Carbonaceous aerosols in industrial and coastal atmospheres

Abstract

Total suspended and size-segregated aerosol samples were collected at one industrial and one coastal location. Measurements of inorganic ions, trace elements and organic/elemental carbon (OC/EC) permitted us to conclude that at the marine site most carbonaceous mass is associated with vehicle emissions and long-range transport, being well correlated with lead. At the industrial location the picture is not so clear because lead is also emitted by local industries. A good correlation, however, exists for EC between both sites, indicating that elemental carbon is well mixed in the lower troposphere and has a regional character. EC and OC frequently have a bimodal size distribution, each mode being approximately log-normal. At both sites ≈ 78% of EC and 68-76% of OC are in the fine-particle mode fraction. High levels of elemental carbon are present in aged polluted air masses transported from industrialized regions in Europe. These air masses contain relatively much less particulate organic carbon. During long-range transport the organic constituents of the aerosol are depleted while elemental carbon is transported efficiently. © 1993.