1. Status of the PM NAAQS Review

2. Review Process for NAAQS
EPA Staff Paper – interprets scientific data and identifies factors to consider in setting standards including staff recommendations for standards
Scientific studies on health and environmental effects
EPA Criteria Document – extensive assessment of scientific studies
Scientific peer review of published studies
Reviews by CASAC and the public
Reviews by CASAC and the public
Final decision on standards
Public hearings and comments on proposals
Proposed decision on standards

3. Timeline for PM NAAQS Review
Under a consent agreement for the PM and O3 Reviews
PM Criteria Document
final in October 2004 (done)
FR notices signed
proposal - December 20, 2005
final rule - September 27, 2006
PM Staff Paper milestones
August, release of first draft Staff Paper (done)
November, CASAC meeting on first draft Staff Paper (done)
January 31, release of second draft Staff Paper (done)
April, CASAC meeting to review second draft Staff Paper
June 30, final Staff Paper
Web address for Staff Papers:

4. Second Draft PM Staff Paper . . . Staff Recommendations on Primary Standards
Consideration should be given to revising the current PM2.5 primary standards to provide increased public health protection from the effects of both long- and short-term exposures to fine particles
Based on newly available epidemiologic, toxicologic, dosimetric, and exposure-related evidence
Taking into account evidence of mortality and morbidity effects in areas where the current standards were met, together with judgments as to the public health significance of the estimated incidence of effects upon just attaining the current standards
Should revise the current primary PM10 standards in part by replacing the PM10 indicator with an indicator of thoracic coarse particles that does not include fine particles (e.g., PM10-2.5)

5. Second Draft PM Staff Paper
Second Draft PM Staff Paper Staff Recommendations on Primary Standards (cont.)
PM2.5 primary standards should continue to be based on both annual and 24-hour averaging times
Consideration should be given to an annual PM2.5 standard at the current level of 15 µg/m3 together with a revised 24-hour PM2.5 standard in the range of 35 to 25 µg/m3 OR
Consideration should also be given to a revised annual PM2.5 standard, within the range of 14 to 12 µg/m3, together with a revised 24-hour PM2.5 standard in the range of 40 to 35 µg/m3, to provide supplemental protection against episodic localized or seasonal peaks

6. Second Draft PM Staff Paper
Second Draft PM Staff Paper Staff Recommendations on Primary Standards (cont.)
Consideration should be given to setting a 24-hour PM standard about as protective as the current daily PM10 standard, with a level in the range of approximately 65 to 75 µg/m3, 98th percentile, or approximately 75 to 85 µg/m3, 99th percentile.
Also some support for consideration of a PM standard down to approximately 30 µg/m3, 98th percentile, or 35 µg/m3, 99th percentile, recognizing that a standard set at such a relatively low level would place a great deal of weight on very limited and uncertain epidemiologic associations

7. Second Draft PM Staff Paper
Second Draft PM Staff Paper Staff Recommendations on Secondary Standards
Consideration should be given to revising the current secondary PM2.5 standards to provide increased and more targeted protection primarily in urban areas from visibility impairment related to fine particles
Consideration should be given to a 4- to 8-hour PM2.5 standard in the range of 30 to 20 µg/m3 to protect visual air quality primarily in urban areas (generally resulting in a visual range of approximately 25 to 35 km), as well as in surrounding non-urban areas
Consideration should be given to using a percentile-based form for such a standard, focusing on a range at or somewhat above the 90th percentile of the annual distribution of daily short-term PM2.5 concentrations, averaged over 3 years

8. Second Draft PM Staff Paper
Second Draft PM Staff Paper Staff Recommendations on Secondary Standards (cont.)
Consideration should be given to retaining secondary standards for fine and coarse-fraction particles that retain the level of protection afforded by the current PM2.5 and PM10 standards so as to continue control of ambient particles, especially long-term deposition of particles such as nitrates and sulfates, that contribute to adverse impacts on vegetation and ecosystems and on materials damage and soiling