青藏高原持久性有机污染物研究现状与展望

Current Knowledge and Future Prospects Regarding PersistentOrganic Pollutants over the Tibetan Plateau

自21世纪以来,对地球上最大、最高的高原——青藏高原上持久性有机污染物的含量、传输途径和归宿的了解已逐步深入,回顾了关于青藏高原持久性有机污染物研究的主要成果。高海拔山区的观测技术和多尺度模型是产出这些成果的关键突破口,而第三极持久性有机污染物观测网填补了青藏高原地区持久性有机污染物数据的空白,为系统阐明南亚持久性有机污染物的排放特征,明确印度季风驱动下持久性有机污染物输入青藏高原的过程与范围以及揭示青藏高原高寒生态系统对部分持久性有机污染物的富集程度提供了基础。植被、土壤和冰川是持久性有机污染物的重要汇。由于青藏高原临近国家是持久性有机污染物的排放源地,使得持久性有机污染物可通过远距离大气传输和“冷捕集”作用在青藏高原环境中富集。因此未来需要开展长期监测,准确量化新型污染物对青藏高原生态环境的影响,阐明气候变化和人类活动共同影响下青藏高原环境变化的趋向。最后,考虑到跨境传输是青藏高原持久性有机污染物污染的主要原因,因此还应在持久性有机污染物排放法规方面积极开展全球/区域合作,以减少持久性有机污染物的迁移及其对青藏高原的不利影响。

Entering the 21st century,our understanding of the level,source,transport and fate of Persistent Organic Pollutants(POPs)over the Tibetan Plateau(TP),the largest and highest plateau on Earth,has been greatly enhanced.In this study,we have reviewed all the available literature to comprehensively understand the biogeochemical cycling of POPs over the TP.Based on the breakthrough of observation technology and multiscale model developed for the TP region,new insights were obtained.The establishment of the atmospheric POPs monitoring network fills the data gap of POPs in the TP,and clarifies the emission characteristics of POPs in South Asia.All these data depict the spatiotemporal variation of POPs over the TP and shed the light on the role of the Indian monsoon on POPs transport.Vegetation,soil and glaciers of the TP act as important sinks for POPs.Use of POPs in surrounding counties,Long-Range Atmospheric Transport(LRAT)and"cold trapping"by the TP can happen following emission-transport-deposition events,and leading to the enrichment of POPs in the TP environment.Due to the intensification of human activities in the surrounding area of the TP and the melting of glaciers and frozen soil caused by global climate change,POPs behavior and distribution on the TP got changed,which should be of great concern.Therefore,long-term and continuous monitoring should be carried out in future to accurately quantify the impact of POPs and some emerging compounds on the ecological environment of the TP;the trend of environmental change over the TP under the joint influence of climate change and human activities should be addressed.Finally,it should be considered that transboundary transport is the main cause of POPs pollution over the TP,and global/regional cooperation should be actively carried out in terms of POPs emission regulations to reduce POPs migration and their adverse impact of POPs pollution over the TP.