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ENVIRONMENTAL PROTECTION AGENCY

[FRL-8271-9; Docket ID No. EPA-HQ-ORD-2006-0868]

Metabolically-Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates

AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of public comment period.
SUMMARY: In 1997, NCEA published the Exposure Factors Handbook. This comprehensive document provides summaries of available statistical data on various factors that can impact an individual's exposure to environmental contaminants. NCEA maintains the Exposure Factors Handbook and periodically updates the document using current literature and other reliable data made available through research. Many program offices within EPA rely on the data from this handbook to conduct their exposure and risk assessments.

One important determinant of a person's exposure to contaminants in air is the ventilation rate, or the volume of air that is inhaled by an individual in a specified time period. Ventilation rates, also known as breathing or inhalation rates, are given in Chapter 5 of the Exposure Factors Handbook. Calculations of the currently recommended ventilation rates were limited by their dependence on a "ventilatory equivalent," which relied on a person's fitness level. This draft report, "Metabolically-Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates," presents a revised approach that calculates ventilation rates directly from an individual's oxygen consumption rate, and applies this method to data provided from more recent sources, such as the 1999-2002 National Health and Nutrition Examination Survey (NHANES) and EPA's Consolidated Human Activity Database (CHAD). In the next edition of the Exposure Factors Handbook, NCEA would like to update the ventilation rate values using this revised approach and the more recently released data.

EPA is releasing the draft, "Metabolically-Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates," solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. This document has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency policy or determination. EPA will consider any public comments submitted in accordance with this notice when revising the document.

DATES: The 30-day public comment period begins January 24, 2007, and ends February 23, 2007. Technical comments should be in writing and must be received by EPA by February 23, 2007. In a subsequentFederal Registernotice EPA will announce the details of an external peer review meeting that will be conducted via teleconference.
ADDRESSES: The draft, "Metabolically-Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates," is available primarily via the Internet on the National Center for Environmental Assessment's home page under the Recent Additions and the Data and Publications menus athttp://www.epa.gov/ncea.A limited number of paper copies are available from the Technical Information Staff, NCEA-W; telephone: 202-564-3261; facsimile: 202-565-0050. If you are requesting a paper copy, please provide your name, your mailing address, and the document title, "Metabolically-Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates" (EPA/600/R-06/129A).

Comments may be submitted electronically viawww.regulations.gov,by mail, by facsimile, or by hand delivery/courier. Please follow the detailed instructions provided in theSUPPLEMENTARY INFORMATIONsection of this notice.

FOR FURTHER INFORMATION CONTACT: For information on the public comment period, contact the Office of Environmental Information Docket; telephone: 202-566-1752; facsimile: 202-566-1753; or e-mail:ORD.Docket@epa.gov.

For technical information, contact Laurie Schuda, NCEA; telephone: 202-564-3206; facsimile: 202-564-2018; or e-mail:schuda.laurie@epa.gov.

SUPPLEMENTARY INFORMATION: How To Submit Technical Comments to the Docket at www.regulations.gov

Submit your comments, identified by Docket ID No. EPA-HQ-ORD 2006-0868 by one of the following methods:

www.regulations.gov:Follow the on-line instructions for submitting comments.

E-mail: ORD.Docket@epa.gov.

Fax:202-566-1753.

Mail:Office of Environmental Information (OEI) Docket (Mail Code: 2822T), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460. The phone number is 202-566-1752.

Hand Delivery:The OEI Docket is located in the EPA Headquarters Docket Center, Room 3334, EPA West Building, 1301 Constitution Ave., NW., Washington, DC. The EPA Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is 202-566-1744. Such deliveries are only accepted during the docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information.

If you provide comments by mail or hand delivery, please submit one unbound original with pages numbered consecutively, and three copies of the comments. For attachments, provide anindex, number pages consecutively with the comments, and submit an unbound original and three copies.

Instructions:Direct your comments to Docket ID No. EPA-HQ-ORD-2006-0868. Please ensure that your comments are submitted within the specified comment period. Comments received after the closing date will be marked “late,” and may only be considered if time permits. It is EPA's policy to include all comments it receives in the public docket without change and to make the comments available online atwww.regulations.gov,including any personal information provided, unless a 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 throughwww.regulations.govor e-mail. Thewww.regulations.govWeb 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 throughwww.regulations.gov,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. For additional information about EPA's public docket visit the EPA Docket Center homepage athttp://www.epa.gov/epahome/dockets.htm.

Docket:Documents in the docket are listed in thewww.regulations.govindex. 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 materials, such as copyrighted material, are publicly available only in hard copy. Publicly available docket materials are available either electronically inwww.regulations.govor in hard copy at the OEI Docket in the EPA Headquarters Docket Center.

Dated: January 12, 2007. George Alapas, Acting Director, National Center for Environmental Assessment.