EcoZone Blog: Secondary NAAQS for NOx SOx

On or about September 13, 2010, the Office of Air Quality Planning and Standards (OAQPS) of EPA is making available a draft report, Policy Assessment for the Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur: Second External Review Draft. The EPA is currently conducting a joint review of the existing secondary (welfare-based) NAAQS for oxides of nitrogen (NOX) and oxides of sulfur (SOx). Because NOx, SOx, and their associated transformation products are linked from an atmospheric chemistry perspective as well as from an environmental effects perspective, and because of the National Research Council's 2004 recommendations to consider multiple pollutants in forming the scientific basis for the NAAQS, EPA has decided to jointly assess the science, risks, and policies relevant to protecting the public welfare associated with NOX and SOX. This is the first time since NAAQS were established in 1971 that a joint review