PCBs, PBDEs and dioxin-related compounds in floor dust from an informal end-of-life vehicle recycling site in northern Vietnam: contamination levels and implications for human exposure

摘要

Floor dusts from Vietnamese end-of-life vehicle (ELV)-processing households were investigated to elucidate the contamination levels and exposure risk of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and dioxin-related compounds (DRCs). The concentrations were in order of PBDEs (260-11,000, median 280 ng/g overall) > PCBs (19-2200, median 140 ng/g) > dioxin-like PCBs (8.8-450, median 22 ng/g) polybrominated dibenzo-p-dioxin/dibenzofurans (PBDD/Fs, 2000-28,000, median 8500 pg/g) > polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs, 440-4100, median 1800 pg/g) > MoBPCDD/Fs (1.9-1200, median 250 pg/g). Concentrations of PCBs and DRCs were higher than those reported for Vietnamese urban houses, indicating ELV processing as a significant source of these contaminants. Higher concentrations of PCBs relative to PBDEs suggest the abundance of old electrical capacitors/transformers in ELVs. The PBDD/F and PCDD/F profiles were indicative of DecaBDE-containing materials and combustion sources, respectively. PBDFs, PCDFs and DL-PCBs were the most important dioxin-like toxic equivalent (TEQ) contributors. The estimated PCB and TEQ intake doses from dust ingestion approached or exceeded the reference doses for children living in some ELV-processing households, indicating potential health risk. More comprehensive risk assessment of the exposure to PCBs and DRCs is required for residents of informal ELV recycling sites.