Association between a socio-economic variable and exposure to air pollution for high resolution census data in Scania, Sweden.

How human exposure levels of air pollutants are related to health status is an issue of great importance for e.g. infrastructural and urban planning. This study analysed the exposure levels of NO2 for individuals depending on their country of birth. The study was conducted within three different study areas of varying characteristics and extent to decide whether any such associations existed and if the relations seen were affected by the choice of study area. To perform this study we used high-resolution census data and modelled the annual exposure to NO2 using an emission database, a dispersion modelling program and a GIS. The study group was divided into county level and also for two major cities in Scania.

The result of this study strongly indicates that there is an association between an individuals county of birth and NO2 concentration level. The exposure to air pollutants for the different socio-economic groups varied significantly between the areas studied, and the relationships seen differed, not only in magnitude but also in direction. For the county of Scania the results indicated that the area was heterogeneous regarding the association between air pollution and socio-economic status. However, the relationship differed when the analysis was performed on city level. The main conclusions are that it is unwise to analyse and establish associations between socio-economic factors and exposure to air pollutants on county level, and that the size and choice of study area is of great importance.