CONTRIBUTION OF CARBONACEOUS AND IONIC COMPONENTS OF PM_(2.5) AEROSOLS IN THE URBAN AREA OF ATHENS

摘要

This study aims to investigate the different carbonaceous components as well as the major ionic compounds in PM2.5 aerosols and their correlation in the urban area of Athens. Sampling was carried out during a two-months period in wintertime at two urban sites, with the use of a Gent Stacked filter unit collecting coarse (PM_(10-2.5)) and fine (PM_(2.5)) fractions of paniculate matter. Further analysis was focused on the fine fraction due to its potential harmful impact on human health. The chemical composition of ambient aerosols was investigated by different analytical methods. Concentrations of Total Carbon (TC), Elemental or Black Carbon (EC or BC) and Organic Carbon (OC), as well as concentrations of 8 major water-soluble ions (Na~+, NH_4~+, K~+, Mg~(2+), Ca~(2+), Cl~-, NO_3~- , SO_4~(2-)) were measured in a total of 39 samples.rnIons contributed approximately 36% to the total PM_(2.5) mass concentration. Among ions, NH_4~+, NO_3~-, and SO_4~(2-) were found in higher concentrations. Carbonaceous material (CM) accounted for 48-54% of PM2.5 at the monitoring sites. Speciation of carbon content into EC and OC was carried out with a thermal and a thermal-optical method, and an assessment of possible emission sources was performed using a statistical evaluation.