At present scientific community is greatly concerned with extreme weather events due to their potential adverse effects that is associated with mesoscale weather events which can often be embedded in synoptic scale events that may be influenced by climatic variabilities. Extreme weather events can also change associated chemical compositions of the atmospheric parameters over metropolitan region. In this paper, we have used two major wind directions (N and SW) to characterize the upper and lower limits of atmospheric pollutants (PM10 and SO2) over Istanbul/Turkey rather than the wind or precipitation events that are associated with such events. In contrast to expectations, northerly air mass that originates from polar regions and traverses the industrialized or semi-industrialized countries and the Black Sea sets the lower limits for both PM10 and SO2 as 13 and 2.9 mu g/m(3), while southwesterly winds with its Saharan dust load set upper limits for PM10 as an average 300 mu g/m(3) reaching to 800 mu g/m(3) as peak hourly averages. SO2 levels during SW winds were also below 15 mu g/m(3). It has been further shown that the pristine northerly air mass can be used to delineate anthropogenic hot spots that can otherwise impossible to identify due to local perturbations.