SUBMICROMETER PARTICLE-SIZE DISTRIBUTION FROM 0.1-0.45-MU-M IN THE URBAN PLUME OF THE CITY OF VALLADOLID

Particle size distribution in the urban plume of the city of Valladoli d was measured with a laser spectrometer during a one-month sampling c ampaign carried out over the winter period. Experimental results of th e number of particles covering the 0.10-0.12, 0.12-0.15, 0.15-0.20, 0. 20-0.25, 0.25-0.35 and 0.35-0.45 mum ranges are presented. Using spect ral analysis as a statistical technique, two 12 h and 24 h significant peaks are obtained for each size range. In order to interpret the mea ning of both peaks, the hourly particle size, traffic and nitrogen oxi de patterns are compared. The contribution of domestic heating, traffi c exhaust emissions and the strong influence of the gas-to-particle co nversion processes mainly within the 0.10-0.15 mum range, may be infer red.