Lee S C, Guo H, Lam S M J, Lau S L A
Department of Civil and Structural Engineering, Research Centre for Urban Environmental Technology and Management, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Environ Res. 2004 Jan;94(1):47-56. doi: 10.1016/s0013-9351(03)00067-7.
The lifetime cancer risk and the hazard index of trihalomethanes (THMs) through oral ingestion, dermal absorption, and inhalation exposure from tap water in 19 districts in Hong Kong are estimated. The most dominant THMs are chloroform and bromodichloromethane (BDCM) in Hong Kong tap water. Among the three different pathways, residents have a higher risk of cancer through oral ingestion than through the other two pathways. The lifetime cancer risks through oral ingestion and dermal absorption for BDCM make the highest percentage contribution (59%) to total risks, followed by chloroform (24%). The chloroform and BDCM are at or above the negligible risk level of 10(-6) by a factor of 10 or more in most districts. Among the 19 districts, people living in Sai Kung have the highest risk of cancer due to the THM exposure through the multipathways, mainly because of the exposure to BDCM and dibromochloromethane (DBCM). The total cancer risk analysis indicates that each year approximately 10 out of the seven million Hong Kong residents could get cancer from the daily intake of water.
估算了香港19个地区居民通过饮用自来水、皮肤接触和吸入途径摄入三卤甲烷（THMs）的终生癌症风险和危害指数。香港自来水中最主要的三卤甲烷是氯仿和溴二氯甲烷（BDCM）。在三种不同途径中，居民通过饮用摄入患癌风险高于其他两种途径。BDCM通过饮用摄入和皮肤接触的终生癌症风险对总风险的贡献率最高（59%），其次是氯仿（24%）。在大多数地区，氯仿和BDCM的风险达到或超过可忽略风险水平10(-6)的10倍或更多。在这19个地区中，西贡居民因通过多种途径接触三卤甲烷而患癌风险最高，主要是由于接触了BDCM和二溴氯甲烷（DBCM）。总体癌症风险分析表明，香港700万居民中每年约有10人可能因每日饮水而患癌。
