Concentrations and sources of PAHs in surface sediments of the Fenhe reservoir and watershed, China.

Sixteen PAHs in surface sediments at 28 sites throughout Fenhe reservoir and watershed were measured. The ∑PAHs concentrations ranged from 539.0 to 6281.7 with the mean of 2214.8ng/g. The 2-3 rings PAHs, contributing 55 percent to ∑PAHs, were the dominant species. Twenty-eight sites were grouped into three segments: Fenhe principal stream, estuaries of main branch streams, and Fenhe reservoir. ∑PAHs was highest in the estuaries of main branch streams. The ecological risk assessment was studied by biological thresholds. The results showed levels of PAHs might cause mild but not acute adverse biological effects. In addition, PAHs ratios, PCA/MLR and hierarchical clustering analysis were applied to evaluate the possible sources. Coal combustion (35 percent), diesel and gasoline emissions (29 percent and 16 percent, respectively) might be the important sources. For sites in Fenhe reservoir, the major sources were complex, while other two segments were mainly influenced by coal combustion source. Copyright Â