AUPIFICATION AND CRITICAL LOADS IN SURFACE WATERS - KOLA, NORTHERN RUSSIA

Surface waters of large areas in the Nordic countries: Finland, Sweden, Norway and northwestern Russia are subject to acidification caused by acid precipitation. Precipitation in northern Kola is heavily polluted by the acids and heavy metals that are emitted from local smelters. Due to the geological and climatological conditions, large areas in the affected region are particularly sensitive to acid precipitation. Based on analyses of lake and river-water samples collected throughout the region in 1990-1992, it is shown that extensive surface-water acidification has taken place, particularly, in the mountain and remote tundra regions. Within a 30-km zone directly influenced by industrial activities, surface-water buffer capacity increases due to emissions of alkaline dust. The sulfur critical load for surface waters in northern Kola is exceeded in 48% of the territory and is at a maximum in the center of the region, on the hilly zone around the metal smelters, as well as in the remote tundra region.