Kumari Minashree, Gupta S K, Mishra B K
Department of Environmental Science and Engineering, ISM Dhanbad, 826004 Jharkhand, India.
Department of Environmental Science and Engineering, ISM Dhanbad, 826004 Jharkhand, India.
Ecotoxicol Environ Saf. 2015 Mar;113:433-8. doi: 10.1016/j.ecoenv.2014.12.028. Epub 2014 Dec 26.
The lifetime cancer risk and the hazard index of trihalomethanes (THMs) through oral ingestion, dermal absorption, and inhalation exposure from supply water of five WTPs were analysed. THMs concentration varied from plant to plant and was found to be in the range of 274-511µg/l, which is much higher than the prescribed USEPA standards of 80µg/l. Chloroform was the most dominant THM followed by bromodichloromethane (BDCM), and dibromochloromethane (DBCM). Cancer risk analysis through multi-pathways exposure reveals that residents had a higher cancer risk through oral ingestion than other two routes of exposure. The lifetime cancer risks of THMs from supply water were 100 times higher than prescribed USEPA guidelines. The higher cancer risk found for Indian context than those reported for other countries like USA, UK, Japan, Australia, is mainly due to the higher concentration level of THMs, water intake and average body weight. The study also revealed that amongst different THMs, chloroform is the major THMs causing cancer risk through both oral and dermal route of exposure whereas in case of inhalation it was mainly because of BDCM. Average lifetime cancer risk analysis indicated that females are more prone to cancer risk than males. Oral ingestion is a major route indicating the potential impact of non-cancer risk while it was insignificant through dermal exposure. Sensitivity analysis of THMs revealed that chloroform is the predominant parameter followed by body weight and exposure duration influencing cancer risk.
分析了五个污水处理厂供水经口服摄入、皮肤吸收和吸入暴露途径的三卤甲烷（THMs）终生癌症风险和危害指数。各污水处理厂的THMs浓度各不相同，范围在274-511μg/l之间，远高于美国环境保护局规定的80μg/l标准。氯仿是最主要的THM，其次是溴二氯甲烷（BDCM）和二溴氯甲烷（DBCM）。通过多途径暴露进行的癌症风险分析表明，居民通过口服摄入途径面临的癌症风险高于其他两种暴露途径。供水的THMs终生癌症风险比美国环境保护局规定的指导值高100倍。印度背景下发现的较高癌症风险高于美国、英国、日本、澳大利亚等其他国家报告的风险，这主要是由于THMs浓度较高、水摄入量和平均体重较高。研究还表明，在不同的THMs中，氯仿是通过口服和皮肤暴露途径导致癌症风险的主要THM，而在吸入情况下，主要是由于BDCM。平均终生癌症风险分析表明，女性比男性更容易面临癌症风险。口服摄入是一个主要途径，表明存在非癌症风险的潜在影响，而通过皮肤暴露则不显著。THMs的敏感性分析表明，氯仿是影响癌症风险的主要参数，其次是体重和暴露持续时间。
