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  • Risk Assessment Strategy Group

    Risk Assessment Strategy Group

    Wataru Naito
    Group Leader:Wataru Naito

    8 Researchers:
     Katsuhide Fujita, Yuichi Iwasaki, Masashi Kamo, Hiroyuki Mano, Naohide Shinohara, Jun-ichi Takeshita,  
     Akihiro Moriyama

    10 Contract Employees


    We are conducting risk assessment research on chemicals (including microplastics), nanomaterials, and SARS-Cov-2 viruses. Specifically, we develop methods for risk assessment necessary for promoting innovation of new materials such as nanomaterials, develop methods for obtaining missing data for risk assessment, evaluate risks in actual environments, and promote pragmatic risk assessment for solving social issues. Our goal is to contribute to the realization of a sustainable society where industry and the environment coexist.

    Research Highlights

    Methods for Risk Assessment and Management of Chemicals

    Development of Toxicity Prediction Methods for  Rapid and Efficient Risk Assessments

    • Development of mathematical science-based toxicity prediction methods for human health and ecological risk assessment
    • Development of a prediction method for Species Sensitivity Distribution (SSD) for quantitative ecological risk assessment


    Development of Combined Toxicity and Population-Level Assessment Methods Using Mathematical Models

    • Development of models, statistical test theories, and combinatorial optimization methods for assessing the combined exposure effects of chemicals
    • Development of assessment methods for population-level ecological risk of chemicals

    An illustration of population-level impact due to hazardous chemical exposure


    Pragmatic Risk Assessment of Freshwater and Marine Environments

    • Prediction and evaluation of ecological effects in natural environments based on results of field surveys.
    • Performing practical environmental risk assessments considering regional characteristics using field measurements and modeling techniques.

    Sampling at river

    Risk Assessment and  Management Using Bioassays

    • Evaluation of ecological effects on natural environments from living organism response to environment water.
    • Investigation of methods for reducing impacts of wastewater at workplaces.

    Devices and species for bioassay

    Environmental risk assessment of microplastics (MP)

    • Identification of research gaps necessary for environmental risk assessment of MPs and considerations in risk assessment
    • Illustration of the procedures for environmental risk assessment of MPs and conduct  trial risk assessment of MPs


    Indoor Exposure Assessment

    • Measurement of emission and adsorption rates of SVOCs in the laboratory and actual environment contributing to elucidation of indoor behaviors of chemical substances and improvement of exposure risk assessment and measurement of dermal exposure.
    • Investigation of indoor mold, mite and endotoxin. Assessment of indoor ventilation and particle behavior.

    Measurements in Indoor Environment


    Methods for Testing Toxicity of Nanomaterials
    (Carbon nanomaterials, Metal nanoparticles, Cellulose Nanofibers)

    Standardization and Publication of Simple Safety Testing Methods of Nanomaterials

    • Publication of procedural manuals aiming for the standardization of toxicity test methods such as the intratracheal instillation test and in vitro cell-based assay supporting voluntary management of new technologies by companies.


    Development of Toxicity Assessment Methods of Cellulose Nanofibers (CNFs)

    • Conduct safety assessments for a variety of CNF products.
    • Development of simple toxicity test methods (cell test, intratracheal installation test, ecotoxicity test, etc.) that companies can implement on their own.
    • Publication of a procedure manual

    TEM image of CNFs


    Measurement and Estimation of exposure parameters for assessing risk of COVID-19 infection in public transportation and mass-gathering events

    • Measurement and estimation of ventilation and particle behavior in actual public transportation vehicles, etc.
    • Monitoring CO2 concentrations in outdoor and indoor environments in stadiums
    • Visualization and quantification of droplets and droplet nuclei using an exhalation and cough simulator