Protecting pollinators: moving towards an ecologically integrated risk assessment framework.

Abstract

The current environmental risk assessment framework for pesticides remains anchored to inadequate metrics and approaches. Although regulatory bodies incorporated chronic toxicity studies and developed advanced guidance, critical gaps in implementation undermine their effectiveness. Among these gaps are 1) continued primacy of the acute median lethal dose as a trigger for higher-tier assessments, 2) lack of standardized sublethal endpoints, 3) inadequate consideration of chemical mixtures, and 4) near-exclusive reliance on Apis mellifera as a surrogate for pollinator communities. Further, interactions between pesticides and other environmental stressors are not systematically assessed. This review critically examines the limitations of the current paradigm and proposes a structured, ecologically integrated framework for modernizing pollinator risk assessment. This review outlines 7 pillars: 1) taxonomic diversification of test species, 2) mandatory inclusion of chronic and sublethal endpoints at Tier 1, 3) standardization of sublethal behavioral assays, 4) tiered assessment of pesticide mixtures incorporating increasingly realistic ecological scenarios, 5) incorporation of landscape-scale exposure modeling, 6) explicit integration of multi-stressor interactions, and 7) in silico models to link individual-level effects to colony and population outcomes. While acknowledging the significant investment required, it is postulated that a phased transition is scientifically necessary and economically prudent, given the indispensable value of pollination services to global agriculture and ecosystem stability.