Short-chain chlorinated paraffins in soil, sediment, and seawater in the intertidal zone of Shandong Peninsula, China: Distribution and composition

Short-chain chlorinated paraffins (SCCPs) are components of chlorinated paraffins (CPs) with high persistence, bioaccumulation potential, and toxicity, and SCCPs have been listed on Stockholm Convention as persistent organic pollutants. In this work, we investigated the distribution and homologue group patterns of SCCPs in the intertidal zone of the Shandong Peninsula, which is surrounded by the Bohai Sea (BS) and Yellow Sea (YS). Total SCCP concentrations (ΣSCCPs) in the samples from the sites along the coast of BS were 64.14–452.9 ng/g (mean = 181.0 ng/g), which were higher than those of the YS (17.59–155.5 ng/g, mean = 108.5 ng/g). ΣSCCPs were generally higher in intertidal sediments than in coastal soils along the BS, which could be ascribed to local industrial emissions through river runoff and mid-estuarine maximum phenomenon that resulted from seawater intrusion. In contrast, the opposite trend was observed along the YS. The contribution of shorter chain (C10) and lower chlorinated (Cl5-7) SCCP congeners was higher when the sampling sites were more proximal to the sea than heavier ones because of their greater potential for long-range transportation. Similar homologue group patterns were observed in the intertidal zone of Shandong, thus indicating a uniform use of commercial CP mixtures. High SCCP concentrations and similar homologue group patterns as those of the STP effluent were observed in seawater samples, thus suggesting that massive insufficiently purified or nonpurified industrial effluents were discharged into the BS.