Heavy metal contamination of the terrestrial environment from long-range atmospheric transport: Evidence from 35 years of research in Norway

Abstract

Over the last 35 years the temporal and spatial trends of heavy metal deposition have been followed at regular intervals all over Norway. From the extensive evidence available it is clear that airborne Pb, Zn, Cd, As, Sb, Sn, Hg, and V have all been added in excessive amounts to the environment in the southernmost part of the country. Analyses of aerosol samples, precipitation, moss samples, and surface soils all demonstrate substantial contamination of southernmost Norway from long-range atmospheric transport. Moss biomonitoring at regular intervals since 1977 show substantially decreasing deposition over time for these metals, but levels in natural surface soils are still far above normal levels in the south. Concentrations of Pb in vascular plants have decreased at similar rates as shown in the moss, whereas Zn and Cd contents maintain a more constant level due to root uptake from the contaminated soil. Hg levels in moss and natural surface soil show little temporal and spatial variation, and may be mainly affected by net deposition of hemispheric Hg0.

Keywords

• Heavy metals
• long-range transport
• moss biomonitoring
• surface soil
• temporal trends