"Risk assessment and management of chloroform in Japan" 

Yuriko Ishikawa, Hajime Kawasaki, Takehiko Hayashi 

National Institute of Advanced Industrial Science and Technology

Society for Risk Analysis 2006 Annual Meeting (Baltimore 2006/12/4)

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Abstract

We performed risk assessment of chloroform in Japan and proposed the risk reduction measures. Significant releases of chloroform to the environment occur indirectly through reactions of chlorine with organic chemicals and as by-products during the addition of chlorine to drinking water and wastewaters for disinfection. Therefore, we estimated the emission amounts and exposures of chloroform released not only directly but also indirectly as disinfectant by-products through chlorination of water and paper bleaching with chlorine. Most of environmental releases of chloroform are to the atmosphere. Chloroform released to surface waters or soil will be transported to the air because of its high volatility. In Japan chloroform has been observed in ambient air and indoor air frequently, whereas in surface water and groundwater chloroform has been rarely observed. The general population in Japan is exposed to chloroform principally through inhalation of indoor air and ingestion of tap water. We estimated intake from daily showering, bathing and swimming in the pool by considering volatilization from tap water to indoor air. In terms of human health effects, we assessed both cancer and non-cancer effects. From the point of view of ecological risk, it was concluded that few risks were generally expected for aquatic organisms. Current releases of chloroform from manufacturing factories have been decreased gradually because of the voluntary management of hazardous air pollutants in Japan. The decrease resulted in the recent gradual decrease of chloroform concentrations in ambient air, which suggests that we will not have to encourage stricter control than the present. As for indoor air, we may need some ventilation.

Keywords

chloroform, risk assessment, risk management, by-product, emission, exposure, human health effects, ecological risk