Distributions of chlorinated paraffins and the effects on soil microbial community structure in a production plant brownfield site

The distributions of chlorinated paraffins (CPs) in soils and their ecological effects attract much attention, while site-scale data are still scarce. In this study, a comprehensive investigation was performed to understand the CP distributions at a CP production plant brownfield site, as well as their effects on soil microbial community. Short-, medium- and long-chain CPs (SCCPs, MCCPs, LCCPs) were detected in most samples with total contents ranging ND-5,090, ND-6,670, and ND-1450 ng g−1 (dw), respectively. A CP-hotspot was observed 10 m beneath the synthesis workshop, indicating the downward migration of CPs. The consistence of soil SCCP congener profiles with commercial product CP-52 suggested the leakage of CP products as the contamination source. Besides CPs, petroleum hydrocarbons (PHC) contamination also occurred beneath the synthesis workshop. Soil microbial community composition and diversity were significantly influenced by SCCPs (p