7.0 Intro

• set national ambient air quality standards (NAAQS) for six “criteria” pollutants;
• establish national emissions standards for 189 listed hazardous air pollutants (NESHAP);
• establish new source performance standards (NSPS), imposing technology-based requirements on new or modified major sources of pollutants;
• establish emissions standards for mobile sources;
• impose requirements to address specific air pollution problems, such as acid rain and depletion of stratospheric ozone;
• establish nonattainment areas for regions that have failed to meet the NAAQS standards for one or more of the criteria pollutants; and
• require each State to submit a plan for the implementing and enforcing national standards, thus referred to as State Implementation Plans (SIP).  Also required within each SIP are measures to ensure against significant deterioration of air quality in areas that meet NAAQS standards.

In the case of NAAQS, OAQPS sets limits on ambient concentrations of six “criteria” pollutants, allowing the States to determine how best to achieve these standards.  For NESHAPs, NSPS, and emissions standards for mobile sources, OAQPS places limits on the quantity of releases of pollutants into the atmosphere.  Although the specific focus of these rulemakings may differ, the ultimate objective is the same.  As a result, the benefits of all OAQPS regulations can be described as a function of reductions in human health and environmental impacts caused by exposure of humans and the environment to ambient concentrations of air pollutants.  The purpose of this section is to describe a framework for estimating these benefits.