Contamination of Newly Emerging Contaminants, Polybrominated Diphenyl Ethers (PBDEs) in Sediments near E-waste Recycling Sites in South China

The contamination of polybrominated diphenyl ethers (PBDEs) in the Maozhou River watershed, Shenzhen, China was investigated. The eight target PBDE congeners, including BDE-28-47-99-100-153-154-183 and BDE-209, were detected in all sediment samples, indicating that the contamination is common in this watershed. Spatial variations were significant. The highest concentration of total PBDEs of seven congeners exclude BDE-209 (∑⁷PBDEs), mean of 12.72 ng g^-1 freeze-dried weight (dw), was found in the site closest to the Maozhou Industrial District with more than 10 Industrial Parks. This site also had the highest concentration of BDE-209 (648.89 ng g^-1 dw). The lowest concentrations of ∑⁷PBDEs and BDE-209 were found in the rural area about 5 Km away from industrial regions with respective averages of 1.56 and 23.61 ng g-1 dw. Mangrove sediment at the River mouth furthest away from industries accumulated more PBDEs than the rural area. In all sediment samples, BDE-209 was the most dominant congener making up more than 99% of total PBDEs. Other than BDE-209, the profile of the seven congeners varied from sites to sites, with BDE-28 and-99 being the most dominant congeners in the site closest to the Industrial District, while BDE-47 became more significant in sites further away. These results demonstrated the contamination of PBDEs in sediment, due to the rapid consumption of electronic products and the activities of e-waste recycling along Maozhou River, was very serious.