title: Organic and elemental carbon associated to PM10 and PM 2.5 at urban sites of northern Greece.
abstract: Organic carbon (OC) and elemental carbon (EC) concentrations, associated to PM10 and PM2.5 particle fractions, were concurrently determined during the warm and the cold months of the year (July-September 2011 and February-April 2012, respectively) at two urban sites in the city of Thessaloniki, northern Greece, an urban-traffic site (UT) and an urban-background site (UB). Concentrations at the UT site (11.3 ± 5.0 and 8.44 ± 4.08 14 μg m(-3) for OC10 and OC2.5 vs. 6.56 ± 2.14 and 5.29 ± 1.54 μg m(-3) for EC10 and EC2.5) were among the highest values reported for urban sites in European cities. Significantly lower concentrations were found at the UB site for both carbonaceous species, particularly for EC (6.62 ± 4.59 and 5.72 ± 4.36 μg m(-3) for OC10 and OC2.5 vs. 0.93 ± 0.61 and 0.69 ± 0.39 μg m(-3) for EC10 and EC2.5). Despite that, a negative UT-UB increment was frequently evidenced for OC2.5 and PM2.5 in the cold months possibly indicative of emissions from residential wood burning at the urban-background site. At both sites, cconcentrations of OC fractions were significantly higher in the cold months; on the contrary, EC fractions at the UT site were prominent in the warm season suggesting some influence from maritime emissions in the nearby harbor area. Secondary organic carbon, being estimated using the EC tracer method and seasonally minimum OC/EC ratios, was found to be an appreciable component of particle mass particularly in the cold season. The calculated secondary contributions to OC ranged between 35 and 59 % in the PM10 fraction, with relatively higher values in the PM2.5 fraction (39-61 %). The source origin of carbonaceous species was investigated by means of air parcel back trajectories, satellite fire maps, and concentration roses. A local origin was mainly concluded for OC and EC with limited possibility for long range transport of biomass (agricultural waste) burning aerosol.
authors: Department of Chemistry, Environmental Pollution Control Laboratory, Aristotle University of Thessaloniki, University Campus, 54124, Thessaloniki, Greece. csamara@chem.auth.gr.
authors: Constantini
authors: C
authors: Samara
authors: Department of Chemistry, Environmental Pollution Control Laboratory, Aristotle University of Thessaloniki, University Campus, 54124, Thessaloniki, Greece.
authors: Dimitra
authors: D
authors: Voutsa
authors: Department of Chemistry, Environmental Pollution Control Laboratory, Aristotle University of Thessaloniki, University Campus, 54124, Thessaloniki, Greece.
authors: Athanasios
authors: A
authors: Kouras
authors: Institute of Nuclear Technology and Radiation Protection, Environmental Research Laboratory, National Centre of Scientific Research "Demokritos", Paraskevi, Attiki, 15310, Greece.
authors: Kostas
authors: K
authors: Eleftheriadis
authors: Institute of Nuclear Technology and Radiation Protection, Environmental Research Laboratory, National Centre of Scientific Research "Demokritos", Paraskevi, Attiki, 15310, Greece.
authors: Thomas
authors: T
authors: Maggos
authors: Institute of Nuclear Technology and Radiation Protection, Environmental Research Laboratory, National Centre of Scientific Research "Demokritos", Paraskevi, Attiki, 15310, Greece.
authors: D
authors: D
authors: Saraga
authors: Environmental Department, Municipality of Thessaloniki, Paparigopoulou 7, Thessaloniki, 54630, Greece.
authors: M
authors: M
authors: Petrakakis
mesh_terms: D000336:Aerosols / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D018533:Biomass; D002244:Carbon / Q000032:analysis*; D002947:Cities; D004784:Environmental Monitoring; D005390:Fires; D006115:Greece; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons; D014934:Wood
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter; D002244:Carbon