Bad Buzz: Microplastics Are Affecting Bee Cognition

The dangers of microplastics seeping into water, soil, and other locations along the environmental chain are well known by now. But researchers are increasingly sounding the alarm on the effect of the ubiquitous material on one of the most important cogs in Earth’s machine: bees.

The Washington Post recently highlighted a number of studies demonstrating mounting evidence that microplastics can have serious consequences on both bees and their attempts at pollination. The most significant concern relates to how these contaminants can impact a bee’s cognitive abilities: When inhaled, plastics can confuse bees, making their journey to pollinate difficult and impacting their memory of where they should be going.

One of the more remarkable studies was published in Science of the Total Environment in 2024, in which honeybees were fed a “diet” of microplastics and observed under imaging. The microplastics were able to cross the blood-brain barrier, resulting in learning and memory impairment. Bees taught to associate certain smells with a reward forgot the connection after microplastics were added to the lesson. And this was only with acute exposure. Long-term toxicity may be associated with even worse outcomes.

A 2024 meta-analysis found that microplastics and nanoplastics could be identified in bee guts outside of control settings. The contaminants disrupted their ability to pollinate; the analysis also noted that some bees use microplastics to build nests.

Nor does bee species seem to matter: Both honeybees (Apis mellifera) and bumblebees (genus Bombus) appear to be susceptible.

Bees can also ingest microplastics when nectar is contaminated. Combinations of plastics can prove fatal, with one study documenting a microplastics dosage commonly found in the environment increased mortality by 25 percent. Those that can survive the toxicity can still suffer, losing weight and hair and becoming more susceptible to pathogens. Exposure to plastics may even change the bees’ gene expression so that it weakens their immune systems.

Bees can be exposed to microplastics in a number of different ways. When materials only partially degrade in water or soil, they can pollute those resources, leading to exposure for bees as well as every other type of living creature. There’s also little doubt bees are in danger outside of laboratory settings: One 2021 study identified microplastics sticking to bee bodies, including their wings. Interrupting pollination could have dire consequences for agriculture, which is dependent on pollinators for sustainability.

It’s yet another reason environmental advocates continue to push for greater restrictions around microplastics as well as community efforts to reduce plastic waste. The TrashBlitz app, for example, encourages national park visitors to identify and contain leftover trash. The vast majority of waste logged in the parks consists of plastic bottles.

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