| Because of the large volume of waste electrical and electronic equipment (WEEE) as well as the presence of brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol-A (TBBPA), heavy metals including Cu, Pb, Cd, Cr and Ni, and other hazardous compounds, the recycling and disposal of WEEE is of healthy and environmental concern. Considering that dust is the primary route for human intake of hazardous chemicals, assessment of human exposure to BFRs and heavy metals via dust ingestion, inhalation and dermal contact is of high scientific and policy interest. Our work examined both BFRs and heavy metals in dust from different WEEE recycling sites, and studied their negative effects on environment and human health.BFRs were widely used in old CRT TVs, the PBDEs profiles in TV interior dust showed that dust was the major carrier of contaminants. WEEE recycling sites were the primary sources of hazardous substances. In the waste TV recycling facility, PBDEs concentrations in dust from waste wires recycling line (722000ng/g) were the highest among the studied sites, followed by those in manual dismantling-sorting line (117000ng/g), whereas TBBPA concentrations were the highest in manual dismantling-sorting line (557ng/g) and waste printed circuit board (WPCB) recycling line (428ng/g). The contents of heavy metals in dust were closely related to those in materials, Cu and Pb were the most enriched metals in all dust samples. The highest concentration of Pb (22900mg/kg) was found in TV dismantling workshop-floor dust. Meanwhile, Cu was the predominant metal in dust from the WPCB recycling line, especially in dust collected from electrostatic separation area (42700mg/kg). Coarse crushing room should be additionally protected since it revealed that pollutants were released into the surroundings more easily during this process. Concentrations of PBDEs in dust out of the recycling facility were46.19-462.22ng/g, Cu were3.29-1537.88mg/kg and Pb were0.29-2566.25mg/kg. The advanced dismantling activity did not have serious impact on the surroundings.PBDEs in dust from the centre of Fengjiang dismantling site were11170ng/g, Cu was20268.75mg/kg and Pb was8056.25mg/kg, which led to high levels of pollutants in the environment around the site. The concentrations of hazardous substances in recycling sites in Wenling were significantly higher than non-recycling sites. Due to different types of WEEE and dismantling scales among different dismantling and recycling sites, Fengjiang had higher concentrations of BFRs and heavy metals than Wenling, and the PBDEs profiles were different in the two sites. Uncontrolled recycling and disposal of WEEE by simple dismantling, acid treatment, and open burning have resulted in severely environmental contamination in Taizhou.Our study showed the concentrations of PBDEs, Cu and Pb in dust from Fengjiang were20,30and6times higher than those in Shanghai recycling site, respectively. It revealed that relative closed dismantling workshops and advanced methods were better than open and primitive dismantling sites at preventing diffusion of pollutants.Human exposure assessment results showed that the average daily doses of pollutants through dust ingestion> dermal absorption> particulate inhalation. The workers in the dismantling facility had the highest health risks, while the exposure risks via dust for people in Taizhou were higher than in Shanghai recycling site. Scientific and effective methods should be used to minimize the exposure through dust. |
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