Chemical characterization and source apportionment of PM₁₀ in Belgrade, Serbia: influence of local and regional anthropogenic and natural sources

Abstract. Substantial efforts and improvements in air quality across Europe lowered levels of air pollutants including particulate matter (PM) in the last decades. However, significant proportion of the European population still lives in areas exceeding WHO recommendations, especially in Northern Italy, Balkans and Eastern Europe, including Serbia. Targeted PM mitigation strategies require extensive air quality monitoring and modelling including source apportionment (SA) studies. In the past, numerous SA studies were conducted for Belgrade city, capital of Serbia. Nevertheless, comparisons across the results are difficult, as they encompass different datasets of pollutants contained in PM fractions such as elements and/or ions and/or PAHs. Here, the aim is to offer a broader insight on PM₁₀ sources at an urban background site in Belgrade by including 34 species as input variables for SA (carbonous aerosols, elements, ions and specific organic tracers). For SA, the USEPA PMF 5.0 software was applied. The factor that dominated PM₁₀ mass was biomass burning (21%), primarily during heating season, followed by ammonium sulphate (18%) and mineral dust (17%). A mixed traffic and industrial activity accounted for 15% of PM₁₀ mass while contribution of factors from biological origin, primary biological aerosol particles and biogenic secondary organic aerosols from isoprene, was 10% each. Mixed factor of long-range transport and road salt/local combustion contributed to the PM₁₀ mass 9%. This analysis provides more detailed perspective on the composition and sources of PM₁₀ in Belgrade, both from anthropogenic and natural, including biological origin. These findings are valuable for defining targeted PM₁₀ mitigation strategies.