Objective 1: To develop authoritative IUPAC Good Modeling Practice (GMP) guidelines for pesticide aquatic ecological exposure/risk assessment (ERA) and risk management. The GMP guidelines will serve a similar audience as the one which is served by pesticide Good Laboratory Practice (GLP) guidelines.
Objective 2: To prepare a paper for publication in Pure and Applied Chemistry and other publications and to develop presentations for IUPAC Congresses and/or ACS national conferences.
Objective 3: To disseminate the GMP guidelines on the IUPAC website where they may be useful to governmental pesticide authorities in making ecological risk assessment and risk management decisions to inform pesticide registration decisions.
Rationale: The development of international GMP guidelines is a critical need for improving standardization of approaches and increasing confidence by regulatory authorities in their utility for decision-making. Standard guidelines (including GLP guidelines) are followed in development of pesticide ecological effects laboratory estimates, but there are no similar guidelines to focus development of pesticide exposure estimates at agricultural field locations.
These GMP guidelines will include criteria for choice of field exposure models, methods of selecting of modeling input values, advice on documentation of model results and ways of estimating variability and expressing uncertainty in model output.
Pesticide ecological risk assessment (ERA) is a process that evaluates the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more pesticides. Relevant exposure concentrations are compared to laboratory effects (toxicity) concentrations as an indicator of potential risk.
In the ERA process, selecting relevant exposure concentrations may be difficult and complex, however, due to spatial and temporal variability of application and of weather across the area of usage. Computer modeling is useful in pesticide ERA because the processes of application and of fate and transport can be simulated so that variability in space (multiple fields) and time (multiple years) can be estimated. Variable weather, variable topography, variable soils, and variable management options can also be factored into the assessment. This extensive type of assessment, however, requires judgment in selecting exposure concentration values that are useful and relevant for risk management decision making across a wide area.
ERA processes are therefore concentrated largely in the government regulatory agencies of many countries, in industries that develop and market pesticides and in consultants the assist and/or facilitate this evaluation and registration process.
These GMP guidelines will be developed and compiled by experts with a range of expertise and experience in pesticide ecological exposure/risk assessment. The overall project will be divided into a range of subject areas, each of which will be addressed by an individual with appropriate experience. The task group will meet by phone conference regularly over a period of 8-10 months and will exchange draft materials within the group.
The final draft developed by the task group will be distributed to a range of other experts for critical evaluation of the methods and procedures developed by the task group. The evaluation group will include government regulatory experts and scientists from industry and the environmental community in order to receive feedback from those directly involved in the exposure/risk assessment process.
IUPAC is an ideal participant in this type of project because (1) the final result will combine the experience of many organizations which will include not only governments, but non-governmental organizations, consultants, private industry, and universities, and because IUPAC has a long history of working with international pesticide issues, (2) the wide range of available expertise from which it can draw.
1. Ecological Models for Regulatory Risk Assessments of Pesticides: Developing a Strategy for the Future,Â SETAC, edited by Pernille Thorbek, Valery E. Forbes, Fred Heimbach, Udo Hommen, Hans-Hermann Thulke, Paul van den Brink, JÃ¶rn Wogram, Volker Grimm, 2009.
2 Estes, T.L. The FIFRA Exposure Modeling Work Group: New Approaches for Predicting Exposure for Regulatory Purposes, in Proceedings of the International Exposure Symposium on Water Quality Modeling; American Society of Agricultural Engineers, pp. 475-484; Orlando, Florida; April, 1995.
Last update: 14 May 2018