aerosol size segregated of tehran's atmosphere in iran

tehran is located in a valley at the foot of the alborz mountains in northern iran (35 degrees latitude north). urban expansion in tehran resulted from a high rate of population growth and rural-urban migration combined with a strong tradition of centralization in the capital. airborne particulate of tehran&apos;s atmosphere was fractionated in a 6-stage high-volume cascade impactor. the first objective was to measurement of pm in twenty sites in tehran areas. other objectives were to obtain detailed measurements of aerosol size distribution in tehran&apos;s atmosphere during the 2004 at five sites. in all samples the pm is high for stage 6 (< 0.49 î¼m). in enghelab station mean of pm value (< 0.49 î¼) is 260.97 î¼g/m3. the highest pm (10-7 î¼m) concentration is found 115.12 î¼g/m3 at the enghelab station. and the highest pm (3-1.5 î¼m) was found 40.5î¼g/m3 at the baseej site.