Temporal variation and meteorological dependence of polychlorinated biphenyls in atmospheric PM_(10) of Jinan, China

摘要

To explore the PCB pollution characteristics in the airborne particulate matter, seven indicative polychlorinated biphenyls (PCBs) in atmospheric PM_(10) were determined weekly in Jinan, China. PCB concentrations, profiles, temporal distribution pattern and the correlations between Σ7PCBs and the meteorological conditions were analyzed, aiming to quantify the pollution level of PCBs in urban air. All the samplers were extracted by accelerated solvent extraction (ASE) and analyzed by gas chromatography (GC). The monthly concentrations of Σ7PCBs were 81.4-2335.2 fg/m~3. A distinct seasonal variation of PM_(10)-associated PCBs exhibited. Higher concentrations of PCBs in cold weather than warm weather was found. PCB28 and PCB52 were the major components of PM_(10)-associated PCBs in cold weather, while PCB 118 and PCB 180 dominated in warm weather. The fresh emission sources in cold weather, such as the burning of coal for domestic heating, were suggested to be a major influence factor. A significant correlation (p<0.05) was found between the total PCB congeners and atmospheric pressure. Heavy rainfall can also impact PM_(10)-PCBs significantly. The weak correlation coefficient between atmospheric PCBs and wind speed suggested that the inefficient dispersion and no significant pollution sources around.