The origin of the ionic atmospheric particulate matter in a southern Mediterranean city by method cross-checking

Abstract

Abstract In order to trace the origin of the atmospheric Particulate Matter (PM10 and PM2.5) and their water-soluble ionic components, the airbone particles were first collected on PTFE filters than analyzed by ion chromatgoraphy at different sites in the southern Mediterranean city of Tunis (Tunisia) where very rare studies on air pollution are available. These analysis allowed the calculation of the matrix of correlation, the neutralization factors, the ions ratio values and the ionic temporal variation essentially during a sand storm for three different sites: Traffic, Industrial and Urban Background sites. The innovative cross-checking of the various calculations confirm the non-marine origin of K+, Ca2+ and SO42−: soil dust origin of K+ and Ca2+, and combustion origin of SO42−. The Na+ and Cl− have pure marine origin, whereas Mg2+ has mainly a marine and slightly a crustal origin. NO3− and NH4+ have an anthropogenic origin, either from combustion and/or industrial origin. The acidic ions were essentially neutralized by NH4+ and Ca2+.