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  • Environmental Exposure Modeling Group
  • Environmental Exposure Modeling Group

    Environmental Exposure Modeling Group

    Hideo Kajihara
    Group Leader:Hideo Kajihara

    5 Researchers:
     Yuriko Ishikawa, Kazuya Inoue, Tomoko Oguri, Hiroo Hata

    6 Contract Employees


    We are developing environmental exposure modeling technology, which is important for assessing the risk of chemical substances to humans and ecosystems. Environmental exposure modeling is a technology that makes it possible to clarify the actual conditions of exposure to humans and ecosystems from the environment by formulating the components and their interrelationships, and to estimate the concentration and exposure amount without actual measurement. Environmental exposure modeling can make effective risk reduction proposals. The goal is to be used not only in the government, such as in compliance with the Chemical Substances Control Law and the Chemical Substances Control Law, but also in the SDGs and responsive care of private companies through technical consultation, consulting, and joint research.

    Research Highlights

    Development and application of atmospheric models

    Development of ADMER (Atmospheric Dispersion Model for Exposure and Risk assessment) & ADMER-PRO
    • Estimate atmospheric concentrations and population exposure to chemical substances with high spatial and temporal resolution.
    • Models can be easily operated on a standard Windows PCs.
    • Models contains required input data, so concentration distributions and reduction potentials can be estimated with little time and effort.


    Display example of ozone concentration distribution in ADMER-PRO


    Their application to chemical risk assessment & management
    • In addition to the above atmospheric models, we have developed the “Air Pollution Countermeasure Benefit Evaluation Tool” and other tools to consistently estimate the benefits of various environmental and energy countermeasures
    • Contributing to the advancement of chemical substance management based on cost-benefit analysis



    Atmospheric modeling via chemical kinetics

    Chemical kinetics and chemical transport model
    • Evaluating the rate constants of atmospheric chemical reactions by spectroscopical experiments and quantum chemistry calculation.
    • Incorporation of the chemical kinetic parameters to regional and global chemical transport models.
    • Health risk evaluation for the scenario of the introduction of next generation technologies by the chemical transport models.


    Change of PM2.5 concentration by incorporating new kinetic parameters.

    River and coastal modeling

    SHANEL (Standardized Hydrology-based Assessment tool for chemical Exposure Load)
    • Estimation of spatial distributions and temporal changes of chemical concentration in rivers nationwide.
    • Exposure assessment of chemicals in rivers by life and industrial activities or leakage accidents.
    • Set data on watershed information.
    • Improving the model to apply to marine biodegradable plastics.


    Example of concentration distribution in river water


    RAM-TB (Risk Assessment Model – Tokyo Bay)
    • Spatial-temporal analysis of concentrations of chemical substances in coastal water.
    • Ecological risk assessment by load in coast, air and rivers and simple physical properties.
    • Set data on ocean currents and nutrients for the target coastal area.
    • Improving the model to apply to marine biodegradable plastics.


    Output display of concentration distribution in Tokyo Bay

    Exposure assessment of consumer products

    ICET (Indoor Consumer Exposure assessment Tool)
    • Can be applied to chemical substances for various purposes such as insect repellents, plasticizers, solvents, flame retardants, etc.
    • Can handle droplets with a spray model.


    Example of exposure scenario


    Characterization of products group into which marine biodegradable plastics may be introduced
    • In order to estimate the effect of reducing marine plastic waste by introducing marine biodegradable plastic, we are characterizing products into which marine biodegradable plastics may be introduced

    Assessing human exposure of individuals

    Development of Pharmacokinetic and Exposure Reconstruction Models for Chemicals substance
    • Build a pharmacokinetic and exposure reconstruction models that links the concentration in biological sample by human biomonitoring and the estimated exposure amount via environmental media
    • Contribute to advanced exposure assessment and chemical management


    Conceptual diagram of Pharmacokinetic and Exposure Reconstruction Models