Influence of geological setting and exposure age on aerosols onthe surface of spruce needles

Abstract

The mass and the elemental composition of aerosols adhering to the surface of Norway spruce needles (Picea abies Karst.) were investigated at 5 sites, which differ in their geological setting (flysch, limestone, quartzite, granite and moraines). Of these sites 4 are in remote areas with only small nearby anthropogenic sources, and one is near to an industrial area. Sampling was done by needle age class from the upper third of the crown of dominant trees. Aerosols were removed from the needle surface by dissolution of the epicutictllar wax layer with an organic solvent. Analysis was done by instrumental neutron activation, giving quantitative information on 29 elements.The influence of the different geological setting of the sites and of the different exposure age ofthe needles on the mass and on the chemical composition of the aerosols are discussed.