Comparative Analysis of Pollutants in Polar, High- and Low-altitude Cryoconites

International audienceRapid industrialization in the Asian countries is one of the greatest contributors of anthropogenic pollutants such as Black Carbon (BC). These pollutants accumulate on the surface of glaciers and in lake ice. Microbes glue these pollutants together with dust in the form of cryoconites in a process called biological darkening, accelerating the melting of glaciers, snow and ice-caps. The Himalayan Mountain range is the second largest ice mass after the Polar region. Anthropogenic fossil fuel combustion and production of non-ferrous metals, leading to bulk release of trace metals such as, As, Cr, Cu, Ni and Zn into the atmosphere, have an adverse impact on the Himalayan ecosystem. There have been very few studies on the Himalayan cryoconites with the first one in 2017 showing high As levels; an element of concern for downstream human populations. Cryoconites in other regions, such as the Hans glacier, reveal high concentrations of anthropogenic Pu, Cs, Sr while those in Alpine glaciers are heavily enriched in artificial radionuclides. Simultaneous monitoring and comparison of various pollutants in polar, high- and low-latitudes will be important in understanding pollutant cycling. With this intent, we are undertaking a multidisciplinary assessment of the mineral, organic and biological components of cryoconites from the Arctic expedition, the Pyrénées and the Himalayas with a special focus on inorganic micropollutants such as artificial radionuclides, Hg and other trace metals