ATMOSPHERIC DEPOSITION OF MERCURY IN NORWAY - TEMPORAL AND SPATIAL TRENDS

Data from a study of Hg in the terrestrial environment in Norway are presented. Analyses of moss samples and comparison with wet deposition data indicate that dry deposition of gaseous Hg is important at northern latitudes. The Hg content of the humus layer of natural soils shows only moderate regional differences, but is to some extent dependent on atmospheric deposition from long-range transport and local point sources. Peat cores from ombrotrophic bogs provide information about recent and pre-industrial levels of Hg deposition, the ratio between levels varying from less than 2 to almost 10 depending on the location. Surprisingly high levels in surface peat in the northern part of the country support the conclusion indicated from moss analysis concerning the significance of dry deposition.