The air quality monitoring programme in Rijeka started in early seventies and has been oriented to air pollution caused by the big industrial sources (new petroleum refinery, oil burning power plant, coke plant), while maritime traffic was neglected. First emission inventory comprising port emission was done only in 2008 indicating similar level of emissions as road traffic. Further analyses on maritime impact on air quality were done within MED project POSEIDON. This was the good opportunity to perform Positive Matrix Factorization (PMF) analysis on airborne particulate data and identify principal sources of pollution within the Rijeka urban area. PMF analyses of PM10 collected from the urban background site in the period 2008- 2010 identified 5 factors: biomass burning, secondary inorganic aerosols (SIA), sea spray, dust and metal industry/traffic. Condition probability functions (CPF) obtained from PMF factors of dust and SIA indicate that Ca, Fe, Zn and Cu originate from harbour area due to reloading of fertilizers and metal waste, as well as SO42-and NH4+ pointing to maritime corridor leading to the Rijeka harbour. These data could not quantify the maritime impact, but this was done estimating primary PM2.5 emission from ships based on the airborne concentration of vanadium obtained in other part of the project and showing a decline from 2008 to 2012, due to reduced economic activities during period of crisis. Similar declining trend is observed in PAHs profiles confirming diminished diesel fuel combustion in the same period.