Aerosol Science and Technology, Elucidation of physical and chemical characteristics of atmospheric aerosols related to their adverse health effect

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Courses Taught 【 Display / hide

  • SEMINAR IN APPLIED CHEMISTRY

    2025

  • PROJECT FOR MULTIDISCIPLINARY AND INTERDISCIPLINARY KNOWLEDGE (SUSTAINABLE ENVIRONMENT)

    2025

  • OFF-CAMPUS WORK-STUDY PROGRAM

    2025

  • LABORATORIES IN APPLIED CHEMISTRY C

    2025

  • INTRODUCTION OF ENVIRONMENTAL CHEMISTRY

    2025

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Courses Previously Taught 【 Display / hide

  • 自然科学実験(化学)

    Keio University

    2018.04
    -
    2019.03

    Spring Semester, Laboratory work/practical work/exercise, Within own faculty

  • 大気環境科学

    Keio University

    2018.04
    -
    2019.03

    Autumn Semester, Lecture

  • 化学B

    Keio University

    2018.04
    -
    2019.03

    Autumn Semester, Lecture

  • 環境化学2

    Keio University

    2018.04
    -
    2019.03

    Autumn Semester, Lecture

  • 応用化学実験CD

    Keio University

    2018.04
    -
    2019.03

    Autumn Semester, Laboratory work/practical work/exercise, Within own faculty

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Memberships in Academic Societies 【 Display / hide

  • The Chemical Society of Japan, 

    2015.06
    -
    Present
  • Japan Association of Aerosol Science and Technology, 

    2006.04
    -
    Present
  • The Japan Society for Analytical Chemistry, 

    2004.04
    -
    Present
  • 日本大気化学会, 

    2002.04
    -
    Present
  • Japan Society for Atmospheric Environment, 

    2002.04
    -
    Present

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Committee Experiences 【 Display / hide

  • 2023.03
    -
    Present

    南極環境実態把握モニタリング事業検討委員会委員, 環境省

  • 2022.08
    -
    Present

    常任理事, 日本エアロゾル学会

  • 2020.09
    -
    Present

    常任理事, 大気環境学会

  • 2020.06
    -
    2021.03

    新型コロナウイルス対策専門家会議委員, 内閣府

  • 2019.04
    -
    Present

    環境安全推進委員会委員長, 日本化学会

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