In October 2021, the Environmental Protection Agency (EPA) issued in draft the “Policy Assessment for the Reconsideration of the National Ambient Air Quality Standards for Particulate Matter, External Review Draft.”  In it, the EPA reconsiders the review of the National Ambient Air Quality Standards (NAAQS) for particulate matter completed in December 2020 under President Trump. That review resulted in a decision to retain the particulate matter NAAQS from 2012. Subsequently, in June 2021, the EPA announced it would again review the standards in light of evidence indicating the current particulate matter standards may not be sufficient to protect public health and welfare.

The Clean Air Act requires EPA to set NAAQS for six criteria pollutants deemed to be harmful to public health and the environment: particulate matter: ozone, nitrogen oxides, carbon monoxide, sulfur dioxide, and lead. The EPA is also required to review these standards periodically to determine whether or not to retain or revise the policy to ensure public health and the environment are protected.

EPA is required to set both primary standards (to protect public health) and secondary standards (to protect public welfare). The primary standards must protect public health with an adequate margin of safety, including the health of sensitive groups of people such as children, older adults, and those with heart or lung disease.

Particulate matter describes a mixture of solid and liquid droplets found in the air, including dust, dirt, soot, and smoke, and can be emitted directly from a source or can form as a result of reactions of chemicals emitted from industries or automobiles. Fine particulate matter or PM_2.5 refers to very fine inhalable particles with diameters that are generally 2.5 micrometers and smaller. These smaller particles represent the greatest risk to human health and can be inhaled more deeply into the lungs and even enter the bloodstream.

In the October announcement, EPA indicated it is reconsidering the standards due to current scientific evidence indicating that long- and short-term exposure to fine particulate matter (PM_2.5) can contribute to heart attacks, asthma attacks, and premature deaths. There are also potential health associations between COVID and exposure to particulate matter. In addition, the EPA received petitions and lawsuits requesting the standards be reviewed.

As part of the NAAQS review process, EPA developed a supplement to the 2019 Final Integrated Science Assessment with the most recent studies and research related to the health and welfare effects of particulate matter. This research will be reviewed by the Clean Air Scientific Advisory Committee (CASAC) and a particulate matter review panel of experts, who will provide advice and recommendations regarding the standards.

The EPA expects to issue a proposed rulemaking in summer 2022 and a final rule in spring 2023 after opportunities for public review and comment.

As Chemical Data Management Specialist, Catherine Nies’s responsibilities focus on verifying and utilizing the information in our Foundation system, including Tier II reporting, permit summaries, EPCRA reports, and any other high priority needs of our clients. Additionally, Catherine is involved in tracking EPA, OSHA, CDC, state, and local regulatory updates.