Concentration and composition of polycyclic aromatic hydrocarbons (PAHs) were determined for 75 HiVol PM_2.5 samples collected at the national station for background atmospheric monitoring at Tuoji Island from Nov. 2011 to Jan. 2013. The results showed that the total concentration of the 16 USEPA priority PAHs (Σ16PAHs) ranged from 4.7 to 41 ng/m³, with an average value of (17±10) ng/m³, and high PAHs concentrations occurred in cold seasons while low concentrations in warm seasons. An integrated approach of air mass back trajectories, molecular tracers, isomer ratios of PAHs and potential source contribution function analysis was used to identify potential sources. It is shown that biomass burning in Shandong Peninsula during summer is the main PAH source while the outflow of coal combustion and mixed emissions from Jing-Jin-Ji and adjacent areas contributes a high PAH level in cold season. The total toxic equivalent of PAHs (BaPeq) at this site ranges from 0.54 to 8.2 ng/m³, with an average of 2.8 ng/m³. Furthermore, the BaPeq levels in 39% of the total samples exceed the national standard of China, indicating the regional characteristic of PAH health risk in the Bohai Rim.

PM_2.5  /  PAHs  /  Tuoji Island  /  source identification  /  health risk