Abstract
Measurements of gaseous air pollutants and water soluble ions (SO42-, NO3, Cl-, NH4+) were performed at four sites in the urban area of Mansoura city and surroundings and at another background site in a rural area near the city. The results showed that concentrations of gaseous air pollutants undergo seasonal variations characterized by winter maximum levels for SO2 (41.95 mu g/m(3)), and H2S (21.46 mu g/m(3)), autumn maximum levels for NO2 (72.21 mu g/m(3)) and summer maximum levels for total photochemical oxidants (332.33 mg/m(3)). Higher concentrations of SO42- followed by NH4+, Cl- and NO3-, respectively were found in the total water soluble ions (TWSI). These major ions also showed seasonal variations with maximum concentration in summer/autumn for SO42-, NO3- and NH4+ and spring for Cl-. A statistical analysis of long term measurement data for the measured pollutants indicated strong correlations. It can be concluded that the industrial and residential activities beside the traffic emission are the major sources of air pollutants in the atmosphere of this investigated area. Also the existence of these pollutants in the presence of sun light causes the formation of secondary pollutants, like ozone.