Occurrence and distribution of polybrominated diphenyl ethers in soils from an e-waste recycling area in northern China

Abstract

Polybrominated diphenyl ethers (PBDEs) are widespread persistent organic pollutants (POPs) because of their extensive use in diverse electronic products, which have posed great threats to human health and ecosystem. In this study, a total of 54 soil samples were collected from an e-waste recycling area in Tianjin, northern China for analyzing the occurrence and distribution of 14 PBDE congeners. The concentrations of BDE 209, ∑₁₃PBDEs and ∑₁₄PBDEs in the soils from Ziya e-waste recycling area were 2.9-2666 ng/g dw (dry weight) (average 90 ng/g dw), 3.0-41 ng/g dw (average 13 ng/g dw) and 5.9-2699 ng/g dw (average 103 ng/g dw), respectively. The ∑₁₄PBDEs concentration showed a dramatic decrease from the central area to the surrounding area. Generally, PBDEs in the northern part showed higher levels than the southern part of the e-waste recycling area due to the wind direction in Tianjin. Deep soil was less polluted by PBDEs, which largely comes from the deposition, migration and infiltration of PBDEs in the surface soils. Overall, PBDEs level in the studied area was much lower than some typical e-waste recycling areas in south China, such as Guiyu and Qingyuan, but significantly higher than the non-e-waste recycling areas. BDE 209, BDE 138 and BDE 28 were the three dominant PBDE congeners in the soil. Principal component analysis (PCA) indicated that the commercial penta-BDEs and deca-BDE could be considered as the main sources of PBDEs pollution in this region. Redundancy analysis (RDA) suggested that the local PBDEs sources rather than soil properties influenced the PBDEs distribution in Ziya e-waste recycling area. This study systematically revealed the occurrence and distribution of PBDEs in soils from the biggest established circular economy park in northern China.

Keywords: E-waste; Polybrominated diphenyl ethers; Soil; Soil properties; Spatial distribution.