American Chemical Society Fall 2011 National Meeting & Exposition

Transcription

1 American Chemical Society Fall 2011 National Meeting & Exposition Overview of Issues in Aquatic Exposure Modeling in the US EPA Office of Pesticide Programs, Environmental Fate and Effects Division Donald Brady, Ph.D - Director Presented by Ronald Parker Evaluating Agrochemical Aquatic Exposure Modeling in Relation to Risk Evaluator Needs

2 Summary of Current Activities in EFED Aquatic Exposure Modeling Overall Efforts to Improve Time Efficiency in EFED Modeling Enhanced Use of Spatial Assessment Capabilities Release of New Set of Percent Cropped Area (PCA) Values for Drinking Water Exposure Assessment Continuing to Develop Our Capabilities in Modeling of Groundwater with Canada

3 Summary of Current Activities in EFED Aquatic Exposure Modeling Finalization of Methodology for Assessment of PBT-like Pesticides (Follow-up of Scientific Advisory Panel Recommendation) Issuance of Guidelines for Pesticide Degradation Calculation with Canada Finalizing Our Efforts to Enhance Exposure Assessment for Pesticide Rice Application

4 Enhanced Use of Spatial Modeling Capabilities Enhanced Use of Spatial Capabilities Spatial Aquatic Model (SAM) Pilot Project Pilot Project Began in May Development of Faster PRZM for National Level Spatial Assessments Use of GIS Methodology for PRZM Scenario Development Take Advantage of Storage Capacity for Spatial Model Inputs and Outputs Super Scenarios

5 Enhanced Use of Spatial Modeling Capabilities Spatial Distribution of Species Compare with Spatial Exposure Distribution Focus on Parameters of Importance to Exposure Modeling and Effects Extrapolation Development of a Modeling Ubertool Run Multiple EFED Models with One Setup Increased Integration of Databases into Modeling

6 Current Issues in EFED Aquatic Exposure Modeling Continuing to Build on Coordination with other EPA Programs EPA Office of Water EPA Regional Offices Continuing to Build on Coordination with other Federal Government Agencies USGS (NAWQA) USDA (PDP) NMFS and FWS (ESA) International Work Joint Global and NAFTA Reviews Training, e.g. Brazil, China, etc.

7 Integration of SAM with an UberTool Desktop Tool (or Web-based Tool) Aquatic and Terrestrial Model Inputs from Databases Non-spatial Data Links Label Uses, Application Rates Pesticide Fate/Transport Properties Data Storage/Database Links Integrate Exposure Outputs with Toxicity Magnitude, Frequency, Duration of Exceedance Spatial Overlap (Where Available) What-if, Mitigation Capabilities 7

8 Registration Review Integration Tool- May 2011 OPPINTool Complete, ready for Problem Formulation Testing. Luis Tool pending, present method relies on Luis Table Current scenario-based model is complete NW Pilot commencing for spatially explicit version Nationwide Spatially explicit Under initial development AgDrift complete Kabam Complete Geneec Complete RICE Tier 1 complete Tier 2 50% First version for Draft Registration review reports 90% complete QA/QC/Manual efforts pending FESTF efforts underway for biological and Species proximity associations.. FESTF proximity tool is complete but requers settling on spatial scale and land cover. Biological data from FESTF is at 5% completion as is in pilot stage In-house analogous process conceptualized OPPIN and LUIS Access Tools Use site, application info, land cover Chemical ID Existing TerrPlant model complete. TREX complete, minor modifications to TREX in 6 months. SIP PF model complete, Tier 1 model not begun STIR PF model complete Tier 1 model in initial stage AgDrift complete Incorporated into OPPIN Tool Task complete Incorporated into Downstream tool Incorporated into FESTF output for species association FESTF efforts underway for biological and Species proximity associations.. FESTF proximity tool is complete but requers settling on spatial scale and land cover. Biological data from FESTF is at 5% completion as is in pilot stage In-house analogous process conceptualized

9 New National Representation of PCAs Final QA/QC 9

10 Metabolite Modeling with PRZM Formation phase kp*ffm*p>km*m where: kp=parent rate const. km=metab rate const. ffm=formation fraction of metabolite P=Amount of parent M=Amount of metab Substance (% of applied) Maximum kp*ffm*p=km*m Parent Decline phase km*m> kp*ffm*p Metabolite Time (days)

11 Metabolite Modeling with PRZM

12 PRZM-Based Modeling Tool for Groundwater with Canada Parameterized PRZM_GW for About 68 Compounds Used Most Recent DWA for Chemical Properties (Koc, Hydrolysis Half-lives, Aerobic Metabolism Half-lives) Maximum Application Rate Modeled Each Compound for Each of Seven Scenarios Delmarva, FL Citrus, FL Potato, GA peanuts, NC Cotton, WI Corn, ID Potato Compared Output to NAWQA Observed Peak Values