Pcbs in Soils around an Old Electric Transformer Factory in North China

Abstract

The 28 surface soil samples (0-10 cm) were collected from the urban area of Baoding city nearby an old electric transformer factory for analysis of 84 PCB congeners. Total PCBs concentrations ranged from 0.69 to 11.15 ng/g (mean: 3.62 ng/g). The PCBs concentration (5.72 ng/g) for sampling sites in the vicinity (0-2.5 km) of the transformer factory was higher than that (2.96 ng/g) for other sampling sites. Compositional patterns of individual congener and homologs were similar to those of Chinese transformer oils. The top five congeners were PCB-6, 18, 22, 33 and 31/28 among the identified PCBs. Low chlorinated PCBs (di-to tetra-CBs) accounted for 69.58% of total PCBs concentrations and the predominant PCB homologs were tri-CBs (46.38%), penta-CBs (13.73%) and di-CBs (9.47%), respectively. Principal component analysis showed that technical formulations such as Chinese transformer oil, Aroclor1242, 1016, KC-300 and A-30 were the main sources of soils PCBs from Baoding city. The TEQ concentrations based on ten dioxin-like PCBs ranged from 0 to 26.0986 ng/kg with the mean value as 7.3336 ng/kg.