Geochemistry of PM10 over Europe during the EMEP intensive measurement periods in summer 2012 and winter 2013.

The third intensive measurement period (IMP) organised by the European Monitoring and Evaluation Programme (EMEP) under the UNECE CLTRAP took place in summer 2012 and winter 2013, with PM₁₀ filter samples concurrently collected at 20 (16 EMEP) regional background sites across Europe for subsequent analysis of their mineral dust content. All samples were analysed by the same or a comparable methodology. Higher PM₁₀ mineral dust loadings were observed at most sites in summer (0.5-10 µg m^-3) compared to winter (0.2-2 µg m^-3), with the most elevated concentrations in the southern- and easternmost countries, accounting for 20-40% of PM₁₀. Saharan dust outbreaks were responsible for the high summer dust loadings at western and central European sites, whereas regional or local sources explained the elevated concentrations observed at eastern sites. The eastern Mediterranean sites experienced elevated levels due to African dust outbreaks during both summer and winter. The mineral dust composition varied more in winter than in summer, with a higher relative contribution of anthropogenic dust during the former period. A relatively high contribution of K from non-mineral and non-seasalt sources, such as biomass burning, was evident in winter at some of the central and eastern European sites. The spatial distribution of some components and metals reveals the influence of specific anthropogenic sources on a regional scale: shipping emissions (V, Ni, and SO₄^2-) in the Mediterranean region, metallurgy (Cr, Ni, and Mn) in Central and Eastern Europe, coal combustion (As, Se, and SO₄^2-) in Eastern countries, and traffic (Cu) at sites affected by emissions from nearby cities. [ABSTRACT FROM AUTHOR]