Suspended particulates and sulphur compounds in Cairo urban atmosphere

ABSTRACT

This work presents the outcome of a research project conducted to investigate suspended particulates and sulphur compounds in Cairo atmosphere. It has been found that Cairo urban air is heavily polluted with suspended particulates reaching more than the 24 h air quality standard during 100% of measured days with annual mean concentration of approximately 9 times USA air quality standard recorded in Cairo central district. This TSP concentration was found to be associated with sulphur dioxide concentrations of about double the WHO annual recommended limit of 53 micro g/m[3]. Moreover the rate of total sulphation reached a maximum value of 39.8 mg/100 cm[2] 30 d during Sept 1989. A good correlation of more than 0.85 was found between total sulphation and sulphur dioxide in Cairo atmosphere with a straight line relationship of SO2 [micro g/m[3]] = 2.96 [T. sulphation] + 0.39. Furthermore, a good correlation of more than 0.6 was found between the concentrations of paniculate sulphates and ammonium. This confirms that atmospheric reactions are a principal source of paniculate sulphates in Cairo atmosphere. Several other conclusions and recommendations are included