三峡库区主要城镇饮用水源地水质健康风险评价

Health risk assessment of drinking water sources of main towns in Three Gorges Reservoir

对三峡库区受回水影响的42个城镇饮用水源地水质进行调查研究,运用美国环境保护署推荐的健康风险评价模型对水源地水体中化学污染物质的健康风险作了初步评价。结果显示:研究区域致癌物的致癌风险偏高,三江水源地总致癌风险1.22×10^(-6)~7.19×10^(-5) a^(-1),支流水源地总致癌风险1.50×10^(-6)~7.19×10^(-5) a^(-1),地下水水源地总致癌风险3.05×10^(-6)~7.19×10^(-5)a^(-1),3种类型水源人均年致癌风险接近或超过了瑞典环境保护署、荷兰建设和环境署、英国皇家协会及国际放射防护委员会(ICRP)推荐的最大可接受风险水平,水源地类型的致癌风险顺序为地下水>支流>三江>水库;非致癌物的总致癌风险均小于或略超过荷兰建设和环境署推荐的可忽略风险水平(10-8 a-1)。因此,认为12种非致癌物通过饮用水途径引起的风险是可以接受的,其总致癌风险处于Ⅲ级、中风险状态。与全国其他区域相比,15种参评因子所占总致癌风险值比例大致相同。

This paper studies the 42 towns for drinking water quality which is affected by the backwater area in Three Gorges Reservoir. Using health risk evaluation model which is recommended by USEPA for water sources for chemical pollutants that makes a preliminary assessment of health risks. Results show that this area have higher canc er risk,The cancer risk reached 1.22 × 10-6 -7.19 × 10-5 a-1 in San Jiang water source area, 1.50 × 10-5 -7.19×10-5 a-1 cancer risk in tributaries and 3.05 × 10-6- 7.19 × 10-5 a-1 cancer risk in groundwater system, all of these three types cancer risk per capita cancer risk approaching or exceeding the Sweden Environmental Protection Department. The Netherlands Department of building and environment, from United Kingdom Royal Society and International Commission on Radiological Protection （ICRP） recommended;the maximum acceptable levels of risk from the biggest to the smallest shown as fellow：groundwater〉tributaries〉San Jiang〉reservoir. Non-carcinogenic material of total carcinogenic risk were less than or slightly over. Netherlands Construction and Environment Department recommended that ignored risk level is （10-8 a-1）. So those 12 species non-carcinogenic risk could be acceptable through drink ing water way. And the carcinogenic risk was in the third level fmiddle risk level）. Compared with other regions of the country,those 15 species accounted for roughly the same percentage of the total carcinogenic risk.