School of the Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China.
Department of Chemistry, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
Water Res. 2024 Nov 1;265:122300. doi: 10.1016/j.watres.2024.122300. Epub 2024 Aug 17.
The Tibetan Plateau, a recognized global sink for Persistent Organic Pollutants (POPs), lies adjacent to two major emitting regions, inland China and India. This unique geographical setting makes it a pivotal site for examining the presence and compositional evolution of POPs following their long-range atmospheric transport (LRAT). This study focuses on the current predominant POPs, chlorinated paraffins (CPs). We comprehensively screened 675 homologues of the very short- (vSCCPs), short- (SCCPs), medium- (MCCPs), and long-chain CPs (LCCPs) in six dated sediment cores across the extensive Tibetan area. The findings unveiled pronounced temporal disparities in CP concentrations and compositions between Tibet's southern and eastern sectors, reflecting divergent usage and emission chronicles of inland China and India. Notably, a market shift in China from regulated SCCPs to the in-use MCCPs and LCCPs was observed in the 21st century, contrasting with India's unregulated production of SCCPs. The Organization for Economic Cooperation and Development (OECD) Screening Tool, developed to assess the overall persistence (P) and long-range transport potential (LRTP) of organic chemicals, elucidated the erosion of CP source signatures induced by fractionation, a process that intensifies with transport distance from the source regions. This study enhances our understanding of the emission inventories and LRAT behavior of these transitional regulatory contaminants, highlighting the Tibetan Plateau's crucial role as an environmental sentinel in global pollution dynamics.
青藏高原被公认为是持久性有机污染物（POPs）的全球汇，它毗邻两个主要的排放区域：中国内陆和印度。这种独特的地理位置使其成为考察持久性有机污染物在长距离大气传输（LRAT）后存在和组成演变的关键地点。本研究重点关注目前主要的持久性有机污染物——氯化石蜡（CPs）。我们在广泛的西藏地区的六个有日期的沉积物核心中全面筛选了非常短链（vSCCPs）、短链（SCCPs）、中链（MCCPs）和长链 CPs（LCCPs）的 675 种同系物。研究结果揭示了藏南和藏东地区 CP 浓度和组成之间存在明显的时间差异，反映了中国内陆和印度使用和排放历史的差异。值得注意的是，在中国，21 世纪市场从受监管的 SCCPs 向正在使用的 MCCPs 和 LCCPs 转变，而印度则不受监管地生产 SCCPs。经济合作与发展组织（OECD）开发的筛选工具用于评估有机化学品的总体持久性（P）和长距离传输潜力（LRTP），该工具阐明了由于分馏导致 CP 源特征的侵蚀，随着与源区的距离增加，分馏过程加剧。本研究增进了我们对这些过渡性监管污染物排放清单和 LRAT 行为的理解，突出了青藏高原作为全球污染动态中环境监测站的关键作用。
