TRACE-ELEMENTS IN ATMOSPHERIC PRECIPITATION AT NORWEGIAN BACKGROUND STATIONS (1989-1990) MEASURED BY ICP-MS

ICP-MS has been used to study 27 trace elements in precipitation at six rural and remote sites in Norway. The work is based on weekly samples from 1989 and 1990. Element enrichment factors, based on crustal Fe, are in the order: Cd>Sb>As>Pb>Bi>Zn>Mo>Tl>Na>Cu>Be>Ni>Mg>V> U>Ga>Li>La>Sr>Cr>Mn>Rb>Ba>Th>Co>Y. The highest concentrations of elements associated with anthropogenic activities occur in northeastern Norway (Cu, Ni, Co, As) and in the southern part of the country (V, Pb, Ni, Cu, Zn, As, Mo, Cd, Sb). This is attributed to industrial activities at the Kola peninsula, Russia, and to long-range atmospheric transport from more densely populated and heavily industrialized regions in Europe. Precipitation falling over southern Norway during a single 48 h event resulted in a wet deposition of 10-20% of the annual wet deposition of most elements measured. Studies of back trajectories from this period indicate that the air masses might have passed Sahara and great parts of Central Europe before reaching Norway. Comparison of the precipitation data from Birkenes, South Norway, with data for air particles at the same sample station show that the precipitation has much higher ratios to Fe for the sea-salt elements than the aerosol has, whereas the anthropogenic elements exhibit ratios to Fe that are comparable with those in the fine aerosol fraction.