Release of Draft Documents Related to the Review of the National Ambient Air Quality Standards for Particulate Matter

摘要

On or about September 4, 2009, the Office of Air Quality Planning and Standards (OAQPS) of EPA is making available for public comment two draft assessment documents: Risk Assessment to Support the Review of the PM Primary National Ambient Air Quality Standards-- External Review Draft and Particulate Matter Urban-Focused Visibility Assessment--External Review Draft. These draft documents describe the quantitative analyses that are being conducted as part of the review of the National Ambient Air Quality Standards (NAAQS) for particulate matter (PM).