Ecotoxicity of Pesticides Approved for Use in European Conventional or Organic Agriculture for Honeybees, Birds, and Earthworms

Pesticides affect biota inside and outside agricultural fields due to their intrinsic mode of action. This study investigated whether pesticide active substances (AS) approved for conventional agriculture in Europe differ in their ecotoxicity from AS approved for organic agriculture. The evaluation was based on official ecotoxicological data for surrogate honeybee, bird, and earthworm species, which also serve as a reference for official environmental risk assessments in the pesticide authorization process. In October 2022, 268 chemical-synthetic AS approved for conventional and 179 nature-based AS approved for organic agriculture were listed in the EU Pesticide Database. Ecotoxicological data were only available for 254 AS approved for use in conventional agriculture and 110 AS approved for use in organic agriculture. The results showed a higher ecotoxicity of conventional AS: 79% (201 AS), 64% (163 AS) and 91% (230 AS) were moderately to acutely toxic to honeybees, birds, and earthworms, respectively, compared to 44% (48 AS), 14% (15 AS) and 36% (39 AS) of AS approved for organic agriculture. We have only considered the potential ecotoxicities of individual substances in this assessment; actual exposure in the field, where multiple AS formulations with other chemicals (including impurities) are applied, will be different. Nevertheless, these results emphasize that an increase in organic agriculture in Europe would reduce the ecotoxicological burden on biodiversity and associated ecosystem services.