Determining Sources of Atmospheric Polychlorinated Biphenyls based on Their Fracturing Concentrations and Congener Compositions

Abstract

Air samples collected at 23 sites in Kanagawa Prefecture, Japan in 1998 and 1999 were analyzed for PCBs by a high-resolution gas chromatograph/mass spectrometer. Concentrations of PCBs ranged from 10 to 3290 pg/m3 N (geometric average, 120 pg/m3N) and were mostly less than 140 pg/m3 N. The toxicity equivalency quantity (TEQ) values of co-planar PCBs ranges from not detected (ND) to 0.35 pg-TEQ/m3 N (mean value, 0.00063 pg-TEQ/m3 N). Cl3-PCBs comprised the highest level in many air samples. PCB congeners in the samples collected on three consecutive days did not vary significantly, suggesting that variation of PCBs concentrations is minimal among the samples collected at same sites. On the other hand, the pattern similarities of PCBs in the samples collected at various areas were not consistent. Contamination from commercial PCBs (Kaneclor) was observed in some samples with high PCBs concentrations. The compositions of PCB congeners in the samples collected at the sites near municipal waste incinerators were similar to those of PCB congeners in the samples collected at common environments in Japan, whereas they were completely different from those in the exhaust gases collected directly from municipal waste incinerators. Consequently, contribution of exhaust gases from incinerators to PCB concentrations and/or compositions of all air samples collected in the present study was not observed.