Earthworms Enjoy Eating Plastics, but the Consequences of Their Ingestion Remain Unknown: New Study

Gardeners and farmers appreciate earthworms because the writhing creatures recycle nutrients from the soil, rendering them more available to plants.

Worms eat practically everything in their path, even tiny plastic waste, as they burrow.

Earthworms prefer soil with particular types of microplastics, according to a new study published in the American Chemical Society's journal Environmental Science & Technology, although they metabolize the polymers differently, the team believed it might have an influence on the their health and the ecosystem.

Earthworms eating plastics

(Photo : ANNE-CHRISTINE POUJOULAT/AFP via Getty Images)

Plastic fragments, especially microplastics less than 5 mm wide that already have split off of larger plastic waste or been released directly from things as minute particles are polluting soil in increasing numbers.

According to ScienceDaily, studies have shown that earthworms would devour these synthetic particles, even breaking them down into smaller pieces.

Microplastics or the harmful substances they convey during in the process of digestion, on the other hand, may have an impact on animals.

Currently, firms are developing plant-based, biodegradable, or both alternatives to petroleum-based plastics.

These "bioplastics" can also break down into minute particles, much like regular plastics, but there's no way of knowing if earthworms would eat and degrade them.

When lactic acid and terephthalic acid, the moldy monomer that makes up PLA and PET, respectively, were spiked into the soil, the worms were drawn in.

This suggested that the creatures were drawn in by the odors as possible food signals.

More research is necessary to determine how well the slow discharge of PLA shards impacts the health of such living creatures as well as whether worms are a viable option for removing degradable plastics from the environment, according to researchers.

Also Read: New Research Reveals Earthworms Can Replace Expensive Synthetic Fertilizers

Can they clean up our mess?

Federica Bertocchini, a developmental biologist at the University of Cantabria in Spain, headed the research team, as per the National Geographic.

When she was cleaning out her backyard bee hives two years ago, she became aware of the possibilities.

She took out a few wax worms (Galleria mellonella) from the hive and put them in an old plastic bag.

She also observed small holes in the region where the larvae were when she studied the bag an hour later.

Bertocchini collaborated with other scientists Paolo Bombelli and Christopher Howe to discover how wax worms ate plastic.

They discovered that each worm generated an average of 2.2 holes per hour when they placed them on polyethylene plastic, and that 100 wax worms decomposed 92 milligrams of plastic grocery bags in one night.

At this rate, 100 worms would take nearly a month to completely break down a typical 5.5-gram plastic bag.

The researchers used a soupy mixture of freshly killed worms on the plastic to rule out gnawing action from their teeth as the source of degradation.

They discovered that the liquid larvae could chew holes in plastic as well.

This indicated to Bertocchini and colleagues that the plastic was being dissolved by an enzyme in the worms or bacteria residing in and on their bodies.

Polyethylene was transformed to ethylene glycol, a substance often used in antifreeze, by this enzyme. In the future, Bertocchini aims to discover the specific enzymes which break down polyethylene.

 Related article: Microplastics: The 'Missing Plastics' of the Ocean Uncovered by Scientists