A model for calculation of population exposure to air pollution is developed. With the aid of an existing dispersion model, SO2 and NOx concentrations are calculated in a network of gridpoints covering the Greater Stockholm area. Emissions from traffic and stationary sources are treated in the model. A simple model is constructed in order to improve the population data initially given. It is thereafter possible to take into account exposure at work as welI as at home for the working part of the population.