The PRTF will be presenting at the Fall 2023 American Chemical Society meeting. Read the abstract and session information below.

Estimating the exposure of pesticide residues in nectar and pollen to bee pollinators

Tim Fredricks¹, Ana Cabrera¹, Max Feken², Daniel Schmehl¹, Silvia Hinarejos³, Timothy Joseph⁴, Bridget O’Neill⁵, Rajwinder Singh⁶

¹ Bayer CropScience LP, 700 Chesterfield Pwky. W., Chesterfield, MO 63017, USA
² Syngenta Crop Protection LLC, 410 Swing Road, Greensboro, NC 27409, USA
³ Sumitomo Chemical, Saint Didier au Mont d'Or, France
⁴ Mitsui Chemicals Agro, Inc. c/o Landis International, Inc., 3185 Madison Highway, Valdosta, GA 31603, USA
⁵ Corteva Agriscience, 9330 Zionsville Rd., Indianapolis, IN 46268, USA
⁶ BASF Agricultural Solutions, 26 Davis Drive, Research Triangle Park, NC 27709, USA

A pesticide registration requires a risk assessment that considers both toxicity and exposure to pollinators. Toxicity is defined as the dose that causes an adverse effect, while exposure – we will focus on dietary – considers the pesticide concentration in the diet (i.e., nectar and pollen) and the amount of diet consumed. The magnitude and duration of pesticide exposure vary widely according to plant type and bee attractiveness, physio-chemical properties, application rate, method and timing, and soil type. Regulatory authorities rely upon model-generated estimates to characterize exposure when measured pesticide residue data are unavailable. These theoretical pesticide residue estimates in pollen and nectar are based on T-REX model tall grass values (foliar applications), and the Briggs plant-soil uptake model (soil applications). The Pollinator Research Task Force analyzed systemic and non-systemic pesticide residue data from nectar and pollen samples collected across multiple studies that were submitted to United States Environmental Protection Agency (USEPA) and the European Food Safety Authority (EFSA). Our goal is to provide a statistically-refined pesticide residue estimation in the form of an interactive calculator. These results will strengthen the exposure component of pesticide risk assessment for bee pollinators by utilizing a robust pesticide residue data set of pollen and nectar samples covering various use patterns.

Session: Transitioning from the Laboratory to the Landscape: Challenges and Opportunities
Organizers: John Purdy, Jennifer Collins, Tom Steeger, Katrina White
Purpose: Pollinator research has uncovered many indications of adverse effects of pesticides, and many research papers in the field refer to population declines, but few refer to standard methods (e.g., OECD acute and chronic Test Guidelines) nor explain how results have been extrapolated from the lab to the landscape. It is widely assumed that pesticides are a major cause of pollinator declines despite the rigorous regulatory risk assessment process that relies on standardized assessment methods and is based on rigorously reviewed data submitted to support regulatory decisions as well as published research. This symposium will survey efforts to integrate new approach methods with established guidelines, and to facilitate extrapolations across multiple levels of biological organization. It is focused mainly on social and solitary bees, in view of their importance as pollinators. This symposium will be of interest to members of the AGFD, ANYL, ENVR and TOXI Divisions.