PARTICULATE AND GASEOUS AIR POLLUTANT LEVELS AT THE PORTUGUESE WEST-COAST

A field study was conducted at a coastal site near Aveiro, Portugal, where inorganic compounds and trace elements were measured on the atmospheric suspended aerosol, and nitric acid, hydrochloric acid and ammonia detected in the gaseous phase. The levels of hydrochloric and nitric acids were of the same order of other values detected on non-urban sites in industrialized Europe. The concentrations of aerosol constituents were higher than would be expected for a region located on the western corner of the European continent. The existence of high pressure conditions over Western Europe and the Iberian Peninsula during most of the sampling period, with persistence of stagnant air masses and slow transport from the continent can be an explanation for the observed values. Principal Component and Cluster Analysis permitted the detection of six aerosol source groups, five regional (namely soil emission, transport, oil combustion, secondary pollutants and sea spray), and one, possibly local, that could not be identified with precision.