SOURCE ASSESSMENT OF PARTICULATE AIR-POLLUTANTS MEASURED AT THE SOUTHWEST EUROPEAN COAST

Aerosol particles and gaseous species were measured in air masses tran sported to the west coast of Portugal, between November 1993 and Augus t 1994. Samples were taken during four monitoring campaigns distribute d along the various seasons of the year, integrated in the EC Project: BMCAPE. Aerosol particles were collected with separation in two size fractions and analysed in relation to total mass, water soluble ions, trace elements and black/organic carbon. Local micro-meteorological pa rameters and air mass backward trajectories were compared with analyti cal results in order to define characteristic air mass types and to ev aluate the origin of pollutants. Average concentrations on the Portugu ese west coast, even in maritime air masses, are higher than values ob served in remote oceanic locations. This is probably a consequence of continental European air masses recirculation through the eastern Atla ntic Ocean, reinforced by situations of mesoscale transport from the I berian Peninsula. Principal Component Analysis permitted the identific ation of five source groups for the fine and coarse aerosol fractions, namely combustion plus road traffic, sea salt spray, secondary aeroso l production, soil and possibly non-ferrous metallurgy industries. Ln the aerosol fine fraction road traffic and combustion contribute on av erage with 25% of the total fine aerosol mass, while sea spray and sec ondary production represent 14% and 31%, respectively of the mass load ing. Sea spray is by far the major contributor to the coarse fraction with an average of 88% of the suspended coarse aerosol mass. Copyright (C) 1996 Elsevier Science Ltd