Traffic and residential wood combustion (rwc) constitute the two dominating local sources to fine particulate matter PM2.5 concentration levels in Sweden. In order to meet the authorities’ requirements of air quality assessments, a national modelling system SIMAIR has been developed. The system is based on the commercial Airviro air quality management software, a three tier client/server/web system which includes modules for measurement data collection, emission databases and dispersion models with very high performance in terms of data access and model execution. The technical characteristics of Airviro databases and models have facilitated web based national air quality systems, of which some examples are given.The present Airviro/SIMAIR application had the objective to assess the impact of rwc in three urbanized areas in northern Sweden. The Airviro Scenario module was used to determine exposure and health impact of the rwc contribution. The estimated mortality due to PM2.5 concentrations from residential wood combustion is about 4 persons/year, which corresponds to approximately 0.4% of the total number of deaths (excluding accidents). Cities which have well established district heating facilities have a lower rwc use and a very different exposure to locally generated PM2.5. Umeå, one of the three areas in the study, is such a city. A similar assessment with impact only from traffic emissions shows an increase of 4.4 deaths for the Umeå population, while the impact of wood combustion in the city contributes with 2.5 deaths per year. The advantages of using the Airviro software in combination with annually updated databases for input data on the national scale, are summarized. The approach facilitates for municipal end users and non-meteorological professionals like epidemiologists to perform by themselves advanced dispersion simulations and health impact assessments.