Today, EPA adopts revisions to the uniform air quality index used by States for daily air quality reporting to the general public in accordance with section 319 of the Clean Air Act (Act). These changes include the addition of the following elements: a new category described as ``unhealthy for sensitive groups;'' two new requirements, first, to report a pollutant-specific sensitive group statement when the index is above 100, and second, to use specific colors if the index is reported in a color format; new breakpoints for the ozone (0<INF>3</INF>) sub-index in terms of 8-hour average 0<INF>3</INF> concentrations; a new sub-index for fine particulate matter (PM<INF>2.5</INF>); and conforming changes to the sub-indices for coarse particulate matter (PM<INF>10</INF>), carbon monoxide (CO), and sulfur dioxide (SO<INF>2</INF>). In addition, EPA is changing the name of the index from the Pollutant Standards Index (PSI) to the Air Quality Index (AQI). This document discusses the development of related informational materials on pollutant-specific health effects and sensitive groups and on precautionary actions that can be taken by individuals to reduce exposures of concern. This document also discusses the interrelationship between the uniform air quality index and other programs that provide air quality information and related health information to the general public, including State and local real-time air quality data mapping and community action programs.