Plans and programmes to improve air quality over Portugal: a numerical modelling approach.

PM10 limit values have been surpassed in the northern region of Portugal, and, according to European legislation, Plans and Programmes (PP) must be designed and implemented to reduce those PM10 levels. The Air Pollution Model (TAPM) was applied over the study region, to the year 2004, for the reference situation with the current PM10 emissions; and, for the reduction scenario with PM10 emissions re-estimated considering the implementation of all measures, in order to investigate the impact on air quality of all PP measures. The results point to a 19% reduction in the PM10 levels over the Porto urban area. [ABSTRACT FROM AUTHOR]