TRACE-ELEMENTS IN DAILY COLLECTED AEROSOLS AT A SITE IN SOUTHEAST ENGLAND

Daily collections of aerosols have been made at a site in southeast England over a 1 year period and the samples analyzed for 13 components including soot carbon, major anions, some major cations and five trace metals (Pb, Cd, Zn, Mn and Ni). The results are consistent with other more limited studies in the southern North Sea and can be used to tentatively identify primary and secondary sources for the components of the aerosol. Elemental ratios for some components derived from anthropogenic sources vary slightly depending on the source region over which the air has recently travelled. Classification of the samples by back trajectory analysis shows that for all components, except those derived from seawater, concentrations are highest in air arriving from the east. This observation is discussed in terms of meteorological control on the transport and deposition of aerosols. Specifically, high pressure over Europe allows the accumulation of pollutants through reduced atmospheric dispersion and limited removal by precipitation. Subsequent long-range transport results in high concentrations of aerosols at the sampling site. By contrast, transport from the west is associated with efficient dispersal and removal processes.