Evaluation of microplastic pollution using bee colonies: An exploration of various sampling methodologies

Area of Science:

• Environmental Science
• Analytical Chemistry
• Ecotoxicology

Background:

• Honeybees and bee products are recognized biological samplers for environmental pollutants.
• The efficacy of these natural samplers for detecting microplastics (MPs) remains unexplored.
• Microplastic pollution is a growing environmental concern requiring effective monitoring tools.

Purpose of the Study:

• To evaluate honeybees, pollen, and a novel in-hive passive sampler (APITrap) for microplastic detection.
• To compare the reliability and efficiency of different sampling methods for microplastics.
• To chemically identify polymer types of microplastics found in beehives.

Main Methods:

• Microplastics were sampled using honeybees, pollen, and the APITrap passive sampler across five Danish apiaries.
• Samples were analyzed via stereomicroscopy for MP quantification and categorization (morphology, color, type).
• Micro-Fourier transform infrared (FTIR) spectroscopy was used for chemical identification of polymer types.

Main Results:

• The APITrap demonstrated superior reproducibility (39% variation) compared to honeybee (111%) and pollen (97%) samples.
• APITrap detected significantly higher average MP counts (39-67) than honeybees (6-9) and pollen (6-11).
• Fibres constituted the majority (91%) of MPs, predominantly black, blue, green, and red, with identified polymers including PET, PP, PE, PAN, and PA.

Conclusions:

• The APITrap is a highly reliable and comprehensive tool for large-scale microplastic monitoring in beehives.
• This citizen science-supported method shows no adverse effects on bees and allows for successive sampling.
• The study confirms the accumulation of microplastics within beehive environments, highlighting the APITrap's potential for environmental surveillance.