Re: interesting EPA Workshop on Exposure-Duration

["Michael Eckstein" <me1065@worldnet.att.net>]

Tony,
Eastern Research Group, Lexington, Mass. did provide logistical support to
the USEPA's public meetings.  They handled support for the Dioxin
Reassessment Public Hearings in 1994.  I'm not sure what else they might
do.
Regards,
Mike Eckstein - New Jersey Agent Orange Commission

----------
> From: Tony Tweedale <ttweed@wildrockies.org>
> To: Multiple recipients of list DIOXIN-L <dioxin-l@essential.org>
> Subject: interesting EPA Workshop on Exposure-Duration
> Date: Friday, July 24, 1998 12:32 AM
> 
> nice to see EPA looking into this area of toxicology, though it's going
to
> take decades to investigate this question fully, and I supose it could be
> used to politicise risk assessments one way or the other.  Anyone know of
> this Eastern Research Group, Inc.?
> ---
> 
> [Federal Register: July 23, 1998 (Volume 63, Number 141)]
> [Notices]
> [Page 39568-39569]
> >From the Federal Register Online via GPO Access [wais.access.gpo.gov]
> [DOCID:fr23jy98-62]
> 
> -----------------------------------------------------------------------
> 
> ENVIRONMENTAL PROTECTION AGENCY
> 
> [FRL-6128-2]
> 
> 
> Technical Workshop on Exposure-Duration and Toxicity
> Relationships
> 
> AGENCY: Environmental Protection Agency (EPA).
> 
> ACTION: Notice of meeting.
> 
> -----------------------------------------------------------------------
> 
> SUMMARY: EPA is announcing a meeting organized and convened by Eastern
> Research Group, Inc., a contractor to EPA's Risk Assessment Forum, for
> external scientific peer consultation on the relationship of exposure-
> duration and toxicity. The meeting is being held to discuss methods
> under development or currently in use by EPA to characterize exposure-
> duration relationships and to explore how to model these relationships
> with respect to risk assessment.
> 
> DATES: The meeting will begin on Wednesday, August 5, 1998 at 8:30 a.m.
> and end on Thursday, August 6, 1998 at 5:00 p.m. Members of the public
> may attend as observers.
> 
> ADDRESSES: The meeting will be held at the Sheraton Crystal City, 1800
> Jefferson Davis Highway, Arlington, Virginia 22202. Since seating
> capacity is limited, please contact Eastern Research Group, Inc., Tel.:
> (781) 674-7374, or E-mail confmail@erg.com, by July 27, 1998 to attend
> the meeting as an observer.
> 
> FOR FURTHER INFORMATION CONTACT: For technical inquires, contact Dr.
> Gary Kimmel, U.S. EPA, Office of Research and Development (8623-D) U.S.
> EPA, 401 M Street S.W., Washington DC., 20460. Tel.: (202) 564-3308.
> 
> SUPPLEMENTARY INFORMATION: Current risk assessment procedures are
> typically based on overall daily exposure levels, and tend to emphasize
> effects resulting from continuous exposures over a lifetime. This basis
> is widely recognized to be an oversimplification, and there has been an
> increasing realization that exposures are more likely to be experienced
> as bursts or spikes, or intermittent exposures of varying levels. The
> complexities of exposure effects on toxic responses require
> consideration of the entire exposure profile, including the timing,
> duration, and intermittent nature of exposures reflecting realistic
> scenarios encountered in practical
> 
> [[Page 39569]]
> 
> settings. The proper metric for exposure may be highly dependent on the
> pharmacokinetic properties of the chemical or exposure in question, and
> the toxic effects considered in models must be carefully chosen to
> reflect the sensitive endpoints based on the exposure characteristics.
> Models have been developed over the last decade which begin to address
> the effect of duration of exposure in addition to exposure levels;
> however, most of these models do not incorporate mechanistic
> information. In addition, only limited work has been done on developing
> efficient designs for studying dose-rate effects, and these designs
> tend to be simplistic.
>     The Agency's Risk Assessment Forum is beginning to examine how
> exposure-duration and toxicity relationships are or can be incorporated
> into the risk assessment process for less-than-lifetime exposures. This
> examination is an extension of efforts within EPA as well as
> collaborative work carried out with researchers from the Harvard School
> of Public Health. The next step in this examination of exposure-
> duration and toxicity relationships will build upon these prior efforts
> through a peer consultation workshop.
>     The workshop is being held for invited participants to discuss the
> current understanding of dose-duration relationships and their
> underlying mechanistic basis, which approaches can be used in modeling
> these relationships, and how to include these methods in risk
> assessment, and future directions in this area. During the meeting,
> several presentations will be made to provide specific examples of the
> various issues. The remainder of the meeting will be organized around
> breakout sessions that will discuss where current risk assessment
> approaches may be improved.
> 
>     Dated: July 17, 1998.
> William H. Farland,
> Director, National Center for Environmental Assessment.
> [FR Doc. 98-19654 Filed 7-22-98; 8:45 am]
> BILLING CODE 6560-50-P
> 
> 
> 
> ------------------------------
>