Characterizing honey bee exposure and effects from pesticides for chemical prioritization and life cycle assessment

https://doi.org/10.1016/j.envint.2020.105642Get rights and content
Under a Creative Commons license
open access

Highlights

  • Model for quantifying pesticide field exposure and ecotoxicity effects of bees.

  • Integration of bee impacts in risk screening and life cycle impact assessment.

  • Defined bee intake and dermal contact fractions as novel metrics for exposure.

  • Case study on two pesticides on oilseed rape affecting 1260–1,360,000 bees/kg applied.

  • Nectar foragers are the most affected forager type, with 32–190 ppm pesticide intake.

Abstract

Agricultural pesticides are key contributors to pollinator decline worldwide. However, methods for quantifying impacts associated with pollinator exposure to pesticides are currently missing in comparative risk screening, chemical substitution and prioritization, and life cycle impact assessment methods. To address this gap, we developed a method for quantifying pesticide field exposure and ecotoxicity effects of honey bees as most economically important pollinator species worldwide. We defined bee intake and dermal contact fractions representing respectively oral and dermal exposure per unit mass applied, and tested our model on two pesticides applied to oilseed rape. Our results show that exposure varies between types of forager bees, with highest dermal contact fraction of 59 ppm in nectar foragers for lambda-cyhalothrin (insecticide), and highest oral intake fractions of 32 and 190 ppm in nectar foragers for boscalid (fungicide) and lambda-cyhalothrin, respectively. Hive oral exposure is up to 115 times higher than forager oral exposure. Combining exposure with effect estimates yields impacts, which are three orders of magnitude higher for the insecticide. Overall, nectar foragers are the most affected forager type for both pesticides, dominated by oral exposure. Our framework constitutes an important step toward integrating pollinator impacts in chemical substitution and life cycle impact assessment, and should be expanded to cover all relevant pesticide-crop combinations.

Keywords

Honey bees
Pesticide residues
Exposure modelling
Chemical prioritization
Chemical substitution
Life cycle impact assessment

Cited by (0)

1

Present address: Technology and Society Laboratory, Empa, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.