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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 policy assessment that will supplement the existing record.
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See EPA’s PDF page to learn more about PDF files.
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