Parameters for the assessment of odour impacts on communities

Odorous emissions are the cause of most air pollution complaints that are made by the public to regulatory agencies. Methods need to be developed to objectively access the impact of odours so that odour-producing facilities have a pro-active means of reducing their impact on surrounding communities. These methods must consider the sub- and supra-threshold effects of odour over the range of concentrations that can be experienced as the odour disperses over a community. In addition, the influence of local meteorological and terrain conditions can be accommodated through conventional dispersion models. However, metrics of odour impact need to be developed which take into account the concentration and frequency of odours at receptors, as well as the population density at those receptors. This paper proposes and demonstrates the use of six impact parameters that may be used as metrics of the impact of a stationary odour source on a community. These odour impact parameters are maximum concentration, maximum probability of response, footprint area, concentration-weighted footprint area, probability-weighted footprint area and population impact. The utility of these parameters were demonstrated by evaluating them to quantify the impact of an industrial facility that produces an odorous chemical.