Peer Input Workshop to Review Initial Draft Materials for the Oxides of Nitrogen Integrated Science Assessment - Health Session Part Two

The Environmental Protection Agency (EPA) is preparing an Integrated Science Assessment (ISA) as part of the review of the primary (health-based) National Ambient Air Quality Standards (NAAQS) for oxides of nitrogen. As part of this review, EPA is announcing a series of public workshops to evaluate preliminary draft materials that will inform the development of the ISA for oxides of nitrogen. This presentation is part of the workshop series and contains information surrounding the Health chapters of the draft ISA. Preliminary materials are not being released externally but will be provided to the panelists to guide discussions that will inform the development of the draft ISA for oxides of nitrogen.

Impact/Purpose

The U.S. Environmental Protection Agency (EPA) is conducting a review of the health-based air quality criteria and the primary (health-based) National Ambient Air Quality Standards (NAAQS) for oxides of nitrogen. Ambient concentrations of oxides of nitrogen are influenced by both direct nitrogen dioxide (NO2) emissions and by emissions of nitric oxides (NO), with the subsequent conversation of NO to NO2 primarily through reaction with ozone (O3).  Consistent with the reviews completed in 2010 and 2018, this review focuses on health effects associated with gaseous oxides of nitrogen and the protection afforded by the primary NO2 standards. The gaseous oxides of nitrogen include NO2 and NO, as well as their gaseous reaction products. Total oxides of nitrogen include these gaseous species as well as particulate species (e.g., nitrates). Health effects and non-ecological welfare effects associated with the particulate species are addressed in the review of the NAAQS for particulate matter (PM). The EPA is separately reviewing the ecological welfare effects associated with and the secondary standards for oxides of nitrogen, oxides of sulfur, and PM. As part of this review, EPA is announcing a series of public workshops to evaluate preliminary draft materials that will inform the development of the ISA for oxides of nitrogen. This presentation is for part of the workshop. Preliminary materials are not being released externally but will be provided to the panelists to guide discussions that will inform the development of the draft ISA for oxides of nitrogen.

Citation

Lehmann, D., C. Holesovsky, A. Krajewski, AND A. Wilkie. Peer Input Workshop to Review Initial Draft Materials for the Oxides of Nitrogen Integrated Science Assessment - Health Session Part Two. 2024 Workshops to Obtain Input on Initial Draft Materials for the Integrated Science Assessment (ISA) for Oxides of Nitrogen – Health Criteria Part Two, RTP, NC, October 31, 2024.

• NOX WORKSHOP PRESENTATION_HUMAN HEALTH #2_FINAL_2024OCT28_508ED (003).PPTX