Odours are frequently the cause of complaints to regulatory agencies about air quality. The impact of odours can range from detection, to an irritating nuisance or, at high enough concentrations, a health risk.
Managing odours to minimize these effects on the public is a challenging task. Odourous substances are often a mixture of different gases. This makes it very difficult to determine and measure the sources of the odours, and to try to control their emissions.
Odour detection varies greatly with each individual. The sensation of an odour that is “annoying” is subjective. Some find the smell of a bakery pleasant, while others find it nauseating. The issue is complicated by other factors beyond the odour itself — such as the frequency of detection, duration, intensity and offensiveness.