APICE: a detailed picture of the contribution of harbour emission sources to the PM2.5 concentration in each study area has been assessed.

The first specific objective of APICE was to estimate the relative contribution of several pollution sources to air quality and to understand the similarities/differences among the port areas investigated. This task has been carried out by the scientific groups following two different techniques of Source Apportionment analysis, based respectively on receptor models, more suitable to pointing out the bonds between specific emission sources and specific markers, and Chemical Transport Models (CTMs) that extend their assessment on the formation of secondary aerosols, since they apportion the gas precursor emissions, too. The focus of these techniques was the identification of pollutant emissions that mostly affect PM10 and PM2.5 concentrations.

The higher contribution of harbour activities, in terms of ships emissions and related port activities, such as induced road traffic and load/unload operations, etc., has been estimated in summer in Barcelona at the very heart of the port and in Thessaloniki at open sea (both over 50% of contribution), whereas in the other cities lower values have been estimated. Nevertheless at urban background sites more comparable results have been obtained with a contribution ranging from 2% to 17% in summer and 0% to 7% in winter.

The maritime contribution among the city partners is quite different, depending not only on the peculiarity of each study area (e.g.: socio-economic trends, meteorological and dispersion conditions, industrial and residential emission strength and composition), but also from the methodology applied by the partners.

A common feature for the five study areas is an higher contribution during the summer period, when touristic ship activities are at their maximum and residential heating is at its minimum.

Details on the source apportionment are available in the publication:   " Reducing atmospheric pollution in the Mediterranean Port Cities - The results of APICE project"