| With the rapid development of economy,pepple demand better quality of drinking water.As the result of soil erosion,sewage disposal,water pollution etal,the composistion of surface water is becoming more complex,trace-level organic compounds in drinking water can not be removed effectively by conventional water treatment technology,most of them do harm to human health.The organic compounds could enrich in the human body through food chain,and cause chronic poisoning.Therefore,it has come through a concern about the effect of organic compounds on the human health. Polycyclic aromatic hydrocarbons are the typical environmental toxic organic pollutants, it has nonbiodegradable and carcinogenic on human health.so,it is great important for improving the safety of drinking water to carry out the detection and research on polycyclic aromatic hydrocarbons in drinking wate.Polycyclic aromatic hydrocarbons detected in drinking water do harm to human health.PAHs and nitrated polycyclic aromatic hydrocarbons were assessed by solid phase extraction combined with gas chromatography mass spectrometry(GC/MS)analysis,water sample were collected from the waterworks of cities in china,and evaluated the health risk of polycyclic aromatic hydrocarbons in drinking water. The results are shown as follows:(1)In general,16 polycyclic aromatic hydrocarbons were detected in all the waterwoeks. Polycyclic aromatic hydrocarbons from raw water with total concentration of163.97～786.05 ng/L,the percentage of carcinogenic polycyclic aromatic hydrocarbons were over 20%.The concentration of polycyclic aromatic hydrocarbons from effluent water is 174.02～658.44 ng/L,they were under the relative limit of water supply industry standard in china,but the concentration of Benzo[a]pyrene in some waterworks were out of limits.(2) Polycyclic aromatic hydrocarbons were dominated by 2.3,4-ring in the raw water,other aromatic hydrocarbons were less.Composition tatio analysis was used to infer the sources of polycyclic aromatic hydrocarbons,and the results suggested that anthropogenic heavy fuel combustion was likely to the main source.(3)The spatial distribution characteristics of polycyclic aromatic hydrocarbons was "west high east low",the average total concentration as follow:Northwest China>Southwest China>north China>South China>Northeast China.(4)Comparing the the concentration of polycyclic aromatic hydrocarbons in raw and effluent water,the total removal efficiency was less.even.the effluent concentrations were higher than the raw concentrations.(5)Carcinogenesis risk factor and water environmental health risk assessment model were established to evaluate the health risk caused by polycyclic aromatic hydrocarbons from effluent water.The results indicated that the health risk was accepted, Benzo[a]pyrene based toxicity equivalency quantity(TEQBaP) is the evaluation index of the risk characterization,it can reduce the health risk assessment process to adopt TEQBaP-,nd make the evaluation simple and convenient.(6) Nitrated polycyclic aromatic hydrocarbons(nitro-PAHs) are considered to be mutagens or human carcinoges.several nitro-PAHs are believed to be far more mutagenic or carcinogenic than unsubstituted PAHs,so, it has come through a concern about the effect of nitrated polycyclic aromatic hydrocarbons on the human health.Many researchers have investigated the behaviors of nitro-PAHs in atmospheric environments.but there has been less investigation of nitro -PAHs in water environments.Exploring the existence status of nitrated polycyclic aromatic hydrocarbons in drinking water:5-nitroacenaphthene,2-nitrofluoren,3-nitrofluoranthene,1-nitropyrene were detected in all the waterworks, the average concentration of 2-nitrofluoren was 68.95 ng/L, was the largest one;the second one is 5-nitroacenaphthene,60.67 ng/L; the average concentration of 1-nitropyrene was 34.66 ng/L:the concentration of 3-nitrofluoranthene was lowest.34.21 ng/L. The spatial distribution characteristics of nitrated polycyclic aromatic hydrocarbons was similar as polycyclic aromatic hydrocarbons. |
