Since honey bees roam a lot, they are ideal for capturing small parts of the world along the way. The body of the bee is covered with hair that carries small particles that the bee collects on purpose or simply encounters it while traveling. These filaments are electrostatically charged in flight and attract particles. Pollen is the most visible substance that is crosslinked in these filaments. But also plant debris, wax, and even other bee pieces stick.
Now another material has been added to that list: plastic. Thirteen different synthetic polymers to be exact. This is evidenced by a Danish study on honey bees and microplastics. The research was published earlier this year in Macro Ecology.
It was already known that microplastics are widespread throughout the world. Scientists are still learning a lot about how they move through the atmosphere. Scientists say it is difficult to take samples and that most research on microplastics in the air so far has only been done at ground level.
Now honeybees, and all those hairy legs and bodies, seem to be a useful tool for better mapping the distribution of plastic fibers and wind-borne shrapnel. Thanks to the large numbers and extensive research area, honey bees can be used as live probes to gauge how microplastics are distributed around the world.
The scientists said: “This research shows for the first time the possibility of using honey bees as a biological indicator for the presence of microplastic particles in the environment.”
Young environmentalists
For decades, scientists have used bees to spot heavy metals, pesticides, air pollution and even radioactive fallout. Previous research on plastic-bee contact dates back to the 1970s and focused more on macromolecules than on microplastics.
For example, it has been shown that wallpaper bees, which are similar in size to European honey bees but live solo and are found all over the world, use their enormous lower jaws to cut crescent-shaped plastic, as they do with leaves and petals.
Scientists in Chile, Argentina, Canada and the United States have observed that wallpaper bees collect small pieces of bags, packaging and other plastic materials to line their nests. A study from the United States found that bees also cut nesting material from the plastic flags used to map or mark construction sites.
In the Danish study, scientists collected thousands of worker bees, all of them females, from nineteen apiaries. Nine of these are in central Copenhagen and ten in the suburbs and rural areas outside the city. Researchers extracted the bees directly from inside the hives. They did this in the spring, when colonies were being built. Since bees are in contact with plants, water, soil, and air, there is a good chance they come in contact with plastic. These are all places where microplastics accumulate. The collection team wore clothing made of natural fibers and took other precautions to avoid contamination of the bee specimen.
Bees were frozen for euthanasia. Then she was washed and scrubbed to remove particles stuck to her legs and body. With the help of microscope and infrared light, the particles were sorted according to size, shape and material.
Fifteen percent of the particles covered microplastics. 52 percent of that was splinters and 38 percent of that was fiber. The most common fibers were polyester, followed by polyethylene and polyvinyl chloride. The bees also picked up the natural cotton fibers.
City bees showed the largest number of plastic particles. This was expected, given that urban areas were known to have the highest concentration of plastic particles. Surprisingly, the concentrations of microplastics in suburban and rural bees were not significantly lower. According to the scientists, this indicates that the concentration of microplastics is evenly distributed over large areas by wind dispersion.
Roberto Rosal, professor of chemical engineering at Alcala University in Madrid and co-author of the study, wrote in an email: “ I was expecting rural bees to be cleaner than bees from central Copenhagen. . “But the large movement of small plastic particles provides an explanation.”
