Modelling Air Quality

Because we cant measure air pollution in every place where it occurs, models are used to simulate the dispersion of air pollutants away from emission sources, and to estimate ground level pollution concentrations. Dispersion models range from simple paper based models, providing information in the form of graphs and tables, to advanced computer programmes.

The more advanced models also simulate the development of secondary pollutants such as ozone by examining the chemical reactions occurring during the movement of primary pollutants through the atmosphere.

Air dispersion models are useful for ensuring that emissions of air pollutants do not result in a failure to meet National Air Quality Standards. They also help to predict the effect of a new emissions source, and can be used to assess the impacts of various emission control strategies.

To a large extent, the accuracy of the model depends upon the quality of the data being used. Even with very precise information, there will always be a degree of uncertainty associated with the model estimates, due to the variability of weather patterns and pollution emission conditions.