Document ID: EPA-HQ-OAR-2005-0172-0204
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-06-20T04:00Z

Lydia Wegman/RTP/USEPA/US 

06/19/2007 03:35 PM

	

To

afarrell@ceq.eop.gov

cc

richmond.harvey@epa.gov

Subject

Fw: language clarifying exposure/risk are not predictions 

Would this language meet your concern on the risk modeling issue?  We'd
like to use it instead of the language you sent me.  Let me know what
you think and call me if we should discuss it. 

----- Forwarded by Lydia Wegman/RTP/USEPA/US on 06/19/2007 03:33 PM
-----

Harvey Richmond/RTP/USEPA/US

06/19/2007 01:39 PM

	

To

Lydia Wegman/RTP/USEPA/US@EPA

cc

martin.karen@epa.gov

Subject

Re: language clarifying exposure/risk are not predictions 

Lydia,

Here is language that John Langstaff and I have developed to address
Amy's concern.  This would go in the introductory section to exposure
and risk (II.B.).

Harvey

In modeling exposures and health risks associated with just meeting the
current and alternative O3 standards, EPA has simulated air quality to
represent conditions just meeting these standards based on O3 air
quality patterns in several recent years and on how the shape of the O3
air quality distribution have changed over time based on historical
trends in monitored O3 air quality data.  As described in the Staff
Paper (section 4.5.8) and discussed below , recent O3 air quality
distributions have been statistically adjusted to simulate just meeting
the current and selected alternative standards.  These simulations do
not reflect any consideration of specific control programs or strategies
designed to achieve the reductions in emissions required to meet the
specified standards.  Further, these simulations do not represent
predictions of when, whether, or how areas might meet the specified
standards.  

    Harvey M. Richmond

    Ambient Standards Group

    Health and Environmental Impacts Division

    U.S. EPA

    C504-06

    RTP, NC  27711

    (office) 919-541-5271

    (fax) 919-541-0237

    (email)  richmond.harvey@epa.gov