Dictionary of Allergies .. Airshed

Airshed

An airshed is the geographic area responsible for emitting a significant percentage of the air pollution reaching a body of water. Since different pollutants behave differently in the atmosphere, the airshed of a given body of water may vary depending on the pollutant of interest. While watersheds are actual physical features of the landscape, airsheds are determined using mathematical models of atmospheric deposition. The first documented use of the term airshed was in Robert Avrill's Man and Environment [1] where he talked about the need for local, regional and national air quality management. It's analogous to the more widely used concept of the watershed. The term is not much used in the UK, but is the basis of regulatory approach in North America, Australia and New Zealand.

References

Man and Environment 4th Edition Penguin 1976.