Hexabromocyclododecanes in Surface Soils from E-Waste Recycling Areas and Industrial Areas in South China: Concentrations, Diastereoisomer- and Enantiomer-Specific Profiles, and Inventory

Abstract

Hexabromocyclododecanes (HBCDs) are raising concern because of their potential persistence, bioaccumulation, and toxicity. In this study, we investigated the concentrations, diastereoisomer- and enantiomer-specific profiles, and mass inventories of HBCDs in 90 surface soils from two e-waste recycling areas (Qingyuan, Guiyu) and from industrial areas in South China. The mean concentrations of total HBCDs in the surface soils ranged from 0.22 to 0.79 and from 0.31 to 9.99 ng/g dw for two surrounding e-waste recycling sites and industrial areas, respectively. The highest total HBCD concentration (284 ng/g dw) was found at the e-waste recycling site in Qingyuan, while total HBCD levels fell dramatically with increasing distance from the recycling site, suggesting that the e-waste recycling activities were an important source of HBCDs. The diastereoisomer profiles in 75 of the 90 soil samples differed from those of the commercial products. The mean enantiomeric fraction values for α-, β-, and γ-HBCDs in soils ranged from 0.503(0.010) to 0.507(0.003), 0.494(0.003) to 0.506(0.009), and 0.502(0.003) to 0.511(0.006), respectively, suggesting that there was no stereoselective transformation of the three diastereoisomers. The mass inventories of HBCDs gave preliminarily estimates of 3.42 kg and 1.84 tonnes for the e-waste recycling areas and industrial areas, respectively. It is notable that the diasteroisomer and enantiomer profiles of this study failed to distinguish definitely that the isomeric transformation occurred during the product processing or in the environmental matrix. Further laboratory studies on abiotic and biotic transformation are needed to clarify this issue.

Organohalogen pollutants in surface particulates from workshop floors of four major e-waste recycling sites in China and implications for emission lists

“…α-HBCD was quite abundant in samples from Taizhou (50 ± 7%) and Qingyuan (59 ± 18%), whereas the mean proportion of α-HBCD (41 ± 21%) was comparable to that of γ-HBCD (42 ± 20%) in particulates from Guiyu but different from that of Chinese technical products (γ-HBCD: 81.6%). Variations in isomer profiles have also been reported in soil samples collected from the same e-waste recycling areas previously (Gao et al, 2011), and the variability in the diastereoisomer profiles of HBCDs in particulates may be attributable to a rapid photolytically mediated transformation of γ-HBCD into α-HBCD (Harrad et al, 2009) and likely a preferential degradation of γ-HBCD in dust (Abdallah et al, 2008).…”

Polybrominated diphenyl ethers in surface soils from e‐waste recycling areas and industrial areas in South China: Concentration levels, congener profile, and inventory

“…Detailed information regarding the study areas is available in several other studies [13,17,[19][20][21][22]. Briefly, GY and QY are the two of the biggest e-waste recycling centers in China and have an e-waste recycling history of more than 10 years.…”

Occurrence of brominated flame retardants (BFRs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) in agricultural soils in a BFR-manufacturing region of North China

“…The concentrations of TBBPA were at levels in the range of 0.30-32.2 ng/g in soils from Spain (Sánchez-Brunete et al, 2009) and ranged from nondetectable (nd) to 5.6 ng/g in farmland soil and 26-104 ng/g in soils from an e-waste site in Beijing, China (Xu et al, 2012). HBCD mean concentrations of 0.22-9.99 ng/g in industrial soils from South China (Gao et al, 2011) and a mean concentration of 0.02 ng/g in background soils in East China have been reported (Meng et al, 2011). The HBCD concentrations in soils at open waste dumping sites in Asian developing countries (with means of 0.04-0.54 ng/g) (Eguchi et al, 2012) were also low.…”