title: Mass and ionic composition of atmospheric fine particles over Belgium and their relation with gaseous air pollutants.
abstract: Mass, major ionic components (MICs) of PM2.5, and related gaseous pollutants (SO2, NO(x), NH3, HNO2, and HNO3) were monitored over six locations of different anthropogenic influence (industrial, urban, suburban, and rural) in Belgium. SO4(2-), NO3-, NH4+, and Na+ were the primary ions of PM2.5 with averages diurnal concentrations ranging from 0.4-4.5, 0.3-7.6, 0.9-4.9, and 0.4-1.2 microg m(-3), respectively. MICs formed 39% of PM2.5 on an average, but it could reach up to 80-98%. The SO2, NO, NO2, HNO2, and HNO3 levels showed high seasonal and site-specific fluctuations. The NH3 levels were similar over all the sites (2-6 microg m(-3)), indicating its relation to the evenly distributed animal husbandry activities. The sulfur and nitrogen oxidation ratios for PM2.5 point towards a low-to-moderate formation of secondary sulfate and nitrate aerosols over five cities/towns, but their fairly intensive formation over the rural Wingene. Cluster analysis revealed the association of three groups of compounds in PM2.5: (i) NH4NO3, KNO3; (ii) Na2SO4; and (iii) MgCl2, CaCl2, MgF2, CaF2, corresponding to anthropogenic, sea-salt, and mixed (sea-salt + anthropogenic) aerosols, respectively. The neutralization and cation-to-anion ratios indicate that MICs of PM2.5 appeared mostly as (NH4)2SO4 and NH4NO3 salts. Sea-salt input was maximal during winter reaching up to 12% of PM2.5. The overall average Cl-loss for sea-salt particles of PM2.5 at the six sites varied between 69 and 96% with an average of 87%. Principal component analysis revealed vehicular emission, coal/wood burning and animal farming as the dominating sources for the ionic components of PM2.5.
authors.affiliation: Micro and Trace Analysis Centre, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
authors.forename: László
authors.initials: L
authors.lastname: Bencs
authors.forename: Khaiwal
authors.initials: K
authors.lastname: Ravindra
authors.forename: Johan
authors.initials: J
authors.lastname: de Hoog
authors.forename: Elise Octavie
authors.initials: EO
authors.lastname: Rasoazanany
authors.forename: Felix
authors.initials: F
authors.lastname: Deutsch
authors.forename: Nico
authors.initials: N
authors.lastname: Bleux
authors.forename: Patrick
authors.initials: P
authors.lastname: Berghmans
authors.forename: Edward
authors.initials: E
authors.lastname: Roekens
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Krata
authors.forename: René
authors.initials: R
authors.lastname: Van Grieken
mesh_terms: D000336:Aerosols / Q000032:analysis / Q000737:chemistry; D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D000838:Anions / Q000032:analysis / Q000737:chemistry; D001530:Belgium; D016000:Cluster Analysis; D004784:Environmental Monitoring; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis* / Q000737:chemistry; D012621:Seasons; D012623:Seawater / Q000737:chemistry; D012965:Sodium Chloride / Q000032:analysis / Q000737:chemistry; D013455:Sulfur / Q000032:analysis / Q000737:chemistry; D014887:Weather
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D000838:Anions; D052638:Particulate Matter; D012965:Sodium Chloride; D013455:Sulfur; D009584:Nitrogen