"Exposure and Risk Assessment of Hazardous Air Pollutants in Japan" 

Haruyuki Higashino, Hiroshi Yoshikado, Yoshitaka Yonezawa, Junko Nakanishi

National Institute of Advanced Industrial Science and Technology      

SRA 2005 Annual Meeting (Orlando, Florida, U.S.A.. 2005/12/6)

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Abstract

We assessed the risks and consequences of exposure to hazardous air pollutants for human health and have published the results as an exposure and risk assessment document that provides a scientific basis for the decision-making process of regulatory bodies with regard to chemical risk management in the national government. Target substances for the assessment include 11 chemicals which are on the list of Substances Requiring Priority Action published by the Central Environmental Council of Japan in 1996. Emission of these substances has been controlled by the responsible care program since 1997. Because the total emissions of these substances have decreased in Japan in recent years, primarily because of reductions related to responsible care in industry, we should evaluate the outcomes of the program. The remarkable advantage of our method of risk assessment is a detailed exposure assessment. We have developed two different types of models to assess exposure: AIST-ADMER estimates regional concentration distributions, while METI-LIS estimates concentration distributions around factories. Both models were used for the exposure assessment. The risks of exposure to chemicals were evaluated by comparing estimated ambient concentrations with reference concentrations. Reference concentrations were selected by environmental standards for target substances when available, and were determined by surveying the literature concerning current toxicity when the environmental standards were not available. Our results indicate that areas where stationary emissions dominate are very limited for many substances and that emissions not only from the nearest large point source but also from smaller sources in an area contribute to high concentrations, even near large point sources; as such, the responsible care program for industrial stationary sources should be revised.

Keywords

Exposure, Risk, ADMER, METI-LIS, Hazardous air pollutants