The weekly average aerosol mass and composition were measured for a year at 5 altitudes (between 450 and 1780 m a.s.l.) using low-volume filter devices. A pronounced altitude dependence for total suspended particulate matter (TSP) and major ions was found in winter periods due to the poor vertical air exchange. For selected winter periods, six-stage low pressure impactors were employed. No differences in the size distribution of the aerosol composition could be detected at different altitudes. The influence of fog as well as local emission sources is also presented.