Overcoming Challenges of Incorporating Higher Tier Data in Ecological Risk Assessments and Risk Management of Pesticides in the United States: Findings and Recommendations from the 2017 Workshop on Regulation and Innovation in Agriculture

Abstract

Pesticide regulation requires regulatory authorities to assess the potential ecological risk of pesticides submitted for registration, and most risk assessment schemes use a tiered testing and assessment approach. Standardized ecotoxicity tests, environmental fate studies, and exposure models are used at lower tiers and follow well‐defined methods for assessing risk. If a lower tier assessment indicates that the pesticide may pose an ecological risk, higher tier studies using more environmentally realistic conditions or assumptions can be performed to refine the risk assessment and inform risk management options. However, there is limited guidance in the United States on options to refine an assessment and how the data will be incorporated into the risk assessment and risk management processes. To overcome challenges to incorporation of higher tier data into ecological risk assessments and risk management of pesticides, a workshop was held in Raleigh, North Carolina. Attendees included representatives from the United States Environmental Protection Agency, United States Department of Agriculture, National Oceanic and Atmospheric Administration, universities, commodity groups, consultants, nonprofit organizations, and the crop protection industry. Key recommendations emphasized the need for 1) more effective, timely, open communication among registrants, risk assessors, and risk managers earlier in the registration process to identify specific protection goals, address areas of potential concern where higher tier studies or assessments may be required, and if a higher tier study is necessary that there is agreement on study design; 2) minimizing the complexity of study designs while retaining high value to the risk assessment and risk management process; 3) greater transparency regarding critical factors utilized in risk management decisions with clearly defined protection goals that are operational; and 4) retrospective analyses of success–failure learnings on the acceptability of higher tier studies to help inform registrants on how to improve the application of such studies to risk assessments and the risk management process. Integr Environ Assess Manag 2019;15:714–725. © 2019 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

A Simplified Population-Level Landscape Model Identifying Ecological Risk Drivers of Pesticide Applications, Part One: Case Study for Large Herbivorous Mammals

“…There are clear challenges for incorporating higher tier data in the risk assessment of pesticides [42]. The use of the model offers a set of benefits.…”

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Utility of the avian sub‐acute dietary toxicity test in ecological risk assessment and a path forward to reduce animal use

“…The proposed changes presented in this article are widely applicable across the majority of chemical classes and risk scenarios. All design changes should be discussed with regulatory authorities before conducting a sub‐acute dietary study as a refinement for an avian risk assessment (Levine et al, 2019 ).…”

“…In addition, for the alkyl sulfate, there was a dose‐dependent increase in mortality in the gavage study, with an LD50 value of 1612 mg/kg; however, no mortality was observed in the dietary study at the comparable and highest mean dose of 1574 mg/kg bw/day (Figure 1D ). Taken together, these four examples with surfactants show an important difference in the toxicity profile between gavage and dietary studies, and therefore, results from the dietary study could be used for risk refinement to further inform regulatory decision‐making (Levine et al, 2019 ).…”