Recent findings from a study conducted by researchers at the University of Plymouth and the University of Bath indicate that biodegradable fibers may pose a greater health risk to essential species than conventional plastics they aim to replace. This research, part of the BIO-PLASTIC-RISK project, was published in the journal Environmental Science and Technology on November 5, 2024.
The study examined the effects of conventional polyester fibers and two biodegradable fibers, viscose and lyocell, on earthworms—crucial organisms for global soil health. In high concentrations, the study revealed that 30% of earthworms exposed to polyester died within 72 hours. In stark contrast, exposure to biodegradable fibers resulted in much higher mortality rates, with up to 60% for lyocell and 80% for viscose.
Further experiments using environmentally relevant fiber concentrations demonstrated that earthworms in soils containing viscose fibers experienced reduced reproduction rates. Those exposed to lyocell fibers exhibited stunted growth and increased burrowing activity compared to those in polyester environments.
Dr. Winnie Courtene-Jones, the lead author and now a professor of marine pollution at Bangor University, emphasized the significance of these findings. "In 2022, over 320,000 tons of biodegradable fibers were produced globally, and substantial amounts are likely to enter the environment. However, there is a lack of evidence regarding their ecological impacts. Our study highlights several adverse effects on earthworms, which are vital for ecosystem functioning. It underscores the need for more research before these alternatives to conventional plastics are widely adopted," she stated.
This study follows earlier research published in early 2024, which noted that biodegradable tea bag materials could increase earthworm mortality by up to 15% and adversely affect their reproduction. The timing of these findings is critical, as global leaders prepare to meet in Busan, South Korea, for final negotiations on a potential Global Plastics Treaty.