In recent years, the term "airshed" has been used to describe those areas where significant portions of emissions result in deposition of the various air pollutants to a region Many types of air pollution are carried by the wind from state to state, and are harmful to people and the environment, even in rural areas
The volume of the atmosphere that must be considered when taking account of the effects of certain types of emissions on human health and the environment The airshed will vary depending on the type of contaminant, weather and geography (especially the built environment), and the actual effect being assessed