Comparative Assessment of Ambient Air Quality in Two Urban Areas Adjacent to Petroleum Downstream/upstream Facilities in Kuwait

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 of air pollutants and (4) the “weekend effect” on O3 levels. High O3 levels, above the threshold limit for human health, were observed in both urban areas. CO, NOx and NO levels in Fahaheel were higher than in Al-Riqa. Combustion sources (which exist close to Fahaheel) drive both NOx and NO diurnal patterns in both areas. Emissions from downstream facilities and the activity of Fahaheel highway affect the CO levels in the areas. Concentration roses were plotted for annual durations to examine the primary dominant sources of air pollution in both study areas. By establishing a Chemical Mass Balance (CMB) model around the two receptor points in both areas, it was revealed that the downstream facilities sector was the main contributor of air pollutants in Fahaheel. CMB model gave a 70% average contribution of the sector to the Fahaheel receptor point. However, 70% of the total contribution of the studied sources in Al-Riqa urban area was from the traffic and line sources side. The examination of the rate of O3 accumulation, during the high O3 period in Kuwait (April-October), revealed the occurrence of two phases, a fast and a slow one, with different durations in each urban area. Regression equations were used to study the midweek effect of O3 levels. This study supports the hypothesis that O3 weekend variation is due to an NOx emission difference between weekends and weekdays and VOCs sensitivity.