ABSTRACT
In the introduction to this part of the book, we mentioned that air quality degradation in the Southwest comes from two main sources. One consists of a relatively few but very large industrial emitters. The other is a multitude of small emission sources—automotive vehicles. Unless effective action is taken, the latter as well as the former will become worse as resource development, general population growth, and economic development proceed. We now turn to a discussion of automotive emissions. In the introduction we also outlined the early history of federal legislation pertaining to mobile sources of airborne residuals. Before turning to a discussion of the specific problem in the Southwest, we fill in the more recent history of federal regulatory efforts for automotive emissions.
