The emissions of toxic air pollutants from three power plants and one oil refinery were measured for a period of six months and dispersion of pollutants were calculated by using Air Dispersion Modelling Software (ADMS–4). The plume concentration of carbon monoxide, oxides of nitrogen, sulphur dioxide and particulate matter were calculated over long distances to estimate the incremental contribution of these fossil fuel combustion facilities to ambient air. Overall in four plants, the emissions of sulphur dioxide were most critical and 50% of the total exposure was predicted within 20 km distance and the rest of the exposure was observed up to 70 km distances in radii of each plant. Although the annual average concentration increments from a limited number of sources studied were relatively small, but the long–range transport of pollutants created potentially significant health and environmental impacts.
Keywords: air pollution, pollutant dipersion, dispersion modelling, ADMS–4, emissions, pollutants, NOx, SO2, sulphur dioxide, particulate matter, fossil fuels, fuel combustion, plume concentration, carbon monoxide, nitrogen oxides, environmental impact, health impact