Integrated Science Assessment for Particulate Matter (External Review Draft)

The Environmental Protection Agency (EPA) is announcing a public comment period for the draft document titled, ``Integrated Science Assessment for Particulate Matter (External Review Draft)'' (EPA/600/R-18/179). The draft document was prepared by the National Center for Environmental Assessment (NCEA) within EPA's Office of Research and Development (ORD) as part of the review of the primary (health-based) and secondary (welfare-based) National Ambient Air Quality Standards (NAAQS) for particulate matter. The welfare-based effects evaluated consist of non-ecological effects, specifically visibility impairment, climate effects, and effects on materials. The Integrated Science Assessment (ISA), in conjunction with additional technical and policy assessments, provides the scientific basis for EPA's decisions on the adequacy of the current NAAQS and the appropriateness of possible alternative standards. EPA is currently developing a separate ISA to support the secondary NAAQS review for ecological effects for oxides of nitrogen, oxides of sulfur, and particulate matter. EPA is releasing this draft document to seek review by the Clean Air Scientific Advisory Committee (CASAC) and the public. In addition, the date and location of a public meeting for CASAC review of this document will be specified in a separate Federal Register notice. This draft document is not final and it does not represent, and should not be construed to represent, any final Agency policy or views. When revising the document, EPA will consider any public comments submitted during the public comment period specified in this notice.