An assessment of polybrominated diphenyl ethers and polychlorinated biphenyls in the indoor dust of e-waste recycling facilities in South Africa: implications for occupational exposure.

Workplace exposure to persistent organic pollutants is a concern for human health. This study examined the presence of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in the indoor dust from two major e-waste recycling sites and a university electronic equipment repair workshop in Durban, South Africa, in order to evaluate the implication of dust for occupational exposure. The mean ∑(n = 8)PBDEs and ∑(n = 3)PCBs were 20,094 and 235 ng g(-1), respectively. The levels of PBDEs and PCBs obtained in one of the recycling sites (123-27,530 and 161-593 ng g(-1)) were significantly higher than the levels obtained (91-7686 and <DL-42 ng g(-1), respectively) in the same site after site cleanup/maintenance. Occupational exposure was assessed for different exposure scenarios by using the 5th and 95th percentile, and the median and mean concentrations measured at the sites. By assuming a mean and a high dust intake rate, the average and 95th percentile daily exposure doses (∑DED/ng kg(-1) bw day(-1)) of PBDEs were 3.98, 8.52 and 7.58, 16.19, respectively, and of PCBs were 0.047, 0.094 and 0.089, 0.179, respectively. The ∑DEDs of PBDEs and PCBs were lower than the reference (RfD) values for BDE 47, BDE 99, BDE 153 and BDE 209, and Aroclor 1254 and 1016. Nevertheless, continual exposure to high levels of these pollutants is a concern; but as shown, the exposure can be significantly reduced if the e-waste facilities are cleaned thoroughly regularly.