US EPA

This draft Supplement to the 2019 Integrated Science Assessment (ISA) for Particulate Matter represents the Agency’s targeted evaluation of the scientific literature on potential health and welfare effects associated with particulate matter (PM) published since the literature cutoff date of the 2019 PM ISA. This Supplement in combination with the 2019 PM ISA represents the scientific basis of the reconsideration of the primary (health-based) and secondary (welfare-based) National Ambient Air Quality Standards (NAAQS) for PM that was finalized in 2020.

In June 2021, the U.S. EPA announced it will reconsider the December 2020 decision to retain the particulate matter (PM) National Ambient Air Quality Standards (NAAQS). As part of the reconsideration process, the U.S. EPA indicated that it would develop a supplement to the 2019 Integrated Science Assessment for PM (PM ISA) to thoroughly evaluate the most up-to-date science that became available after the literature cutoff date of the 2019 PM ISA that could either further inform the adequacy of the current PM NAAQS or address key scientific topics that have evolved since the 2020 PM NAAQS review was completed.

The Clean Air Act requires EPA to periodically review the science for six major air pollutants, including particulate matter (PM). EPA's Center for Public Health and Environmental Assessment (CPHEA) develops Integrated Science Assessments (ISAs) that summarize the science related to the health and welfare effects of these pollutants. ISAs provide a comprehensive review of the policy-relevant scientific literature published since the last National Ambient Air Quality Standards (NAAQS) review and are a critical part of the scientific basis for updating the NAAQS.

This draft Supplement builds on the 2019 PM ISA and represents EPA’s targeted evaluation of the latest scientific literature on the potential health and welfare effects associated with PM. The draft Supplement and 2019 PM ISA collectively forms the scientific basis of the reconsideration of the PM NAAQS.

This draft Supplement will be reviewed by a panel of the Clean Air Scientific Advisory Committee (CASAC) at a public meeting scheduled in November/December 2021. The public meeting for the panel to peer review the documents will be held from November 17-19, 2021 and again from December 1-2, 2021. See the SAB FR Sep 22, 2021 for additional details.

U.S. EPA. Supplement to the 2019 Integrated Science Assessment for Particulate Matter (External Review Draft, 2021). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-21/198, 2021.

For information on the public comment period, contact the ORD Docket at the EPA Headquarters Docket Center; phone: 202-566-1752; fax: 202-566-9744; or email: Docket_ORD@epa.gov.

For technical information, contact Mr. Jason Sacks, CPHEA; phone: 919-541-9729; fax: 919-541-1818; or email: sacks.jason@epa.gov.