Air quality data (ground level ozone (O3), NO, NOx, SO2, CO, H2S and NH3) of two Kuwaiti urban areas adjacent to petroleum processing facilities, Fahaheel and Al-Riqa, were analyzed and compared to evaluate: (1) the exceedances of the Kuwait Environment Public Authority (KUEPA) air quality limits, (2) primary air pollution sources and their contribution to the ambient load, (3) diurnal patterns...