Seasonal chemical and mineralogical variability of atmospheric particles in the coastal region of the Northeast Mediterranean

A time-serial analysis of atmospheric particles collected since 1990 at a coastal site bordering the northeastern Mediterranean Sea shows that the collected samples, display seasonal patterns in both concentration and color. The 1990–91 and 1992 collections yield an annualised average of around 0.5 g/day dust loading reducing to around 0.3 g/day when the sea-salt contribution is excluded. The highest concentrations of atmospheric particles of continental origin for both natural (e.g. Fe, Mn) and anthropogenic (e.g. Cd, Pb) materials are observed between April and October and this variability is inversely related to the frequency and the amount of rainfall. Sea-salt aerosol (Na) contents do not follow this pattern but are related to local wind speeds. elements in the dusts also display seasonal variations in enrichment factors (EF), with respect to average elemental abundances in crustal rocks. The non-enriched (crustal) elements appear to be indicators of long-distance supply while the strongly enriched (anthropogenic) and moderately enriched suites of elements represents inputs from local or “anomalous” sources. milar morphology of quartz and calcite grains and the uniformity of the clay mineral assemblages in samples collected over a two-year period strongly indicate a common source for the bulk of the atmospheric particles. The dominant clay types (palygorskite and smectite) document a desertic source areas.