Occurrences, sources and risk assessment of short- and medium-chain chlorinated paraffins in sediments from the middle reaches of the Yellow River, China

Abstract

a b s t r a c tChlorinated paraffins (CPs), one class of hydrophobic and toxic compounds, are easily adsorbed into sediments and then pose potential risks to the ecosystem and human health. However, few researches on short-and medium-chain CPs (SCCPs and MCCPs) in sediments have been performed. In order to comprehensively investigate the spatial distributions, sources, and ecological risks of CPs, sediments collected from the middle reaches of the Yellow River were analyzed by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC Â GCeTOFMS). The concentrations of SCCPs and MCCPs ranged from 11.6 to 9.76 Â 10 3 ng/g dry weight (dw) and from 8.33 to 168 ng/g dw, respectively. No significant correlation was found between total organic carbon (TOC) and CP concentrations (P > 0.05). The spatial distributions showed that contamination levels of CPs were relevant to human activities. In addition, two types of sediment samples were classified by hierarchical cluster analysis (HCA) and results indicated the predominant congener groups were C 10 Cl 6e7 for SCCPs and C 14 Cl 7e8 for MCCPs. Principal component analysis (PCA) revealed that SCCPs and MCCPs in the sediments may have different sources, and SCCPs are likely to come from the production and use of CP-42 and CP-52. Moreover, complex environmental processes, including long-range transportation via the atmosphere and/or river, deposition and degradation of CPs, resulted in increased abundances of short chain and low chlorinated congeners in sediment samples compared with commercial mixtures, and different homolog patterns among samples. The significant negative correlation between SCCP concentrations and MCCP/SCCP ratios could be related to long-range transport of CPs. A preliminary risk assessment indicated that CPs at current levels posed no significant ecological risk.

Status of short-chain chlorinated paraffins in matrices and research gap priorities in Africa: a review

“…The ∑SCCP concentrations in sediments were in the range of not detected (ND)-2020 ng g −1 . The obtained concentrations were lower than those obtained in other studies while similar to the ones obtained in some (Chen et al 2011;Gao et al 2012;Sun et al 2017;Xu et al 2019b;Zeng et al 2017b;Qiao et al 2016), whereas higher in comparison with two studies (Qiao et al 2017;Iozza et al 2008). However, the Mann-Whitney U test indicated that MCCP concentrations in sediments were higher than those of SCCPs (p <0.001), which was attributed to the use pattern of commercial CP formulations in China.…”

Mass Fractions, Congener Group Patterns, and Placental Transfer of Short- and Medium-Chain Chlorinated Paraffins in Paired Maternal and Cord Serum

“…All the extracts were mixed and fractionated by a multilayer silica gel column. The detailed purification process was consistent with previous studies. , The fraction collected was concentrated and mixed with 2.5 ng of ε-HCH in 50 μL of cyclohexane.…”

“…Three commerical SCCP mixtures (51.5%, 55.5%, and 63% chlorine contents) and three MCCP mixtures (42%, 52%, and 57% chlorine contents), all at 100 μg/mL in cyclohexane, were obtained from Dr. Ehrenstorfer (Augsburg, Germany). SCCP and MCCP mixtures with other chlorine contents were achieved by mixing CP standard solutions in a certain proportion …”

“…The detailed purification process was consistent with previous studies. 27,28 The fraction collected was concentrated and mixed with 2.5 ng of ε-HCH in 50 μL of cyclohexane.…”

Chlorinated Paraffin Pollution in the Marine Environment

“…Coastal sediments are an important sink for CPs. Data collected from references. ,,,,,,,−,,,,, −, ,,− …”