National Exposure Research Laboratory Research Abstract Provide OPPTS and the Regions with an Upgraded PRZM for Use in Characterizing Ecological Risks


I ii i (I'd Slides limimnmenlal Pro loci ion .\»enc\	Office of Research ;iikI l)o\ olopmoiil

National Kxposure Research Laboratory
Research Abstract

Government Performance Results Act (GPRA) Goal #4.5
Annual Performance Measure #227

Significant Research Findings:

Provide OPPTS and the Regions with an Upgraded PRZM for use
	in characterizing ecological risks	

Scientific	EPA's Office of Pesticide Programs (OPP) and the regulated community make

Problem and	extensive use of a suite of ORD models for assessing pesticide exposure in the

Policy Issues	environment: PRZM/VADOFT, EXAMS, AgDrift, and BASS/FGETS. Design

specifications for expanding these models to accommodate the needs for pesticide
safety evaluations mandated by the Food Quality Protection Act (FQPA, 2006)
and to incorporate probabilistic measures of risk at regional and continental scales
are under development. Ongoing discussions with OPP scientists ensure that
future ORD products are relevant and timely to support regulatory actions.

The modeling research under this task involves software modernization (in respect
to both Information Sciences and ecotoxicology), validation status examinations,
and integration of the existing suite of EPA pesticide fate and transport models
into a decision support system suitable for the full range of the Federal Insecticide,
Fungicide, and Rodenticide Act (FIFRA) and FQPA regulatory analyses. The
databases needed to tailor the modeling system to the biogeographic particulars of
individual regulatory submissions are being developed, along with probabilistic
scenario management tools needed to accomplish risk assessments. OPP's
Environmental Fate and Effects Division (EFED) has peer reviewed PRZM
version 3.12.2, an upgraded model version based on the earlier PRZM v3.12.p.
EFED developed a suite of pesticide scenarios and evaluated the results obtained
through PRZM v3.12.2. The results from PRZM 3.12 p were the standard against
which later versions were compared. The value of the output variables pesticide
flux in runoff and water balance (among others) were compared against the PRZM
3.12 p results.

As requested by EFED, PRZM version 3.12.2 has replaced PRZM version 3.12.p
on the Center for Exposure Assessment Modeling site. This model is readily
accessible for regulatory use by agency risk assessors and the regulated
community. The PRZM manual has been updated with several corrected items,
and the PRZM source code and manual have been synchronized. OPP/EFED will
benefit by having a more robust and well-documented exposure model, leading to
improvements in the accuracy of pesticide risk assessments and regulatory
decisions.

Research
Approach

Results and
Impact

Research

Examples of recent publications from this study include:

-------
Collaboration and Suarez, L.A. "PRZM-3, A Model for Predicting Pesticide and Nitrogen Fate in the Crop Root and
Research	Unsaturated Soil Zones: Users Manual for Release 3.12.2," 2005.

Products	Burns, L. A., Suarez, L.A., and Prieto, L. "United States Meteorological Data: Daily and Hourly

Files to Support Predictive Exposure Modeling." U.S. Environmental Protection Agency,
Athens, Georgia. In review, 2005.

Future Research Development of a testing suite for PRZM, in preparation for software
modernization, is underway.

Contacts for	Questions and inquiries can be directed to:

Additional

Information	Luis a. Suarez, Ph.D.

U.S. EPA, Office of Research and Development
National Exposure Research Laboratory
960 College Station Road
Athens, GA 30605-2700
Phone: 706/355-8108
E-mail: suarez.luis@epa.gov

Funding for this project was through the U.S. EPA's Office of Research and
Development, National Exposure Research Laboratory, and the work was
conducted by the Ecosystems Division.

-------