We performed field measurements of fine particulate matter PM2.5; used laboratory measurements of PM chemical composition for collected filter samples; performed source apportionment of PM2.5 to elucidate their emission sources, ambient processing and determine the effects on health through oxidative potential measurements. The data was analyzed and the database stored in a central and publicly available database.
SAAERO field measurements were conducted at the Bjelave supersite in Sarajevo, B&H from August 2022 through March 2023. Bjelave sampling site is located at the headquarters of the Federal Hydrometeorological Institute of B&H. This sampling site is an urban background site located within a mainly residential and densely populated part of the Sarajevo. High Volume Air Sampler was installed at Bjelave sampling site for collection of continuous, daily samples on quartz filters. Field measurements of PM2.5 included on-line, high-time resolution measurements of total carbon, black carbon (BC) with s Total Carbon Analyzer TCA08 and an Aethalometer AE33, respectively. Two state-of-the-art online instruments for monitoring of aerosol properties in real time were added to originally proposed instrumentation: Quadrupole Aerosol Chemical Speciation Monitor for determination of bulk aerosol chemical composition; and Xact 625i ambient metals monitor for determination of aerosol elemental composition. During SAAERO field measurements, the PSI mobile laboratory performed mobile and stationary measurements.
Filter-collected aerosol samples were shipped to IGE where they underwent the following laboratory analyses: OC/EC with thermal-optical analysis (EUSAAR2 thermal-optical protocol); inorganic anions (nitrate, nitrite, sulphate, and chloride) and cations (ammonium, sodium, potassium, calcium, magnesium and fluoride), and many tracer organic species; anhydrous monosaccharides (levoglucosan, mannosan and galactosan) and polyols; trace metals; and oxidative potential of PM in simulated lung fluid by two assays (DTT, AA). Off-line measurements were compared to on-line ones.
Q-ACSM measurements at the Bjelave site during the SAAERO field campaign determined bulk chemical composition of PM1. Averaged over the entire period of SAAERO field measurements, OA made up the majority of ambient aerosol mass loadings (60%), followed by sulphate (24%), nitrate (10%), ammonium (5%) and chloride (1%). Source apportionment of OA data from Q-ACSM resulted in three factors: hydrocarbon-like OA (HOA) (25% of total OA), oxygenated OA (OOA) (33%) and biomass burning OA (BBOA) (42%). Source apportionment of OA from the PSI mobile laboratory AMS revealed six factors. In addtion to the Q-ACSM factors, a cooking factor and a factor related to coal burning. To apportion the sources of the elemental fraction of PM2.5 we used highly time-resolved elemental composition data from Xact 625i in the winter period. Six sources of PM2.5 elements were identified: fireworks (1%), dust (2%), heavy oil / regional (33%), industrial (20%), traffic (4%) and biomass, aged and fresh (40%). BC concentrations in Sarajevo increased toward colder months due to increased biomass burning emissions and more stable conditions in the planetary boundary layer. Increased biomass burning contribution is evident from source apportionment analyses of BC and is much higher in Sarajevo (47 %) than other capitals in the region.
