Cryoconite is a granular aggregate, comprised of both mineral and biological material, and known to accumulate atmospheric contaminants. In this study, cryoconite was sampled from seven high-elevation glaciers in Western China to investigate the spatial and altitudinal patterns of atmospheric mercury (Hg) accumulation in the cryoconite. The results show that total Hg (Hg-T) concentrations in cryoconite were significant with relatively higher Hg accumulation in the southern glaciers (66.0 +/- 29.3 ng g(-1)), monsoon-influenced regions, than those in the northern glaciers (42.5 +/- 20.7 ng g(-1)), westerlies-influenced regions. The altitudinal profile indicates that Hg-T concentrations in the northern glaciers decrease significantly with altitude, while those in the southern glaciers generally increase toward higher elevations. Unexpectedly high accumulation of methyl-Hg (MeHg) with an average of 1.0 +/- 0.4 ng g(-1) was also detected in the cryoconite samples, revealing the surface of cryoconite could act as a potential site for Hg methylation in alpine environments. Our preliminary estimate suggests a storage of similar to 34.3 +/- 17.4 and 0.65 +/- 0.28 kg of Hg-T and MeHg from a single year of formation process in the glacier cryoconite. Therefore, glacier cryoconite could play an important role in Hg storage and transformation, which may result in downstream effects on glacier-fed ecosystems under climate warming scenario.

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