Pollution Characteristics and Ecological Risk Assessment of PAHs in Water and Fishes from Daqing Lakes

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in 30 water samples and 5 tissues (gill, liver, brain, kidney and muscle) of 36 fishes which were collected from 18 typical lakes of the Daqing lakes group, China were measured between February and April 2012. The results of PAHs concentrations in the water showed that the range of total concentrations was 0.2-1.21 μg x L(-1) and the highest concentration was found in the Yueliangpao Lake. Clustering analysis of statistical method was used to classify the concentrations of PAHs in the water of 18 lakes, and PAHs source and evaluation of ecological risk in different lake groups were obtained respectively based on the analysis of PAHs ratio and the species sensitivity distributions method. The results of cluster analysis about PAHs concentrations in the water of 18 lakes showed that all the lakes were divided into 4 lake groups. Yueliangpao (YLP) and dongdahai (DDH) lakes were respectively divided into a separate group and the other 14 lakes were divided into two groups named XHH group and DQSK group. PAHs in the water of lakes were mainly from wood and coal burning except that the PAHs of the water in YLP group was caused by oil contamination. According to the surface water quality standard of the world and China, the concentrations of PAHs in the water of 4 lake groups all exceeded the standard variously. The PAHs concentrations of most water samples in YLP group and XHH group exceeded the 16 PAHs limit value of Environmental Protection Agency (US EPA) standard, especially, the concentration of Benz[a] pyrene with the strongest carcinogenicity of YLP group exceeded Chinese surface water quality standard. While in the DQSK lake group and the DDH lake group, several PAHs contaminations of water samples exceeded the standard. The tested and statistical results of 16 PAHs concentrations in 5 tissues of Cyprinus carpio and Hypophthalmichthys molitrix fish species in Daqing lakes showed the concentrations of anthracene in the gill tissue of Cyprinus carpio were significantly greater than those in the Hypophthalmichthys molitrix, while other 15 PAHs concentrations had no difference between the two species. Among the different tissues of Hypophthalmichthys molitrix or Cyprinus carpio, the concentrations of PAHs in the liver and kidney tissues which are the important tissues of PAHs accumulation were significantly greater than those in the muscle, gill and brain tissues of fish because of their pervasion ability of pollutants. The results of ecological risks of PAHs in water samples to different aquatic organism species and health risk of PAHs to human through the consumption of fish showed that low ecological risk to aquatic organism species and health risk of PAHs in the muscle of Hypophthalmichthys molitrix and Cyprinus carpio to human were observed in the 4 lake groups.