The section begins with an overview of air pollution, its impacts, sources and national trends. Commonly-used air pollution concepts and terminology are introduced. It concludes with a discussion of air quality issues of greatest concern in Indian country. Used in combination with knowledge of local air quality conditions and sources of pollution, this information can be used to assist personnel in making air quality planning decisions on Indian reservations. Air Quality Overview Understanding the nature of an area's air pollution problem requires a basic knowledge of pollution formation principles.
Air pollution is caused by the build-up of harmful gases and particles in the air.
Many factors determine whether a reservation has an air pollution problem, and if so, what the nature of the pollution problem is. The relationship between each of these factors is discussed briefly here. Factors which influence the amount of pollution emitted into the air include the number of pollution sources in an area, their levels of activity, and their emissions rate. The number of sources refers to the number of cars, factories and other potential pollution sources in the area of interest. The level of activity is how much each of the identified sources is used.