A recent study suggests that bio-based fibers, such as viscose and lyocell, may pose a higher risk to earthworms and soil health than traditional polyester fibers.
Bio-based materials, often hailed as environmentally friendly alternatives to traditional plastics, may pose a significant health risk to vital species such as earthworms, according to a new study published in Environmental Science & Technology.
Researchers from the University of Plymouth and the University of Bath conducted experiments to compare the effects of conventional polyester fibers against bio-based fibers, including viscose and lyocell, on earthworms. Earthworms play a crucial role in maintaining soil health and biodiversity around the globe.
The study showed alarming results: in high concentrations, conventional polyester fibers resulted in a 30% mortality rate among earthworms after 72 hours. In contrast, bio-based fibers led to much higher mortality rates, with 60% of earthworms dying when exposed to lyocell and 80% when exposed to viscose fibers.
The study also looked at more realistic, environmentally relevant concentrations of these fibers. Earthworms in soils with viscose fibers displayed reduced reproduction rates compared to those exposed to polyester fibers. Additionally, lyocell fibers led to reduced growth and higher burrowing rates among earthworms.
Lead author Winnie Courtene-Jones, formerly a research fellow within the International Marine Litter Research Unit at the University of Plymouth and now a lecturer in marine pollution at Bangor University, emphasized the urgent need for further research.
“Over 320,000 tonnes of bio-based and biodegradable fibers were produced globally in 2022, and research shows that substantial quantities of that will end up in the environment. However, evidence of their ecological impacts has been lacking. Our study has shown that bio-based fibers have a range of adverse effects on earthworms – animals which are critical to the functioning of the environment,” Courtene-Jones said in a news release. “It highlights the importance of gathering further evidence before alternatives to conventional plastics are made available even more widely.”
This study underscores the complex nature of global efforts to combat microplastic pollution and highlights the necessity of thoroughly testing materials touted as eco-friendly alternatives before they penetrate markets worldwide.
The research arrives on the eve of a critical meeting of world leaders in Busan, South Korea, to discuss the prospective Global Plastics Treaty.
Senior author Richard Thompson, a professor of marine biology and director of the Marine Institute at the University of Plymouth, underscored the significance of the findings.
“There is increasing interest in alternative materials that could be used as substitutes for plastic, but this publication further emphasizes the importance of testing new innovations in relevant environmental settings prior to widescale adoption,” Thompson said in the news release. “I firmly believe it is possible to tackle the plastic pollution crisis, but independent scientific evidence will be critical in helping us avoid unintended consequences as we look for solutions.”
This study adds a new dimension to understanding the environmental impacts of materials designed to be more sustainable, urging caution in their adoption until more comprehensive research is completed.