Analysis of the toxicity-weighted release amount ranking of PRTR chemicals in Japan

Abstract

In this study, toxicity data were first collected for 184 chemicals from reliable information sources. After a validity check and analysis of these data, reference concentrations (RfC) were determined. The toxicity-weighted release amount (TWR) was then calculated for each chemical by dividing the release amounts by the RfC. Three types of TWR were derived, namely TWR_atm for human health protection in the atmosphere, TWR_wat for human health protection in water, and TWR_aq for aquatic life protection. Thus, TWR could be proposed as a new index for environmental risk management considering both toxicity and release amount. Based on the TWR values, chemicals were ranked according to their potential risk upon release. The ranking results revealed that acrolein, formaldehyde, 1,3-butadiene, and arsenic are among the substances with the greatest risk to human health protection in the atmosphere; acrylonitrile, hydrazine, and pyridine are among those detrimental to human health protection in water; and polyoxyethylene alkyl ether (POAE), n-alkylbenzene sulfonic acid (LAS), and N,N-dimethyldodecylamine N-oxide are those identified as posing a risk to aquatic life protection. Moreover, for higher TWR chemicals, the contribution of each release source has been analyzed and discussed. For example, POAE and LAS are released mainly from households, and therefore efforts to reduce their concentration in the environment should focus on the sewage system. Formaldehyde and 1,3-butadiene are mainly emitted from mobile sources and, therefore, traffic should be evaluated as an important release source of toxic chemicals besides many stationary sources. Acrylonitrile and arsenic are released mainly by a few specific industries, placing the emphasis on the need for responsible care by the individual companies involved.

Keywords:

• Pollutant release and transfer register (PRTR)
• toxicity-weighted release
• potential risk
• reference concentration

Acknowledgments

This work was supported in part by a Grant-in-Aid for Exploratory Research of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.

This paperwas presented at the SETACAsia/Paciic 2006 conference held at Peking University, China on September 18-20, 2006.

Notes

* The chemical of rank-X is a chemical from which TWR is not calculated, because there is no toxicity value.

¹ Report required establishments including designated 22 industries.

² Non-reporting small establishments in designated 22 industries.

³ Non-designated industries such as agriculture.

⁴ Mobile bodies such as car.

¹ Report required establishments including designated 22 industries.

² Non-reporting small establishments in designated 22 industries.

³ Non-designated industries such as agriculture.

¹ Report required establishments including designated 22 industries.

² Non-reporting small establishments in designated 22 industries.

³ Non-designated industries such as agriculture.