Integrated Science Assessments (ISAs)
[NOTICE] EPA announced the availability of the Integrated Science Assessment for Oxides of Nitrogen, Oxides of Sulfur, and Particulate Matter – Ecological Criteria (Final Report) in an October 19, 2020 Federal Register Notice.
EPA has set National Ambient Air Quality Standards (NAAQS) for six principal criteria air pollutants, which include nitrogen oxides, sulfur oxides, particulate matter, carbon monoxide, ozone and lead. Numerous sources emit these "criteria pollutants", which are considered harmful to public health and the environment.
Since 2008, EPA’s Integrated Science Assessments (ISAs) have formed the scientific foundation for the review of the NAAQS standards by providing the primary (human health-based) and secondary (welfare-based, e.g. ecology, visibility, materials) science assessments: