Characteristics of Polychlorinated Biphenyl in the Air and Soils from Pearl River Delta, China

To explore distribution of polychlorinated biphenyl (PCB) in the air and soils from Pearl River Delta, the air and soil samples were collected the concentrations of PCBs detected by GC-MS. The results indicated that the concentration of total 24 PCBs (Σ₂₄PCBs) in air ranged from 240 to 2 258 pg/m³ with a mean value of 1 243 pg/m³. In the atmosphere, PCBs existed mainly in the gas phase, and three to five chlorinated biphenyls accounted for more than 90% of the total PCBs. There had been small fluctuations of concentrations of PCBs in the atmosphere in Pearl River Delta area since 2001, indicating the possibility of release sources of PCBs in the area. The concentration of total 24 PCBs (Σ₂₄PCBs) in soil ranged from ND to 20.68 ng/g with a mean value of 3.77 ng/g. Tri-CBs and tetra-CBs are the main congeners of PCBs in soil, averagely accounting for 45% and 19% of the total PCBs. In some places, the ratio of lighter PCBs decreased, while the heavier increased.