A NOTE ON SMOKE CONCENTRATIONS IN URBAN ATHENS, USING DATA MEASURED BY 2 DIFFERENT METHODS

The relationships between smoke concentrations, measured at two monito ring stations in Athens by the ASTM (American Society for Testing and Materials) and the OECD (Organization for Economic Co-Operation and De velopment) methods are studied by using a sample of 738 mean daily val ues of simultaneous measurements during the period 1984-1986. It is sh own that an exponential model, different for each monitoring station, with smoke concentrations in COH (coefficient of haze) as the independ ent variable and smoke concentrations in mugr/m3 as the dependent vari able, was the most appropriate for transforming smoke data from COH to mugr/m3. Also it is shown that the transformation models can be appli ed independent of the prevailing meteorological conditions. Finally so me tentative conclusions are derived concerning the long term variatio ns of smoke concentrations in mugr/m3 for the period 1977-1990 and 197 3-1990 at the two monitoring stations respectively. The trend analysis has shown that pollution abatement efforts resulted in an about 10% p er year decreasing trend in smoke concentrations, during the period 19 86-1990, at these two Athenian stations.