A Troubling Discovery in Terrestrial Ecosystems
Scientists from the Universities of Sussex and Exeter have uncovered widespread microplastic contamination in land-based invertebrates. Their discovery raises serious concerns that Britain’s entire food chain could be at risk. The team analyzed hundreds of insect and worm samples to reach this conclusion. Their research shows that plastic pollution doesn’t just affect the oceans anymore. It now threatens soil ecosystems—and could also harm human health.
Unveiling the Scale of Contamination
In this study, researchers examined over 580 invertebrates collected from 51 sites across Sussex. The results were deeply unsettling: microplastic fragments were present in nearly 12% of all bugs tested. Even more troubling, earthworms showed the highest contamination levels at 30%, with slugs and snails close behind at 24%. Notably, the most common type of plastic found was polyester—likely originating from synthetic clothing and entering the soil through sources such as dried sewage sludge used as fertilizer.
Microplastics Climbing the Food Web
Moreover, the contamination extended beyond herbivores and detritivores (organisms that feed on decaying plant matter). Carnivorous insects like ladybirds also tested positive for microplastics, having likely ingested them through contaminated prey. This clearly demonstrates that microplastics are moving up the food web—from the lowest levels to higher predators—posing a cumulative risk throughout the ecosystem.
Serious Implications for Biodiversity and Health
The consequences of these findings are far-reaching. Past studies have linked plastic ingestion in animals to stunted growth, reduced fertility, and organ dysfunction, affecting the liver, kidneys, and digestive tract. Since invertebrates form a foundational food source for birds, hedgehogs, and other mammals, this new evidence heightens concerns over long-term impacts on biodiversity and the stability of entire ecosystems.
A Call for Broader Focus and Immediate Action
Professor Fiona Mathews, an environmental biologist at the University of Sussex, stressed that microplastics are now “ubiquitous at every level of the food web.” The researchers argue that efforts to combat plastic pollution must move beyond targeting visible litter. Instead, greater attention should be directed toward hidden contributors, such as synthetic clothing fibres and microscopic paint particles.
Ultimately, this study underscores the urgent need for both a broader scientific focus on how microplastics affect terrestrial ecosystems and stronger policy actions to reduce plastic pollution at its source.
