Estimation of North African dust contribution on PM10 episodes at four continental Greek cities

African dust intrusions in the atmosphere of continental Greek cities have been previously associated with health impacts. This paper aimed to estimate the participation of Saharan dust in PM10 episodes which occurred in four cities of continental Greece: Athens, Thessaloniki, Larisa and Ioannina, during the years 2012-2017. Exceedances of the European Union (EU) daily PM10 concentration limit at background sampling sites situated in the four cities were examined for possible dust contributions with Dust Regional Atmospheric Model (DREAM). The participation of regional background emissions and dust in PM10 Dust Related Exceedances (DRE) was estimated by an approach based on the daily PM10 concentrations measured 15 days before and 15 days after the Saharan dust event. The average dust contribution in DRE was higher in Athens in comparison with the other cities. In addition, backward air mass trajectories indicated that the great majority of the studied DRE was triggered by direct dust intrusions from North Africa, whereas some rare cases of dust recirculation were also detected. All the studied DRE at the four cities wouldn't have occurred without the presence of the African dust, thus the suggested approach could be a fast and inexpensive tool in order to isolate the reduced actual number of exceedances attributed to local/regional emissions. Consequently, air quality management can be simplified through the implemented method.