CHEMICAL-COMPOSITION OF WET AND DUST DEPOSITION IN ATHENS, GREECE

In the present study a wet/dry precipitation collector was used (Canadian MIC) to collect wet and dust deposition samples in one station in the center of the Athens basin, Greece, for the period September 1987-August 1988. Concentrations of the main cations (H+, NH4+, Na+, K+, Ca2+ and Mg2+) and main anions (Cl-, NO3- and SO42-) were determined. The analytical chemical methods were evaluated with NBS standard reference material and with rainwater samples from EMEP (European Monitoring Evaluation Programme). Statistical analyses of correlation between the concentration of chemical species and correlation diagrams between chemical species concentrations and wind directions were made in order to estimate the origin of the determined ions both in wet and dust deposition. In all samples non-marine molar sulfate concentrations exceed nitrate concentrations despite the dominance of low sulfur oil burning in the region (0.3% for domestic heating, 0.7% for industrial uses). For 37% of the samples the pH was lower than 4.5 and for 69% of samples was lower than 5.6. The wet flux of sulfur was calculated to be 0.67 g m-2 yr-1. The results support the conclusion that chemical constituents in rain and dust deposition are a combination of emissions from natural and anthropogenic sources.