Distribution and Source Apportionment of Polycyclic Aromatic Hydrocarbons in Bank Soils and River Sediments From the Middle Reaches of the Huaihe River, China

Bank surface soil and river sediment samples from the middle reaches of the Huaihe River were analyzed by GC-MS for polycyclic aromatic hydrocarbons (PAHs). The total PAHs concentrations ranged from104 to 947 ng/g in bank soils and from 83 to 2599 ng/g in river sediments. The PAHs levels of the studied samples are relatively higher as compared to those from other world regions, which suggest an enhanced deposition of atmospheric PAHs derived from the emissions of fossil fuel combustion in this area. Possible sources from soil and sediments were diagnosed by the paired PAHs isomer ratios and principal components analysis, and the results indicate that the PAHs in the soils mainly came from coal combustion (74%) followed by combustion of refined petroleum products (26%), and in the sediments mainly from pyrogenic sources (89%) followed by petroleum sources of oil spill emissions (11%). The PAHs exposure risk assessments show that PAHs in majority of the sediments did not pose threats to the ambient ecosystem. However, the calculated total toxic benzo[a]pyrene (BaP) equivalent of PAHs in soil and sediment indicate that BaP is the most potentially carcinogenic individual PAH.