Historical Trends of Polycyclic Aromatic Hydrocarbons in the Reservoir Sediment of the Dianchi Watershed, Southwest China

Using gas-chromatography/mass spectrometry (GC-MS) method dating data (Pb-210 and Cs-137) and OCPs signatures, the temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in dated sediment core from Baoxianghe reservoir in Dianchi watershed, Southwest China. The concentrations of total PAHs were in the range of 162.3-762.2 ng g(-1) from 1945 to 2013. There showed an obvious increase from 1960s to 2000s. The distributions of PAHs were influenced by local population and Gross Domestic Product (GDP) during the period between1962 and 2004. PAHs sources changed from biomass or domestic coal combustion (before 1980) to liquid fossil fuel combustion (after 1980). Total toxic toxicity equivalents (TEQs) of the carcinogenic PAHs were very low (3.03-28.08 ng g(-1)).