Atmospheric aerosol and gaseous species in Athens, Greece

Measurements of aerosol species including Cl-, NO-3, SO2-4, NH+4, Na+, K+, Mg2+ and Ca2+ and gaseous pollutants like HCl, HNO3, NO2, SO2 and O3 were conducted at the centre of Athens. Results show moderate levels of pollution with aerosol species typical of dust emissions and secondary aerosol of anthropogenic origin. Most gaseous pollutants correlate well with aerosol species. There is a pronounced elevation in the concentration of acidic trace gases HCl and HNO3 arriving at the city from the direction of the Saronikos gulf, indicating poor neutralisation of such species over the sea. On the contrary, air masses coming from inland are characterised by considerably higher ammonium aerosol. It was concluded that in addition to heavier aerosol load pollution episodes in Athens during the summer period are associated with higher concentrations of gaseous acids.