Applying model calculations to estimate urban air quality with respect to the requirements of the EU directives on NO2, PM10 and C6H<SUB alig

Population exposure for NO2, PM10 and C6H6 for two Norwegian cities has been estimated for the year 2001. Calculated exposure levels have been related to the EU Council Directive limit levels of air quality. A stationary population distribution has been applied in the exposure calculations and a ranking of the most important sources contributing to the exceedances has been established. Results indicate that a considerable portion of the inhabitants are exposed above the proposed limit value of PM10, while only a small fraction are above the limit value for NO2. No exceedances are found for benzene (C6H6). Furthermore, road traffic is the dominant source contributor to the NO2 exceedances, while both traffic and wood burning can be the dominant contributor for exceedance levels of PM10, depending on location within the urban area.