The atmospheric transport and pattern of Medium chain chlorinated paraffins at Shergyla Mountain on the Tibetan Plateau of China

Large amounts of short chain and medium chain chlorinated paraffins (SCCPs and MCCPS) are released into the environment during production and usage. However, compared to SCCPs, there is a significant lack of attention for MCCPs. In this work, 83 air samples, collected between 2012 and 2015 from the Tibetan Plateau, were analyzed to investigate the airborne levels and distributions of MCCPs, further to evaluate their potential long-range transport behavior on the alpine area. The total air MCCP concentrations at Shergyla Mountain and Lhasa were between 50 and 690 pg/m(3) and 800-6700 pg/m(3), respectively. At Shergyla Mountain, MCCP concentrations in the air appeared an increasing trend with altitude, which indicated that MCCPs could potentially possess the ability of mountain cold trapping. C-14 and C-15 congener groups were the dominant homologue groups. The mountain contamination potential (MCP) of different congener groups is closely related to their equilibrium partitioning coefficients between octanol and air (K-OA), and water and air (K-WA). Increasing MCCPs levels might be a potential threat to the environment and human exposure. (C) 2018 Elsevier Ltd. All rights reserved.