Air quality over Portugal: now and in 2050

Abstract

The air quality standards guidelines defined by the World Health Organization, continues to be much more exigent than the actual EU legislation, namely regarding the main critical pollutants over Europe: ozone (O-3) and particulate matter (PM10 and PM2.5). This work intends to evaluate the fulfilment of these standards in the present and in the future, including climate change (CC) effects. This study will be focused on the region of Portugal, where each year PM10 concentrations are exceeding the legislated limit values. For that, regional air quality simulations for present and future periods were conducted, with CAMx, to investigate the impacts of CC and anthropogenic emission projections on air quality over Portugal in 2050. The climate and the emission projections for 2050 were derived from the RCP8.5 scenario. Modelling results indicate serious health impacts due to PM airborne concentrations for both long-term and short-term exposure. The annual averages for both PM10 and PM2.5 exceed the air quality standard (AQS) throughout the country. The PM short-term exposure is already very high for present-day conditions and higher impacts are expected for future scenarios in particular regarding the PM10 values. This is justified by the warmer and dryer conditions and the increase of background concentrations of pollutants in future climate. The results evidence that urgent air quality management strategies need to be designed, considering transboundary cooperation and implementation.