A non linear model approach to define priority for air quality control

In this work a source-apportionment approach is presented and applied in order to define priority on emission control strategies to limit PM10 concentrations in atmosphere. Emission control priority is defined starting from the results of the application of the source-apportionment module of the CAMx chemical transport model. The module, based on reactive tracers approach, allows to take into account the effect of the heavy non linearity affecting the formation and accumulation of PM10 in the atmosphere. The methodology has been applied on Northern Italy, a region often affected by high PM10 levels both in cold and warm season. The application results are presented in two different steps. In the first one, the validation of the overall CAMx model is presented, in terms of its capability to describe the phenomena involved in PM10 accumulation and formation. The second step concerns the application of the model to define priority on PM10 control actions. The validation results show high performances both in terms of mean values and other statistical indexes, with correlation around 1 and normalized errors close to 0 for almost all the considered validation stations. The source-apportionment methodology application highlights that control of emissions due to domestic heating, transport, agriculture and industrial processes is the main priority for a decision maker, accounting for the 70% of the PM10 levels.