Estimation of secondary organic aerosol (SOA) production from traffic from the city of Athens

Estimates of the amount of secondary organic aerosol formed in the atmosphere from the degradation of
traffic C6-C12 hydrocarbon emissions in the city of Athens are presented. Around 1.26 tn of organic aerosol
is estimated to be produced during a six hours air pollution episode from the aromatic hydrocarbons,
the other NMHC groups contributing an additional 0.2 tn. The main contributor to the SOA production is
m-xylene. It accounts, together with toluene, for around 50% of the produced organic aerosol. The main
aerosol products that are expected to form from the Athens NMHC traffic mixture are nitrophenols. Due
to predominant wind flow to the S-SE direction in the area, a portion of these aerosols is likely to contribute
to the SOA burden of the marine atmosphere over SE Mediterranean. These results are also relevant to
ozone abatement strategies involving species-specific NMHC reductions and affecting fine particulate
composition and concentrations.