Characterization of polybrominated dibenzo-p-dioxins and dibenzo-furans (PBDDs/Fs) in environmental matrices from an intensive electronic waste recycling site, South China.

Information on environmental distribution and human exposures of polybrominated dibenzo-p-dioxins and dibenzo-furans (PBDDs/Fs) are little reported. In the present study, workshop dust, soil and sediment samples from Longtang and Shijiao, the intensive e-waste recycling sites within Qingyuan City, southern China, were collected and analyzed following the standard method. PBDD/F concentrations (sum of eight 2378-substituted PBDD/F congeners) in different environmental matrices were in the range of 122-4667 ng kg(-1) dry wt (dw) for workshop dust, 19.6-3793 ng kg(-1) dw for the top soils, and 527 ng kg(-1) dw for the surface sediment, which were substantially higher than those of reference sites. The long-distance transport of PBDDs/Fs also impacted the adjacent areas. Contribution of the most two toxic congeners (2,3,7,8-TBDD and 1,2,3,7,8-PeBDD) to the total toxic equivalent quantity (TEQ) increased significantly from "source" (dust) to "sink" (sediment). Dismantling and open burning were the two procedures contributing relatively higher level PBDDs/Fs to the atmosphere, while acid leaching would contaminate soils and waters directly. The estimated daily intakes of eight PBDD/F congeners via soil/dust ingestion and dermal absorption for local residents were higher than those contributed by seventeen PCDD/F congeners in the same set of samples. Children and e-waste processing workers were the most affected groups by the low-tech recycling activities there.