城市回用水中多环芳烃致癌风险评价

为评价人群暴露于城市回用水中16种多环芳烃(polycyclic aromatic hydrocarbons,PAHs)对于人体健康的潜在风险,采用气相色谱-质谱(GC-MS)联用的分析化学方法对不同季节回用水中16种PAHs进行定量分析;在此基础上采用美国国家科学院和国家研究委员会提出的环境健康风险评价方法,分析不同回用条件下具有中国水体基质特色的城市回用水中PAHs健康风险.结果显示,回用水样中16种PAHs的总浓度为1 422.85 ng·L-1,污水处理厂二级出水水样16种PAHs的总浓度为1 791.77 ng ·L-1,经过处理后回用水中PAHs含量有所降低.风险评价分析结果显示,回用水在城市绿化、农业灌溉和景观娱乐3种不同回用途径下多环芳烃的致癌风险分别为788×10-8、2.77×10-6、3.04×10-6,总致癌风险为5.89×10-6.以上结果可以得出,回用水在城市绿化、农田灌溉和景观娱乐接触过程中多环芳烃所增加的致癌风险很低,回用水中多环芳烃的健康风险处于可接受水平.

Carcinogenic Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Reclaimed Water

Reclaimed water still contains a verity of hazardous substances which have strong carcinogenic and mutagenic effects on human and creature. Polycyclic aromatic hydrocarbons (PAHs) are the most typical one in those hazardous substances. In this paper, concentrations of 16 kinds of polycyclic aromatic hydrocarbons (PAHs) were analyzed, and the potential health risks of PAHs were assessed. Gas chromatography - mass spectrometry (GC-MS) was used to analyze the concentrations of 16 kinds of PAHs in different seasons. And then, the method of environment health risk assessment proposed by U.S. National Academy of Sciences and National Research Council was adopted to study the health risks of PAHs in reclaimed water in different reused conditions in China. Results show that total concentrations of PAHs in reclaimed water were 1422.85 ng·L^-1 and secondary effluent from sewage treatment plant were 1791.77 ng·L^-1. It was indicated that the concentration of PAHs in reclaimed water decreased after wastewater treatment. Carcinogenic risks of PAHs in three kinds of reuse approaches including urban greening, agricultural irrigation and landscape were assessed. The carcinogenic risks of PAHs in three reuse ways were 7.88×10^-8, 2.77×10^-6 and 3.04×10^-6 respectively, and the total carcinogenic risk was 5.89×10^-6. It can be concluded that the carcinogenic risk and noncarcinogenic risk were low in three different reuse approaches mentioned above, and the health risk of PAHs in reclaimed water was acceptable.