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Research article2021Peer reviewedOpen access

Pesticides in honey bee colonies: Establishing a baseline for real world exposure over seven years in the USA

Traynor, Kirsten S.; Tosi, Simone; Rennich, Karen; Steinhauer, Nathalie; Forsgren, Eva; Rose, Robyn; Kunkel, Grace; Madella, Shayne; Lopez, Dawn; Eversole, Heather; Fahey, Rachel; Pettis, Jeffery; Evans, Jay D.; vanEngelsdorp, Dennis


Honey bees Apis mellifera forage in a wide radius around their colony, bringing back contaminated food resources that can function as terrestrial bioindicators of environmental pesticide exposure. Evaluating pesticide exposure risk to pollinators is an ongoing problem. Here we apply five metrics for pesticide exposure risk (prevalence, diversity, concentration, significant pesticide prevalence, and hazard quotient (HQ)) to a nation-wide field study of honey bees, Apis mellifera in the United States. We examined samples from 1055 apiaries over seven years for 218 different pesticide residues and metabolites, determining that bees were exposed to 120 different pesticide products with a mean of 2.78 per sample. Pesticides in pollen were highly prevalent and variable across states. While pesticide diversity increased over time, most detections occurred at levels predicted to be of low risk to colonies. Varroacides contributed most to concentration, followed by fungicides, while insecticides contributed most to di-versity above a toxicity threshold. High risk samples contained one of 12 different insecticides or var-roacides. Exposures predicted to be low-risk were nevertheless associated with colony morbidity, and low-level fungicide exposures were tied to queen loss, Nosema infection, and brood diseases.(c) 2021 Published by Elsevier Ltd.


Apis mellifera; Pollen; Pesticides; Exposure risk; Colony morbidity

Published in

Environmental Pollution
2021, Volume: 279, article number: 116566

    UKÄ Subject classification

    Environmental Sciences

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