Variations of Particulate Matter Concentrations and Particle-Associated Substances in Latvia

Concentrations of air pollutants mainly depend on meteorological conditions and pollutant emission levels. Airborne particulate matter (PM_2.5 and PM₁₀) concentrations were measured in Riga (Latvia) from the end of April to the end of December 2007. The collected particulate matter was analyzed for the anion, cation and heavy metal content. The seasonal variations of particulate matter concentrations were investigated, together with their relationships with meteorological parameters and other pollutant gases. The maximum daily concentration of PM_2.5 and PM₁₀ reached 52.5 μg/m³ in June and 83.4 μg/m³ in December, respectively.