A new study has found that microplastics, once swallowed by earthworms, do not leave the digestive tract. This discovery, published recently by researchers, sheds light on a critical pathway for plastic pollution in soil ecosystems.
Earthworms are essential for soil health, aerating and mixing organic matter. The finding that these creatures retain microplastics has implications for the broader food web, as birds and other predators that eat earthworms could accumulate plastic particles.
The research adds to a growing understanding of microplastic fate in the environment. Globally, humanity now produces 450 million tonnes of plastic annually, with nearly one-quarter ending up in the environment, where they slowly break down into microscopic pieces.
These results suggest that microplastic contamination in soil may be more persistent than previously thought. The particles could affect earthworm health and reproduction, though the study did not measure long-term impacts on the organisms.
Further investigation is needed to determine whether microplastic accumulation in earthworms poses risks to higher trophic levels or to agricultural soils where these worms are abundant.