title: Biomass burning contributions to urban aerosols in a coastal Mediterranean city.
abstract: Mean annual biomass burning contributions to the bulk particulate matter (PM(X)) load were quantified in a southern-European urban environment (Barcelona, Spain) with special attention to typical Mediterranean winter and summer conditions. In spite of the complexity of the local air pollution cocktail and the expected low contribution of biomass burning emissions to PM levels in Southern Europe, the impact of these emissions was detected at an urban background site by means of tracers such as levoglucosan, K(+) and organic carbon (OC). The significant correlation between levoglucosan and OC (r(2)=0.77) and K(+) (r(2)=0.65), as well as a marked day/night variability of the levoglucosan levels and levoglucosan/OC ratios was indicative of the contribution from regional scale biomass burning emissions during night-time transported by land breezes. In addition, on specific days (21-22 March), the contribution from long-range transported biomass burning aerosols was detected. Quantification of the contribution of biomass burning aerosols to PM levels on an annual basis was possible by means of the Multilinear Engine (ME). Biomass burning emissions accounted for 3% of PM(10) and PM(2.5) (annual mean), while this percentage increased up to 5% of PM(1). During the winter period, regional-scale biomass burning emissions (agricultural waste burning) were estimated to contribute with 7±4% of PM(2.5) aerosols during night-time (period when emissions were clearly detected). Long-range transported biomass burning aerosols (possibly from forest fires and/or agricultural waste burning) accounted for 5±2% of PM(2.5) during specific episodes. Annually, biomass burning emissions accounted for 19%-21% of OC levels in PM(10), PM(2.5) and PM(1). The contribution of this source to K(+) ranged between 48% for PM(10) and 97% for PM(1) (annual mean). Results for K(+) from biomass burning evidenced that this tracer is mostly emitted in the fine fraction, and thus coarse K(+) could not be taken as an appropriate tracer of biomass burning.
authors.affiliation: Institute of Environmental Assessment and Water Research, IDAEA, CSIC, c/ Jordi Girona 18-26, Barcelona, Spain. cristina.reche@idaea.csic.es
authors.forename: C
authors.initials: C
authors.lastname: Reche
authors.forename: M
authors.initials: M
authors.lastname: Viana
authors.forename: F
authors.initials: F
authors.lastname: Amato
authors.forename: A
authors.initials: A
authors.lastname: Alastuey
authors.forename: T
authors.initials: T
authors.lastname: Moreno
authors.forename: R
authors.initials: R
authors.lastname: Hillamo
authors.forename: K
authors.initials: K
authors.lastname: Teinilä
authors.forename: K
authors.initials: K
authors.lastname: Saarnio
authors.forename: R
authors.initials: R
authors.lastname: Seco
authors.forename: J
authors.initials: J
authors.lastname: Peñuelas
authors.forename: C
authors.initials: C
authors.lastname: Mohr
authors.forename: A S H
authors.initials: AS
authors.lastname: Prévôt
authors.forename: X
authors.initials: X
authors.lastname: Querol
mesh_terms: D000336:Aerosols / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D018533:Biomass; D002244:Carbon / Q000032:analysis*; D002947:Cities; D004784:Environmental Monitoring; D005390:Fires; D005947:Glucose / Q000031:analogs & derivatives* / Q000032:analysis; D008954:Models, Biological; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis; D011188:Potassium / Q000032:analysis*; D012621:Seasons; D013030:Spain; D014934:Wood
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D015415:Biomarkers; D052638:Particulate Matter; C014989:1,6-anhydro-beta-glucopyranose; D002244:Carbon; D005947:Glucose; D011188:Potassium