COMPARISON OF SULFUR AND HEAVY-METAL CONTENTS AND THEIR REGIONAL DISTRIBUTION IN HUMUS AND MOSS SAMPLES FROM THE VICINITY OF NIKEL AND ZAPOLJARNIJ, KOLA-PENINSULA, RUSSIA

Terrestrial moss and humus (the O-horizon) are often used separately f or determining and monitoring airborne heavy metal pollution. Here, we directly compare the results of analyses of moss and humus samples ta ken at a density of one site per 300 km(2) in a 12 000 km(2) area (45 samples) around the nickel smelter in Nikel, the nickel ore roasting p lant in Zapoljarnij, both in Russia, and the iron ore mine and mill ne ar Kirkenes in Norway. The samples were air dried, digested in cone. H NO3 and analysed for more than 30 elements by ICP-MS and ICP-AES at th e laboratory of the Geological Survey of Finland (GTK). For most eleme nts, observed levels and variations are considerably greater in soil t han in moss. The main contaminants, Ni and Cu, reach equally high medi an levels in the moss and soil, but maximum values are far higher in s oil. Both media show comparable regional distribution patterns for the heavy metals, but not for sulphur. Cu and Ni can be used to delineate the limits of contamination in the survey area. Both media show the s ame picture, with a generally very steep gradient from east to west an d background levels being reached 30-50 km from the nickel smelter. Wh en moss is used, Cu/Ni, Cu/S and Ni/S ratios can be used to separate i nput from the smelting and roasting processes in Russia. Both media ar e well suited to use separately to detect airborne pollution in this h eavily contaminated area. The moss data are generally easier to interp ret, but moss is not available at the most polluted sites. Levels for many elements other than Cu and Ni are close to the detection levels i n moss samples, but not in humus samples. Information gathered from bo th media thus complement each other in a regional multi-element survey .