Predicting the impact an air quality - atmospheric dispersion modelling

The incineration of waste - whether it be clinical, chemical or municipal - inevitably results in gaseous (and often particulate) emissions, which are usually vented to atmosphere via a chimney. A stack of adequate height is needed to ensure that the pollutants are sufficiently diluted and dispersed in the atmosphere before the plume reaches ground level, where it can impact on human health, flora and fauna. Atmospheric dispersion models can be used to predict ground level pollutant concentrations, and therefore measures can be taken to optimise chimney design and emission parameters prior to construction and commissioning. This paper reviews the various dispersion models available, their relative merits, and the type of information which can be derived from them. The results of dispersion modelling need to be assessed against recognised air quality standards and guidelines (primarily for the protection of human health) and these are described.