[Exposure Route of Dioxin-like Polychlorinated Biphenyls in Hair Based on Passive Sampling]

The main exposure pathways of DL-PCBs in local population were studied by analyzing the levels, distributions and relationships of DL-PCBs in pooled tree bark samples and hair samples collected in Kaiyuan, Yunnan Province, China. The results indicated that the concentrations of DL-PCBs in bark and hair samples were 4.0 pg·g^-1 to 88.9 pg·g^-1 and 4.1 pg·g^-1 to 19.3 pg·g^-1, respectively, suggesting the pollution levels of DL-PCBs were relatively low in local environment and human body. The predominant PCB congeners in bark and hair was PCB-118, contributing 48% of the total DL-PCB concentrations in the bark samples and 61% of the total DL-PCB concentrations in the hair samples. The DL-PCB congeners in tree bark might had the same sources and these compounds might be derived from atmospheric long-range transport. External and internal exposures were responsible for the DL-PCBs concentrations in hair, and external exposure contributed more to low chlorinated PCBs than to high chlorinated PCBs.