What Pollen Stores Reveal About Trace-Element Exposure in Different Bees

The full story

What Happened? [1] [2] [3]

Researchers examined 18 trace elements in stored pollen collected by western honey bees, buff-tailed bumble bees, and red mason bees at 128 apple-orchard and oilseed-rape sites in eight European countries. They also analyzed honey bee workers and used the pollen measurements to estimate dietary exposure. [1] [2] [3]

The clearest pattern was species-specific: red mason bee pollen stores contained several-fold higher concentrations of many trace elements than the pollen stores of honey bees or bumble bees. The authors say this means honey bees may be an incomplete stand-in for other pollinators, especially solitary bees. [1] [2] [3]

Why Should We Care? [1] [2]

Bees do not all encounter their environment in the same way. A monitoring program based only on honey bees could miss important differences in what other pollinators bring back to their nests. [1] [2]

The study also found that pollen from apple-orchard sites had higher copper concentrations than pollen from oilseed-rape sites. The researchers describe copper-based fungicides as a likely explanation, while emphasizing that exposure patterns can reflect multiple pathways, including bee ecology, crops, and surrounding landscape. [1] [2]

What Did the Researchers Find?

The team measured 18 trace elements in stored pollen from three bee species at 128 agricultural sites across Estonia, Sweden, Ireland, the United Kingdom, Germany, Switzerland, Italy, and Spain. [1] [2]
Red mason bee pollen stores had several-fold higher concentrations of many trace elements than pollen stores from honey bees and bumble bees. [1] [2] [3]
Stored pollen from apple-orchard sites had higher copper concentrations than pollen from oilseed-rape sites; the authors identify copper-based fungicides as a likely contributing source. [1] [2]
Crop and urban land cover were among the landscape characteristics associated with variation in trace-element concentrations in stored pollen and honey bee workers. [1] [2]
For trace elements with usable bee-toxicity endpoints, the study’s dietary-risk estimates were negligible or low; for many other elements, risk could not be quantified because suitable toxicity data were unavailable. [1] [2] [3]

How Do We Know? [2] [1]

This was a multi-country field study rather than a laboratory dosing experiment. The researchers collected stored pollen from nests or colonies of three bee species in apple orchards and near oilseed-rape fields, measured 18 elements, and compared patterns by bee species, crop setting, and landscape characteristics. Honey bee workers were also analyzed. [2] [1]

To explore possible dietary hazard, the team combined measured pollen concentrations with bee pollen-consumption assumptions and available toxicity thresholds. Those calculations are estimates of exposure and potential risk; they are not direct observations of illness, behavior, reproduction, or colony survival. [2] [1]

What Doesn’t This Study Prove?

It does not prove a single source for each element. The field data show differences among bee species, crops, and landscapes, but they do not by themselves trace every element to a particular source. Copper in orchard pollen was linked only cautiously to likely copper-fungicide use. [2] [1]

It does not show that measured exposure harmed bees. The study measured elements in pollen and modeled dietary exposure. It did not directly measure survival, reproduction, learning, immune function, or colony performance after those exposures. [2]

Low estimated risk is not a complete safety finding. Risk could be estimated only where suitable toxicity endpoints existed. The authors report substantial data gaps, particularly for non-honey-bee pollinators and possible sublethal effects. [2] [1]

The results should not be generalized to every bee or landscape. The field work focused on three managed bee species, two crop contexts, and 128 sites in eight European countries. Other species, nesting habits, regions, and farming systems may have different exposure patterns. [2] [1]

Where Did This Research Come From?

Research Record

Original Study: From flowers to pollinators: Dietary exposure of honey bees, bumble bees and solitary bees to trace elements across European fields
Authors: Maciej Durkalec; Agnieszka Nawrocka; Petru Jitaru; Marie-Pierre Chauzat; Marion Laurent; Matthias Albrecht; Cecilia Costa; Pilar De la Rúa; Alexandra-Maria Klein; Marika Mänd; Simon G. Potts; Maj Rundlöf; Oliver Schweiger; Irene Bottero; Elena Cini; Joachim R. de Miranda; Gennaro Di Prisco; Christophe Dominik; Simon Hodge; Reet Karise; Jessica Knapp; Anina Knauer; Vicente Martínez-López; Piotr Medrzycki; Helena Pereira-Peixoto; Risto Raimets; Janine Schwarz; Deepa Senapathi; Giovanni Tamburini; Mark J. F. Brown; Jane C. Stout; Tomasz Kiljanek
Journal: Journal of Hazardous Materials
Publisher: Elsevier B.V.
Publication: 2026-08-01
Honey Chronicles Timeline Date: Online publication
Online Publication Date: 2026-06-08
Journal Issue Date: 2026-08-01
Volume: 514
Pages / Article: 142644
Species Studied: Western honey bee (Apis mellifera); buff-tailed bumble bee (Bombus terrestris); red mason bee (Osmia bicornis)
Research Location / Affiliations: Field sites in Estonia, Sweden, Ireland, the United Kingdom, Germany, Switzerland, Italy, and Spain.
DOI: 10.1016/j.jhazmat.2026.142644