Investigating Short-Chain Chlorinated Paraffins (SCCPs) in China: A Review of Occurrences, Determination Techniques, Human Exposure Routes, Toxicity, and Risk Assessments

Chlorinated paraffins (CPs) are recognized as a novel class of persistent organic pollutants (POPs) and are categorized into short- (SCCPs, C10–13), medium- (MCCPs, C14–17), and long- (LCCPs, C≥18) chain CPs considering the carbon-chain length. Among them, SCCPs possess lower molecular weights, higher vapor pressures, and greater water solubilities compared to their longer-chain counterparts (MCCPs and LCCPs), which promote their environmental release. Consequently, SCCPs were designated as POPs of concern under the Stockholm Convention in 2017. This review concludes the recent research progress of SCCPs in China from 2015 to present, and we present a comprehensive overview of SCCP concentrations, encompassing diverse environmental matrices and human tissues, for example, air, water, soil, sediments, biota, food, human placenta, breast milk, blood, and organs (fat, kidney, liver, brain, bone, etc.). Whereafter, we summarize the development of SCCPs determination methods, benefiting from quantifying relative carbon-chain length and chlorine content of SCCPs correctly. Moreover, toxicity, toxicokinetics, and adverse health effects of SCCPs in humans from China are concluded and discussed. Meanwhile, we review the existing control and treatment technologies for SCCPs. Lastly, we describe some noteworthy and prospective issues that are worthy of further study. In the future, the relevant studies are still necessary to keep up with consecutive monitoring and evaluation of SCCP levels and relative potential health impacts in China.