Spatial distributions and transport implications of short- and medium chain chlorinated paraffins in soils and sediments from an e-waste dismantling area in China
Authors: Chi Xu, Qin Zhang, Lirong Gao, Minghui Zheng, Lin Qiao, Lili Cui, Runhua Wang, Jie Cheng
Abstract
To investigate the spatial distributions, potential transport and ecological risks of chlorinated paraffins (CPs) in and around e-waste dismantling area, we collected soil samples within 5 km of the e-waste dismantling centers and sediment samples in the surrounding area from the lower reaches of Jiaojiang River. Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) were analyzed by two-dimensional gas chromatography coupled with electron-capture negative-ionization mass spectrometry (GC × GC-ECNI-MS). The SCCP and MCCP concentration ranges in soils were 68.5 to 2.20 × 105 ng/g dry weight (dw) and 507 to 4.40 × 106 ng/g dw, respectively. The ranges for the levels of SCCPs and MCCPs in sediments were 32.5–1.29 × 104 ng/g dw and 271–2.72 × 104 ng/g dw, respectively. No significant correlation was observed between total organic carbon (TOC) and CP concentrations (P > 0.05). The spatial distributions showed that the CP levels were closely related to e-waste pollution. Correspondence analysis revealed that shorter-chain and less chlorinated congeners were enriched in sediments from sites distant from e-waste pollution source, while longer-chain and higher chlorinated congeners were concentrated in soils and sediments collected near the pollution source, which indicated that complex environmental processes, such as transportation via atmosphere and/or water, and deposition, resulted in different CP profiles in different sampling locations and environment matrixes (e.g., soil and sediments). Principal component analysis (PCA) indicated that e-waste pollution could be the same source of SCCPs and MCCPs. The preliminary risk assessment indicated that CPs in soils within 1 km of e-waste dismantling centers at current levels posed a considerable risk to soil-dwelling organisms, and the sediment MCCPs in Jiaojiang estuary at present levels also posed a risk to sediment-dwelling organisms.
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