September 16, 2009

MEMORANDUM

SUBJECT: CASAC Discussion of Policy Assessment for the Review of the Particulate Matter National Ambient Air Quality Standards: Preliminary Draft

FROM: Lydia N. Wegman, Director /s/ Health and Environmental Impacts Division (C504-02) Office of Air Quality Planning and Standards United States Environmental Protection Agency

TO: Holly Stallworth Designated Federal Officer Clean Air Scientific Advisory Committee EPA Science Advisory Board Staff Office

Attached is a very preliminary draft document, Policy Assessment for the Review of the

Particulate Matter National Ambient Ai r Quality Standards: Preliminary Draft (Policy Assessment). This document will be the focus of a presentation for and discussion with the Clean Air Scientific Advisory Committee (C ASAC) PM NAAQS Review Panel (the CASAC PM Panel) at a public meeting to be held in Chapel Hill, NC on October 5–6, 2009. This preliminary draft Policy Assessment has been prepared by the Environmental Protection Agency’s (EPA) Office of Air Quality Planning a nd Standards (OAQPS) staff as part of EPA’s ongoing review of the primary (health-based) and secondary (welfare-based) national ambient air quality standards (NAAQS) for particulate matter (PM). I am requesting that you forward this preliminary draft document to th e CASAC PM Panel to prepare fo r our discussion at the October meeting.

Preparation of a Policy Assessment by OAQPS staff reflects Administrator Jackson’s decision to modify the NAAQS review process by reinstating the use of a policy assessment document in lieu of issuing a policy assessment in the form of an advance notice of proposed rulemaking (see http://www.epa.gov/ttn/naaqs/review.html ). We are releasing a very preliminary draft Policy Assessment prior to the upcoming CASAC meeting for informational purposes and to facilitate discus sion with the CASAC PM Panel on th e overall structure, areas of focus, and level of detail to be included in an external review draft Po licy Assessment, which we plan to release for CASAC review a nd public comment later this year.

This preliminary draft document, which is cl early a work in progress, draws from the information and conclusions presented in the Integrated Science Assessment for Particulate Matter: Second External Review Draft (ISA, July 2009) prepared by EPA’s National Center forEnvironm ental Assessment, Research Triangle Pa rk, NC (NCEA-RTP) and two draft assessment documents prepared by OAQPS: (1) Risk Assessment to Support the Review of the PM Primary National Ambient Air Quality Standa rds -- External Review Draft (September 2009) and (2)

Particulate Matter Urban-Focused Visibili ty Assessment – External Review Draft (September 2009). These draft documents will be the subject of review by the CASAC PM Panel at the October meeting

.

Following an introductory chapter, this pr eliminary draft Policy Assessment includes early draft chapters addressing the following: a ch aracterization of ambien t PM (Chapter 2), an overview of the policy-relevant health effects evidence (Chapter 3), and an overview of the policy-relevant eviden ce of PM-related welfare effects and the assessment of PM-related visibility impairment (Chapter 6). Chapter 4, wh ich will present an overv iew of the health risk assessment, is previewed by way of an annotated outline. Chapters 5 and 7, which will present staff conclusions on a range of policy options for the Administrator to consider concerning whether, and if so how, to revise the primar y and secondary PM NAAQS, are previewed only by way of the organization shown in the draft table of contents. These two chapters will discuss both evidence- and risk-based approaches to info rming consideration of the basic elements of each of the PM NAAQS: indicator, averaging time, form, and level.

As noted above, this preliminary draft Polic y Assessment is a work in progress. For example, we are still working to identify and potentially adapt figures from the ISA to sharpen our focus and discussion of the health effects evidence presented in Chapter 3. Additionally, we are continuing our efforts to obtain relevant air quality data from epidemio logic study authors to aid in our evidence-based approach for evaluating the current and potential alternative primary

standards. We are also contin uing to consider how to focus our presentation of the scientific evidence and quantitative analyses in a manner that will most directly help to address the key policy-relevant questions that frame this review . Staff will consider CASAC review and public

comments on the second draft ISA and the two dr aft assessment documents, as well as CASAC discussion of this preliminary draft Policy Asse ssment, in subsequently preparing a complete external review draft Policy Assessment.

We look forward to discussing the prelimin ary draft Policy Assessment with the CASAC PM Panel at our upcoming meeting. Should you ha ve any questions regarding the preliminary draft Policy Assessment or the PM NAAQS review in general, please contact Dr. Karen Martin (919-541-5274; email martin.karen@epa.gov ) or Ms. Beth Hassett-S ipple (919-541-4605; email hassett-sipple.beth@epa.gov ).

Attachments

cc: Vanessa Vu, SAB, OA Karen Martin, OAQPS/HEID Neal Fann, OAQPS/HEID Beth Hassett-Sipple, OAQPS/HEID Bryan Hubbell, OAQPS/HEID Meredith Lassiter, OAQPS/HEID Phil Lorang, OAQPS/AQAD

23 Zach Pekar, OAQPS/HEID Marc Pitchford, OAQPS/HEID Pradeep Rajan, OAQPS/HEID Harvey Richmond, OAQPS/HEID Mary Ross, ORD/NCEA-RTP Vicki Sandiford, OAQPS/HEID Lindsay Stanek, ORD/NCEA-RTP Susan Stone, OAQPS/HEID John Vandenberg, ORD/NCEA-RTP