Release of Perfluoroalkyl Substances From Melting Glacier of the Tibetan Plateau: Insights Into the Impact of Global Warming on the Cycling of Emerging Pollutants

Abstract

The Tibetan Plateau (TP) has encountered rapid warming, with more than 50% of lakes expanding and 80% of glaciers retreating. Melting glaciers are known as a secondary source of pollutants, but the dynamics and release features of water‐soluble emerging chemicals have not been studied in the TP. Glacial ice and snow, meltwater runoff, rain, and lake water were collected in Nam Co basin, in the central TP. The total concentrations of perfluoroalkyl acids (PFAAs) were 1,413 pg/L for glacial ice, followed by 1,277 pg/L for meltwater runoff, 980 pg/L for lake water, and 616 pg/L for rain. Perfluorobutanoic acid is dominant in runoff and glacial ice, while lake water contained high proportions of perfluorobutane sulfonate and perfluorooctane sulfonate. During the melting season, meltwater runoff generally had greater PFAAs concentrations, and the PFAAs release fluxes were strongly related to the glacial melt intensity. Due to the direct input of PFAAs by melted glaciers, south shore of Lake Nam Co contained higher PFAAs concentrations. The estimated input fluxes of PFAAs to the lake by rain and glacial and nonglacial runoff were 1,425, 1,342, and 2,192 mg/day, respectively. Taken together, these evidences suggest that melting glaciers are sources of PFAAs, while the lake is the receptor. Given the continuity of glacial melt and high concentrations of water‐soluble emerging pollutants in glacier, the melting process will increase the risks of emerging pollutants to freshwater sources and should be of great concern.

Rain Amplification of Persistent Organic Pollutants

“…Snow deposition is limited to cold regions and/or cold periods of time, while rain precipitation occurs widely for different seasons and across climatic regions. Furthermore, there are observations that concentrations in rivers increase after strong rain events. ,,,− Such large concentrations would be driven by the amplification of POPs by rain and the focusing of water in rivers from the watershed. Future work should be focused on studying the role of wet deposition on the cycle and occurrence of organic pollutants, especially in terms of its spatial and temporal dynamics, and extending this assessment to chemicals of emerging concern.…”

Microplastics in a Remote Lake Basin of the Tibetan Plateau: Impacts of Atmospheric Transport and Glacial Melting

“…The Tibetan Plateau (TP) contains the largest volume of glaciers outside the polar regions and has underwent rapid warming during the past 2 decades . Previously, studies have presented evidence that Tibetan glaciers continuously release trace toxicants and hydrophilic contaminants such as mercury and perfluoroalkyl substances into lakes. , On the other hand, microplastics had been found in the Tibetan glacier, lakes, , and a few rivers . However, these studies mainly reported the concentrations and compositions of microplastics in either glacier ice or lake/river waters, without consideration of the atmospheric fallout and glacier runoff.…”

A Perspective of the Cumulative Risks from Climate Change on Mt. Everest: Findings from the 2019 Expedition

“…The global signature of chemical pollution emergent from the cryosphere is increasing as melt progresses [ 35 ]. High alpine and Polar environments see the most disproportionate warming [ 37 , 38 ], but are also the most critical global water towers, distributing water to millions of people [ 39 ].…”