北京市饮用水源水重金属污染物健康风险的初步评价

Preliminary Health Risk Assessment of Heavy Metals in Drinking Waters in Beijing

对北京市城区 8个区和郊区 10个区、县 12 0个样点的饮用水中Cu ,Hg ,Cd和As的浓度进行了调查研究 ,并应用目前美国环保局推荐的健康风险评价模型对北京市各区县饮用水中重金属所引起的健康风险作了初步评价 .结果表明 ,城区 8个区和郊区 10个区、县重金属的平均浓度范围分别为Cu :0 81～ 6 96 μg·L-1,Cd :0 34～ 0 82 μg·L-1,Hg :0 10～ 0 74μg·L-1,As:0 19～ 3 0 2 μg·L-1.通过饮水途径所致健康风险中 ,As在通州区所引起的致癌风险最大 ( 2 0× 10 -5·a-1) ,Cd在昌平区的致癌风险最大 ( 2 3× 10 -6·a-1) ,但均低于国际辐射防护委员会 (ICRP)推荐的通过饮水途径最大可接受风险水平( 5× 10 -5·a-1) ;在北京市通过饮水途径引起的非致癌健康风险中 ,Hg的风险最大 ,Cu次之 ,但是两者风险水平均在 10 -8～10 -9·a-1,远低于ICRP推荐的最大可接受风险水平 .

Concentrations distribution of the Cu, Hg, Cd, As in drinking water in the 8 city districts and 10 counties in Beijing was studied based on a total of 120 random samples. Health risks associated with 4 metals in drinking water were assessed using USEPA health risk assessment model. The results showed that the concentrations of the heavy metals in drinking water in Beijing ranged from 0 81 to 6 96μg·L -1 for Cu, 0 34～0 82μg·L -1 for Cd, 0 10～0 74μg·L -1 for Hg and 0 19～3 02 μg·L -1 for As. Among the health risks caused by the carcinogens in drinking water, the largest risk associated with As should be in Tongzhou County (2 0×10 -5 ·a -1 ) and that with Cd should be in Changping County (2 3×10 -6 ·a -1 ), while both were significantly lower than the maximum allowance levels recommended by ICRP(5×10 -5 ·a -1 ). Among the non carcinogenic risks in drinking water, the largest risk was the risk associated with Hg, followed by Cu. The non carcinogenic risks levels ranged from 10 -8 to 10 -9 , much lower than the maximum allowance levels recommended by ICRP.