PARTICULATE MATTER LESS-THAN-10 MU-M (PM(10)) AND TOTAL SUSPENDED PARTICULATES (TSP) IN URBAN, RURAL AND ALPINE AIR IN SWITZERLAND

Ambient concentrations of particulate matter of less than 10 mu m aero dynamic diameter were measured in Switzerland for a 1 yr period in 199 3 at a dozen urban, rural and alpine sites. PM(10) concentrations rang ed between 10 mu gm(-3) (alpine) and 33 mu gm(-3) (urban). Highest con centrations were found at Lugano, in the south of the Alps, and in urb an sites of the Swiss Plateau (350-670 m.s.l.). Rural levels were one- third lower than the urban levels and relatively homogeneously distrib uted. Alpine sites showed considerably lower levels. The ratios betwee n PM(10) and TSP were found to be between 0.6 and 0.75, and the highes t ratios were found in the most polluted urban sites. Seasonal variati on of particulate pollution showed peak levels during winter and autum n, mainly during cold temperature-inversions. Statistical analyses hav e shown a good correlation between PM(10) and NO2 and SO2, and TSP in urban areas.