Seasonal variation and source apportionment of PAHs in TSP in the atmosphere of Guiyang, Southwest China

Total suspended particle (TSP) samples were collected during January to December in 2005 at urban and rural sites in Guiyang, and were analyzed for 14 particulate-phase polycyclic aromatic hydrocarbons (P-PAHs) using High Performance Liquid Chromatography (HPLC) with fluorescence detection. The total concentration of the P-PAHs ranged from 6.0-29.1 ng/m3 at monitoring sites, and 1.2-84.8 ng/m3 in and around Guiyang. P-PAHs concentration in samples collected from Guiyang possesses distinct seasonal variation with a higher concentration in winter and lower concentration in summer. PAHs with 5-ring were found to have the most distinct seasonal variation among other target PAHs. Correlations between the TSP concentration, ambient temperature (T), relative humidity (RH), and the P-PAHs concentrations were evaluated.It was found that the TSP had significant influence on the P-PAHs concentration with correlation coefficients of 0.69 (P < 0.01, n = 180). In addition, the P-PAHs concentration showed negative correlation with RH (r = − 0.28, P < 0.01, n = 180), and a moderate negative correlation with T (r = − 0.17, P < 0.05 n = 180). Diagnostic ratios and Principal Component Analysis suggest that the main pollution sources identified were coal combustion emission (52.5%), traffic gasoline (21.4%) and other miscellaneous sources (14.2%).

► PAHs in TSP were dominated by high molecular weight compounds. ► TSP concentrations influenced the particulate PAH concentrations. ► PAH concentrations had a strong negative correlation with relative humidity. ► Coal combustion emissions were the predominant source of PAHs in TSP in Guiyang.