Environmental Behavior Of Short-Chain Chlorinated Paraffins In Multi-medium

As potential persistent organic pollutants, SCCPs (Short chain chlorinated paraffins) are under review by Stockholm Convention in recent years. They can pose risks to ecological environment and human health, because of their persistence in the environment, bioaccumulation through the food web, potential of long-range transportation and high toxicity. However, the researches about analytical methods, environmental occurrence and toxic effect are very limited. In this thesis, we studied the distribution level and environmental behaviors of SCCPs in different environmental medium, by using GC-ECNI-LRMS (Gas phase-electron capture negative ion low resolution mass spectrometry), aiming to obtain the related data of SCCPs in China.Firstly, we investigated the pollution level, spatial distribution and congener profiles of SCCPs in soils in Taizhou, Zhejiang province, a major e-waste dismantling area in China. The results showed that SCCPs were detected in26soil samples, with the total concentrations ranging from47.95to1298ng·g-1d.w.(mean value of276.7ng·g-d.w.), and the chlorine content were in the range of59.1%-62.8%. The concentration of SCCPs is significantly higher than that of other POPs, such as PCBs, PBDEs and PCDD/Fs. A significant decreasing trend of the total concentrations of ESCCPs was found in the soil samples with increasing distance from Fengjiang. As for the congener profiles, C10and Cl6,7were the dominant homologue groups among all SCCPs congeners, similar with that of CP-52, the major industrial products in China. Principal component analysis indicated e-waste dismantling activities might be a major source of SCCPs releasing to the ambient environment.Secondly, we also studied the current status of SCCP pollutions, potential sources and transport pathways in the Bohai Sea (BS) and Yellow Sea (YS). Total SCCP concentrations in the surficial sediments were in the range of14.5～85.2ng·g-1d.w. with an average level of38.4ng·g-1d.w., and the corresponding TOC normalized concentrations varied from1.8to36.2μg·g-1.TOC-1. The spatial distributions of ΣSCCPs in surficial sediments of the BS and YS showed a clear decreasing gradient from the nearshore areas to the open waters, suggesting that the grain size and the TOC of the sediment play important roles in retaining hydrophobic organic chemicals, and the cotransport of the chemicals via the atmosphere and with the water current. Generally, the spatial distribution patterns of TOC matched the SCCP concentrations in the surficial sediments. The concentrations of ΣSCCPs ranged from11.6-94.7ng·g-1d.w.(1.1～10.5μg·g-1·TOC-1) in sediment core YS1and ranged from14.7to195.6ng·g-1d.w.(1.5～24.1μg·g-1·TOC-1) in sediment core YS2. The consistency of down-core profiles of ΣSCCP concentration and depositional flux for the two cores, indicated a stable dynamic environment in the central mud area of the YS. A multivariate regression analysis model implied that the local input, particularly the fluvial contributions to the nearshore sites, may outweigh latitude, longitude and TOC, in influencing the ΣSCCP concentration.Finally, we studied SCCPs concentrations and congener profiles in80food samples purchased from the market in Beijing, in order to evaluate the exposure levels of SCCPs to the general population in Beijing by food intake. The results showed that ΣSCCPs concentrations ranged from18.42～2685ng·g-1d.w., with the degree of chlorination of59.09%～63.21%(average value of61.32%). Thereinto, ΣSCCPs concentrations in meat and seafood were significantly higher than others, while that of fruits was lowest. There was a clear linear relationship between the total content of ΣSCCPs and fat content. Compositional pattern analysis suggested that C10and C11were the most predominant homologue groups, with regards to chlorine contents, the proportion was Cl7>Cl6>Cl8>Cl5>Cl9>Cl10. As the increasing of ΣSCCPs concentra-tions, the percentage of C10-11gradually decreased, while C12-13increased. Otherwise, SCCPs total daily intake decreased with the age increasing. In all, the current levels of SCCPs posed no risks to human health to the general populations of Beijing by food consumption.