广州市主要饮用水源中重金属健康风险的初步评价

Preliminary health risk assessment of heavy metals in the main drinking water sources of Guangzhou

对广州市主要饮用水源地水中重金属浓度进行了调查研究,并应用US EPA推荐的健康风险评价模型对饮用水源地水中重金属的健康风险作了初步评价.结果表明,西江断面、北江断面、东江断面重金属的平均浓度范围分别为Cd0.21～3.96μg·L-1,As1.16～13.75μg·L-1,Cr0.96～13.16μg·L-1,Pb1.33～67.79μg·L-1,Hg0.05～0.69μg·L-1,Cu3.24～31.22μg·L-1,Zn8.51～619.33μg·L-1,Tl0.01～0.49μg·L-1.通过饮用水途径所致健康风险中,Cd和Cr在北江断面所引起的致癌风险最大,分别为1.08×10-5和2.32×10-4a-1,As在东江断面所引起的致癌风险最大,为9.13×10-5a-1,部分时段指标已高于国际辐射防护委员会(International Agency for Research on Cancer,ICRP)和美国环境保护局(US EPA)推荐的通过饮用水途径最大可接受风险水平(分别为5.0×10-5a-1和1.0×10-4a-1).重金属Hg、Pb、Cu、Zn、Tl通过饮用水途径引起的非致癌年平均健康风险值在10-11～10-9a-1之间,远低于ICRP推荐的最大可接受风险水平(5.0×10-5a-1).

Concentrations of Cr,As,Cd,Pb,Cu,Zn,Hg and Tl in the main drinking water sources （including the Xiachencun section of the Xijiang River,the Sanshui section of the Beijiang River and the Xintang section of the Dongjiang River） of Guangzhou were measured. And preliminary health risk assessments of these eight heavy metals in the water sources were conducted using the US EPA health risk assessment model. The results showed that the concentrations of the heavy metals in the drinking water sources were 0.21~3.96 μg·L-1 for Cd,1.16~13.75 μg·L-1 for As,0.96~13.16 μg·L-1 for Cr,1.33~67.79 μg·L-1 for Pb,0.05~0.69 μg·L-1 for Hg,3.24~31.22 μg·L-1 for Cu,8.51~619.33 μg·L-1 for Zn,and 0.01~0.49 μg·L-1 for Tl. Considering the health risk caused by carcinogens in the water,the largest risk levels for Cd and Cr were found in the Beijiang River （1.08×10-5 and 2.32×10-4 a-1,respectively） and the As levels in the Dongjiang River （9.13×10-5 a-1）,were higher than the maximum acceptable levels recommended by ICRP （5.0×10-5a-1） and US EPA （1.0×10-4a-1）. The non-carcinogen risk levels of Hg,Pb,Zn,and Tl ranged from 10-11 a-1 to 10-9a-1,much lower than the maximum acceptable level recommended by ICRP （5.0×10-5a-1）.