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November 30 - December 1, 2004 Meeting Agenda

November 17, 2004

FIFRA SCIENTIFIC ADVISORY PANEL (SAP)
OPEN MEETING
November 30 - December 1, 2004
FIFRA SAP WEB SITE http://www.epa.gov/scipoly/sap/
OPP Docket Telephone: (703) 305-5805
Docket Number: OPP-2004-0320

TUESDAY, NOVEMBER 30, 2004
Holiday Inn Rosslyn at Key Bridge
1900 North Fort Myer Drive
Arlington, VA 22209
(703) 807-2000

DIMETHOATE: ISSUES RELATED TO HAZARD AND DOSE RESPONSE ASSESSMENT

∙ 8:30 A.M. Introduction and Identification of Panel Members - Stephen M. Roberts, Ph.D. (FIFRA SAP Chair)
∙ 8:40 A.M. Administrative Procedures by Designated Federal Official - Ms. Myrta R. Christian
∙ 8:45 A.M. Welcome - Mr. Joseph J. Merenda, Jr. (Director, Office of Science Coordination and Policy, EPA)
∙ 8:50 A.M. Opening Remarks - Randolph Perfetti, Ph.D. (Health Effects Division, Office of Pesticide Programs, EPA)
∙ 8:55 A.M. Introduction and Background - Diana Locke, Ph.D. (Health Effects Division, Office of Pesticide Programs, EPA)
∙ 9:05 A.M. PMRA/EPA Collaboration - Ms. Cheryl Chaffey (Pest Management Regulatory Agency, Canada)
∙ 9:15 A.M. Hazard Characterization: Pup Mortality and Cholinesterase Inhibition Results - Kathleen Raffaele, Ph.D. (Health Effects Division, Office of Pesticide Programs, EPA)
∙ 10:00 A.M. BREAK
∙ 10:15 A.M. Benchmark Dose Analyses - Mr. Philip Villanueva (Health Effects Division, Office of Pesticide Programs, EPA)
∙ 10:45 A.M. Integration of Hazard and Dose Response Analyses - Kathleen Raffaele, Ph.D. (Health Effects Division, Office of Pesticide Programs, EPA)
∙ 12:00 P.M. LUNCH
∙ 1:00 P.M. Public Comments
∙ 3:00 P.M. BREAK
∙ 3:15 P.M. Public Comments (continued)
∙ 5:00 P.M. ADJOURNMENT

 

FIFRA SCIENTIFIC ADVISORY PANEL (SAP)
OPEN MEETING
November 30 - December 1, 2004
FIFRA SAP WEB SITE http://www.epa.gov/scipoly/sap/
OPP Docket Telephone: (703) 305-5805
Docket Number: OPP-2004-0320

WEDNESDAY, DECEMBER 1, 2004
Holiday Inn Rosslyn at Key Bridge
1900 North Fort Myer Drive
Arlington, VA 22209
(703) 807-2000

DIMETHOATE: ISSUES RELATED TO HAZARD AND DOSE RESPONSE ASSESSMENT
∙ 8:30 A.M. Introduction and Identification of Panel Members - Stephen M. Roberts, Ph.D. (FIFRA SAP Chair)
∙ 8:40 A.M. Administrative Procedures by Designated Federal Official - Ms. Myrta R. Christian
∙ 8:45 A.M. Follow-up from Previous Day's Discussion
- Kathleen Raffaele, Ph.D. (Health Effects Division, Office of Pesticide Programs, EPA)
- Ms. Cheryl Chaffey (Pest Management Regulatory Agency, Canada)
∙ 9:00 A.M. Questions to the Panel

Interpretation of the cholinesterase activity and pup mortality results from the dimethoate developmental neurotoxicity (DNT) study and related studies.

Question 1.1

Please comment on the information available for dimethoate which characterizes the underlying cause(s) of the pup mortality in the dimethoate DNT study and the degree to which this information can be used to determine the impact of maternal neglect/maternal toxicity on pup mortality. [Section II B and Sections II C 2, 3, 5b-d]

∙ 10:00 A.M. BREAK
∙ 10:15 A.M. Questions to the Panel (continued)

Question 1.2

The results of the cross fostering study suggest that the pup mortality observed at lower doses in the main DNT study may not be attributable to a single dimethoate exposure. Please comment on the evidence that supports or refutes this analysis. [Section II B 2 and II C 5 d]

Question 1.3

After considering the results of the BMD analyses for brain ChE inhibition and for pup mortality, it is proposed that brain ChE inhibition be used as the endpoint for the dimethoate risk assessment for all durations of exposure (e.g., acute, chronic). This would also be protective for the pup mortality endpoint, because available data indicate that brain ChE inhibition occurs at doses similar to or lower than those causing increases in pup mortality. A number of factors were considered in developing this proposal:

❏ Brain ChE inhibition occurs at doses similar to or lower than those causing ChE inhibition in other compartments;

❏ BMD analyses results indicate a very robust dose-response curve for brain ChE inhibition, with similar BMD10 values from studies with varying modes of administration (dietary or gavage) and durations (short term for DNT studies and longer term for reproduction studies);

❏ BMD analyses results indicate similar dose-response curves at all ages, with no difference in BMD10 values for different age groups following similar exposure durations;

❏ Comparison of BMR dose levels for brain ChE inhibition and pup mortality following repeated dosing indicates that ChE inhibition occurs at doses similar to those associated with increases in pup mortality;

❏ Evaluation of pup mortality data from the cross-fostering study reveals clear increases in mortality only at the highest dose following short-term exposure, indicating that increased mortality at lower doses occurs only with repeated dosing;

❏ Comparison of the NOAEL for increased pup mortality from limited dosing with the BMD10 for brain ChE inhibition following a single dose indicates that brain ChE inhibition occurs at doses below those causing a clear increase in pup mortality.

Please comment on the evidence that supports or refutes this proposal (Sections IIB 4, and II C).

∙ 12:30 P.M. ADJOURNMENT


Please be advised that agenda times are approximate. For further information, please contact the Designated Federal Official for this meeting, Ms. Myrta Christian, via telephone: (202) 564-8450; fax: (202) 564-8382; or email: christian.myrta@epa.gov


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