An official website of the United States government
Here’s how you know
Official websites use .gov A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
On June 10, 2021, the EPA Administrator announced his decision to reconsider the December 2020 decision to retain the particulate matter (PM) National Ambient Air Quality Standards (NAAQS). These standards were last revised in 2012. EPA is reconsidering the 2020 decision because available scientific evidence and technical information suggests that the current standards may not be adequate to protect public health and welfare. EPA has requested CASAC review of updates to the science assessment that will supplement the existing record.
On this page:
See EPA’s PDF page to learn more about PDF files.
Top of Page