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Release of Draft Document Related to the Review of the National Ambient Air Quality Standards for Carbon Monoxide

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Information about this document as published in the Federal Register.

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Environmental Protection Agency (EPA).


Availability of draft document for public comment.


On or about October 20, 2009, the Office of Air Quality Planning and Standards (OAQPS) of EPA is making available for public comment a draft assessment document: Risk and Exposure Assessment to Support the Review of the Carbon Monoxide (CO) Primary National Ambient Air Quality Standards—First External Review Draft. This draft document describes the quantitative analyses that are being conducted as part of the review of the National Ambient Air Quality Standards (NAAQS) for carbon monoxide (CO).


Comments should be submitted on or before November 19, 2009.


Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2008-0015, by one of the following methods:

  • Follow the online instructions for submitting comments.
  • E-mail: Comments may be sent by electronic mail (e-mail) to, Attention Docket ID No. EPA-HQ-OAR-2008-0015.
  • Fax: Fax your comments to 202-566-9744, Attention Docket ID. No. EPA-HQ-OAR-2008-0015.Start Printed Page 55844
  • Mail: Send your comments to: Air and Radiation Docket and Information Center, Environmental Protection Agency, Mailcode: 2822T, 1200 Pennsylvania Ave., NW., Washington, DC 20460, Attention Docket ID No. EPA-HQ-OAR-2008-0015.
  • Hand Delivery or Courier: Deliver your comments to: EPA Docket Center, 1301 Constitution Ave., NW., Room 3334, Washington, DC. Such deliveries are only accepted during the Docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information.

Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-2008-0015. The EPA's policy is that all comments received will be included in the public docket without change and may be made available online at, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through or e-mail. The Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an e-mail comment directly to EPA without going through, your e-mail address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses.

Docket: All documents in the docket are listed in the index. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. Publicly available docket materials are available either electronically in or in hard copy at the Air Docket in the EPA Docket Center, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. This Docket Facility is open from 8:30 a.m. to 4:30 p.m. Monday through Friday, excluding legal holidays. The Docket telephone number is 202-566-1742; fax 202-566-9744.

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For questions related to the draft document titled, Risk and Exposure Assessment to Support the Review of the Carbon Monoxide (CO) Primary National Ambient Air Quality Standards—First External Review Draft (October 2009), please contact Dr. Ines Pagan, Office of Air Quality Planning and Standards (Mail Code C504-06), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711; e-mail:; telephone: 919-541-5469; fax: 919-541-0237.

General Information

A. What Should I Consider as I Prepare My Comments for EPA?

1. Submitting CBI. Do not submit this information to EPA through or e-mail. Clearly mark the part or all of the information that you claim to be CBI. For CBI information in a disk or CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as CBI and then identify electronically within the disk or CD-ROM the specific information that is claimed as CBI. In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2.

2. Tips for Preparing Your Comments. When submitting comments, remember to:

  • Identify the rulemaking by docket number and other identifying information (subject heading, Federal Register date and page number).
  • Follow directions—The agency may ask you to respond to specific questions or organize comments by referencing a Code of Federal Regulations (CFR) part or section number.
  • Explain why you agree or disagree; suggest alternatives and substitute language for your requested changes.
  • Describe any assumptions and provide any technical information and/or data that you used.
  • If you estimate potential costs or burdens, explain how you arrived at your estimate in sufficient detail to allow for it to be reproduced.
  • Provide specific examples to illustrate your concerns, and suggest alternatives.
  • Make sure to submit your comments by the comment period deadline identified.
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Under section 108(a) of the Clean Air Act (CAA), the Administrator identifies and lists certain pollutants which “cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare.” The EPA then issues air quality criteria for these listed pollutants, which are commonly referred to as “criteria pollutants.” The air quality criteria are to “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of [a] pollutant in the ambient air, in varying quantities.” Under section 109 of the CAA, EPA establishes primary (health-based) and secondary (welfare-based) NAAQS for pollutants for which air quality criteria are issued. Section 109(d) of the CAA requires periodic review and, if appropriate, revision of existing air quality criteria. The revised air quality criteria reflect advances in scientific knowledge on the effects of the pollutant on public health or welfare. The EPA is also required to periodically review and revise the NAAQS, if appropriate, based on the revised criteria.

Presently, EPA is reviewing the air quality criteria and NAAQS for CO. The EPA's overall plan and schedule for this review is presented in the Integrated Review Plan for the National Ambient Air Quality Standards for Carbon Monoxide.[1] A draft of the integrated review plan was released for public review and comment in March 2008 and was the subject of a consultation with the Clean Air Scientific Advisory Committee (CASAC) on April 8, 2008 (73 FR 12998). Comments received from that consultation and from the public were considered in finalizing the plan and in beginning the review of the air quality criteria.

As part of EPA's review of the primary (health-based) CO NAAQS, the Agency is conducting qualitative and quantitative assessments characterizing the health risks associated with exposure to ambient CO. The EPA's plans for conducting these assessments, including the proposed scope and methods of the analyses, were presented in a planning document titled, Carbon Start Printed Page 55845Monoxide National Ambient Air Quality Standards: Scope and Methods Plan for Health Risk and Exposure Assessment (Scope and Methods Plan). This document was released for public comment in April 2009 and was the subject of a consultation with the CASAC on May 13, 2009 (74 FR 15265). Comments received from the CASAC consultation (Brain and Samet, 2009) [2] as well as public comments on the Scope and Methods Plan have been considered in developing the draft assessment document being released at this time.

The draft document announced today conveys the approaches taken to assess exposures to ambient CO and to characterize associated health risks, as well as present the initial key results, observations, and related uncertainties associated with the quantitative analyses performed. This draft document will be available on or about October 20, 2009, through the Agency's Technology Transfer Network (TTN) Web site at​ttn/​naaqs/​standards/​co/​s_​co_​index.html. This document may be accessed in the “Documents from Current Review” section under “Risk and Exposure Assessments.” The EPA is soliciting advice and recommendations from the CASAC by means of a review of the draft document at an upcoming public meeting of the CASAC scheduled in Chapel Hill, NC. Information about this public meeting, including the date and location, has been published as a separate notice in the Federal Register (74 FR 48536) on September 23, 2009. Following the CASAC meeting, EPA will consider comments received from the CASAC and the public in preparing revisions to this assessment document.

The draft document briefly described above does not represent and should not be construed to represent any final EPA policy, viewpoint, or determination. The EPA will consider any public comments submitted in response to this notice when revising the documents.

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Dated: October 15, 2009.

Jennifer Noonan Edmonds,

Acting Director, Office of Air Quality Planning and Standards.

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[FR Doc. E9-26093 Filed 10-28-09; 8:45 am]