广州市感潮水源河段重金属分布特征及健康风险评价

对广州市沙湾水道(感潮河流型饮用水源地)涨、退潮期间13个断面7种重金属含量进行监测,并应用化学致癌和化学非致癌健康风险评价模型对该感潮河段重金属进行健康风险评价,研究该感潮河段重金属含量及其健康风险的时空分布特征。结果表明:该感潮河段重金属具有显著的空间分布差异,而感潮作用对重金属含量的影响并不明显;该感潮河段化学非致癌重金属污染物健康风险值相对较低,Cu、Hg、Zn的年平均风险值为10-10a-1,远远低于瑞典、荷兰、英国推荐的可接受限值,而化学致癌重金属污染物所引起的人体健康危害较高,化学致癌重金属污染物As、Cd的年平均风险值分别为10-5 a-1和10-6 a-1,其中Cd的年平均风险值与瑞典、荷兰、英国推荐的可接受限值接近(1×10-6 a-1),As的年平均风险值接近国际(ICRP)推荐值(5×10-5 a-1),致癌风险极大,应优先加以控制。

Distribution Characteristics and Health Risk Assessment of Heavy Metals in the Tidal River Sections in Guangzhou City

This paper reports a monitoring result of 7 kinds of heavy metals from 1 3 sections of Guangzhou Shawan waterway which is the drinking water source during ebb and flow tidal period.Then the paper con-ducts health risk assessment of heavy metals using chemical carcinogens and chemical non-carcinogens health risk assessment models,and explores the temporal and spatial distribution characteristics and health risks of heavy metals.The results show that the heavy metals in the tidal river has significant difference in spatial distribution,yet the effect of the tidal on the heavy metals content is not obvious.In addition,the health risk levels of chemical non-carcinogenic heavy metals,namely,Cu,Hg and Zn,are 10-10 a-1 ,are much lower than the recommended acceptable limits of Sweden,Holland and the UK (1 ×10-6 a-1 ).How-ever,the health risk levels of chemical carcinogenic heavy metals are much higher.Chemical carcinogens As and Cd have annually average risk levels of 10-5 a-1 and 10-6 a-1 respectively.The latter is close to the rec-ommended acceptable risk levels of Sweden,Holland and the UK(1 ×10-6 a-1 ),while the former is close to the recommended acceptable risk level(5 ×10-5 a-1 )of the International Commission on Radiological Pro-tection(ICRP),which is of high carcinogenic risk in need of priority control.