Protecting glacial geoheritage: Pollution indices reveal trace element contamination in cryoconites and soils of protected and touristic valleys, Central Caucasus

Glacial and periglacial environments in alpine regions are increasingly threatened by anthropogenic activities and climate change, yet the supraglacial-periglacial redistribution of trace elements and role of nature reserves in these fragile ecosystems remains understudied. This research evaluates contamination levels in cryoconites and soils of two adjacent gorges in the Central Caucasus: the strictly protected Tsey Gorge and the tourism-intensive Skazka Gorge. Trace elements (Cu, Zn, Ni, Pb, Cd), basic physicochemical properties and pollution indices were analyzed. Zn was the most abundant element in both gorges (maximum of 79.00 mg·kg −1 ), attributed to natural geological background and legacy Pb-Zn mining. Conversely, Cu (max. 23.30 mg·kg −1 ) and Ni (maximum of 34.15 mg·kg −1 ) contamination in Skazka Gorge correlated with tourism infrastructure and related processes. Cryoconites acted as transient reservoirs, with meltwater facilitating the downstream transfer of trace elements to soils, evidenced by higher contamination in periglacial zone. Pollution indices classified Tsey as “unpolluted” and Skazka as “slightly polluted,” with moderate ecological risks in soils. The study demonstrates that protected areas and promotion of “eco-tourism” effectively reduced tourism-driven contamination, while geogenic and mining influences continue to affect the environmental quality of the studied alpine zone.