The nationwide dataset of PM chemical speciation of Italy: lighting-up the influence of local geographical differences on urban PM

Chemical speciation of airborne particulate matter (PM) may be influenced by topographic peculiarities. This is commonly observed in Italy: PM composition at urban sites may largely differ, due to local geography. In this work, linkages between local territory and urban PM composition differences are explored nationwide, and PM chemical fingerprints are discussed versus anthropic impact and local geography. Under the initiative of WG1 -Sources and formation processes of aerosol of the Italian Aerosol Society (IAS), a nationwide dataset was built, including PM10 and PM2.5 chemically speciated data (2005 – 2016) from 23 urban sites (large cities, ports, medium inland cities) in Italy. By factor analysis, 12 factor-fingerprints were identified: ports activities, farming, dust transport, traffic exhausts, road dust, sea spray, biomass burning/other combustion, secondary sulphate, discriminated by specific urban type (i.e. farming only relates to cities in Po Valley), and/or anthropic strength (i.e. traffic exhausts in large / small cities).