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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

    4 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

    The scope of the environmental exposure modeling

    • Development of exposure modeling technology for humans and ecosystems from various environmental media (air, water, indoor, products, foods).
    • Development of software and measurement technology for exposure assessment.

    Targets a wide range of environmental exposures such as air, water, indoor, products, and foods


    Atmospheric modeling

    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.
    • ADMER-PRO can also be applied to secondary products such as ozone.

    Display example of ozone concentration distribution in ADMER-PRO


    Sophistication of risk evaluation accuracy by incorporating newly found chemical mechanisms to the chemical transport model


    Explore the new chemical pathways of PM2.5 generation from the experiments.

    Incorporating the new chemical reactions from experiments to the chemical transport model (CTM) and enhancing the performance of model prediction.

    Appling the modified CTM to the risk evaluation: e.g., effect of the introduction of carbon-free technologies to the atmosphere and human health.

    Effect of newly found chemical reactions to PM2.5 conc.


    Exposure modeling in the environment around and inside a person

    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.

    Can also be used by companies and government agencies.

    Example of exposure scenario


    Development of exposure reverse estimation model construction system


    Build a reverse exposure estimation model that links the in vivo concentration by bio-monitoring and the exposure amount by environmental monitoring.

    Contribute to advanced exposure assessment and chemical management.



    River and coastal modeling

    (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 chemical substances in rivers discharged by life and industrial activities or spilled by leakage accidents.
    • Built-in river basin data.
    • 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.
    • Built-in physical quantity and ecosystem data for the target coastal area.
    • Ecological risk assessment by lineal and point source load in coast, air and rivers and simple physical properties.
    • Improving the model to apply to marine biodegradable plastics.

    Output display of concentration

    distribution in Tokyo Bay