| Polycyclic Aromatic Hydrocarbons (PAHs) are a kind of persistent organic pollutant widely distributed on earth. According to reports, PAHs have been detected in the waters and fish of some rivers and lakes in China. Hanjiang is the largest tributary of the middle Yangtze River and industry along the lower Hanjiang River has developed rapidly and discharge of industrial waste threatens the water quality. In this study, 16 PAHs, identified as priority pollutants by the U.S. Environmental Protection Agency (USEPA), were measured in water and fish collected from the lower Hanjiang River. The distribution of PAHs in the water and fish were analyzed and a health risk assessment was carried out using the assessment model recommended by USEPA. In December of 2015, water samples were obtained at the intake of eight representative water works and samples of seven typical fish species were collected from the corresponding river sections:Cyprinusauratus, Cyprinuscarpio, Squaliobarbuscurriculus, Sinipercachuatsi, Silurusasotu, Peltebagrusfulvidraco and Culterilishaeformis. The PAHs were determined by gas chromatography-mass spectrometry (GC-MS) and common abbreviations for the PAHs are used to save space. Six PAHs were detected at all eight sampling cross-sections: Nap, Ace, Phe, An, BaA and BkF. The detection rates of Fle, Acy, Flu, Pyr, Chr, BaP, DahA and BghiP were, respectively, 50%, 25%, 62.5%, 25%, 25%, 75%, 12.5% and 25% and BbF and InD were not detected. The total content of the 16 PAHs in the water of the lower Hanjiang River averaged 100.67ng/L, with a minimum value of 65.8ng/L and maximum value of 155.94ng/L. The structural composition of PAHs was dominated by low molecular weight (LMW) PAHs (70.4%), followed by medium molecular weight (MMW) PAHs (22.2%) and high molecular weight (HMW) PAHs (7.4%). The content of the 16 PAHs in the seven fish species ranged from (43.42±0.50ng/g) to (113.06±3.57ng/g). LMW PAHs, MMW PAHs and HMW PAHs accounted, respectively, for 57.9%, 20.2% and 21.9% of the total PAH content. HMW PAHs in fish were significantly higher than in water, indicating a higher bioaccumulation in fish. The health risk assessment shows that the overall health risk of PAHs in drinking water is low, from 2.25×10-8/a to 5.32×10-8/a. The health risk of PAHs in edible fish is acceptable, varying from 8.00×10-7/a to 2.08×10-6/a, lower than the maximum acceptable risk level (5.0×10-5/a) recommended by International Commission on Radiological Protection. However, the health risk level of PAHs for several fish species was higher than the acceptable value (1.0×10-6/a) recommended by USEPA. |
