Particulate Matter Air Quality Standards: Background and Current Developments

Following a brief summary of recent developments regarding the implementation and re-evaluation of the 1997 standards, this report provides a broad overview of the standard-setting process, followed by a description of revisions to earlier standards, legal challenges to the 1997 standard, and particulate matter health effects research. EPA’s ongoing progress in reviewing the 1997 standard is then summarized. Other activities that potentially impact the implementation and review of the particulate matter standards, such as other air quality regulations and proposed legislation, are also discussed in this report