title: Characteristics and major sources of carbonaceous aerosols in PM2.5 in Emilia Romagna Region (Northern Italy) from four-year observations.
abstract: The concentrations of organic and elemental carbon in PM2.5 aerosol samples were measured in two sites of Emilia Romagna (Po Valley, Northern Italy) in eight campaigns during different seasons from 2011 to 2014. Strong seasonality was observed with the highest OC concentrations during the cold periods (≈ 5.5 μg m(-3)) and the lowest in the warm months (≈ 2.7 μg m(-3)) as well as with higher EC levels in fall/winter (≈ 1.4 μg m(-3)) in comparison with spring/summer (≈ 0.6 μg m(-3)). Concerning spatial variability, there were no statistically significant difference (p<0.05) between OC concentrations at the two sampling sites in each campaign, while the EC values were nearly twofold higher levels at the urban site than those at the rural one. Specific molecular markers were investigated to attempt the basic apportionment of OC by discriminating between the main emission sources of primary OC, such as fossil fuels burning - including traffic vehicle emission - residential wood burning, and bio-aerosol released from plants and microorganisms, and the atmospheric photo-oxidation processes generating OCsec. The investigated markers were low-molecular-weight carboxylic acids - to describe the contribution of secondary organic aerosol - anhydrosugars - to quantify primary emissions from biomass burning - bio-sugars - to qualitatively estimate biogenic sources - and Polycyclic Aromatic Hydrocarbons - to differentiate among different combustion emissions. Using the levoglucosan tracer method, contribution of wood smoke to atmospheric OC concentration was computed. Wood burning accounts for 33% of OC in fall/winter and for 3% in spring/summer. A clear seasonal trend is also observed for the impact of secondary processes with higher contribution in the warm seasons (≈ 63%) in comparison with that in colder months (≈ 33%), that is consistent with enhanced solar radiation in spring/summer.
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17/19, I-44100 Ferrara, Italy. Electronic address: mpc@unife.it.
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Pietrogrande
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17/19, I-44100 Ferrara, Italy; Regional Agency for Prevention and Environment-ARPA, Emilia-Romagna, Italy.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Bacco
authors.affiliation: Regional Agency for Prevention and Environment-ARPA, Emilia-Romagna, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Ferrari
authors.affiliation: Regional Agency for Prevention and Environment-ARPA, Emilia-Romagna, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Ricciardelli
authors.affiliation: Regional Agency for Prevention and Environment-ARPA, Emilia-Romagna, Italy.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Scotto
authors.affiliation: Regional Agency for Prevention and Environment-ARPA, Emilia-Romagna, Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Trentini
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17/19, I-44100 Ferrara, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Visentin
mesh_terms: D000336:Aerosols / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D002244:Carbon / Q000032:analysis; D004784:Environmental Monitoring; D007558:Italy; D052638:Particulate Matter / Q000032:analysis*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter; D002244:Carbon
keywords: Carbonaceous aerosols; PAHs; Po Valley; Secondary organic carbon; Wood combustion