Integrated Science Assessment (ISA) for Sulfur Oxides – Health Criteria (Final Report)

This concise synthesis of the most policy-relevant science forms the scientific foundation for the review of the primary (health-based) NAAQS for SO_x . The primary NAAQS for SO_x , with SO₂ serving as the indicator, is set at 0.14 parts per million (ppm), averaged over a 24 h period, not to be exceeded more than once per year, and 0.030 ppm annual arithmetic mean. The ISA accurately reflects “the latest scientific knowledge useful in indicating the kind and extent of identifiable effects on public health which may be expected from the presence of [a] pollutant in ambient air” Clean Air Act, Section 108, 1: (2003) . Key information and judgments formerly contained in the Air Quality Criteria Document (AQCD) for SO_x are incorporated in this assessment. Additional details of the pertinent scientific literature published since the last review, as well as selected older studies of particular interest, are included in a series of annexes. This ISA thus serves to update and revise the information available at the time of the previous review of the NAAQS for SO_x in 1996.

This is the final report.