November 11, 2024
Growing concern about plastic pollution has led to an increasingly common push to promote so-called bio-based materials as a greener alternative. But a new study published in Environmental Science and Technology suggests these materials could cause more environmental harm than conventional plastics. Researchers at the University of Plymouth and the University of Bath researched the effect of bio-based fibres, such as viscose and lyocell, on earthworms to highlight the ecological risks that maybe these materials need more extensive testing before they become popular.
Emerging Bio-Based Plastics: Alternatives to Plastics
Bio-based plastics, which come from renewable biological sources, are among those options that can mitigate the current plastic pollution problems. Used in everything from clothing to wet wipes and sanitary products that are used once and then discarded, over 320,000 tonnes were produced in 2022 worldwide, while most the works on these materials have yet to be considered in order to elucidate their environmental implications.
In contrast, one of the key routes of environmental pollution for bio-based fibers is through microfibers that are detached during washing procedures and can enter the water cycle and be deposited in soil communities due to sewage sludge having become an acceptable fertilizer. Another source of microfiber release into the environment arises from the wear and tear of textile products.
This report addressed the need for knowledge of the potential impacts of bio-based fibres on the environment, and it indicates the risks that may manifest when alternatives to conventional plastics are applied in use without comprehensive testing.
Study Findings: Bio-Based Fibres and Earthworm Mortality
Scientists targeted earthworms, which is the organism critical for soil health. The Earthworms improve soil quality by making nutrients mobile and improving circulation in the soil, so any challenge to their wellbeing could affect ecosystems significantly. Two experiments were designed to compare, side by side, a common petro-based polyester fiber with two new bio-based fibers, namely: viscose and lyocell.
In a high-concentration exposure experiment, earthworm mortality varied with the fibre type. In the case of earthworms exposed to polyester fibres, mortality took place within 72 h at 30% mortality, while for those exposed to lyocell and viscose, mortality was significantly higher at 60% and 80%, respectively. These results suggest that bio-based materials are not as harmless as was once believed and might in fact present greater risks for some species.
Impact of Bio-Based Fibres on the Reproductive Growth of Earthworms
The authors undertook a second test, employing concentrations of fibres that were more likely to occur in natural habitats to determine the long-term impacts. This test phase showed that exposed viscose fibres earthworms had reduced reproductive rates, while lyocell-exposed earthworms grew at a lower rate. Lastly, the soils exposed to lyocell contained the earthworms burrowing, which was more active than the controls. This could be an attempt to hibernate or escape undesirable conditions in the earthworm’s habitat.
Thus, this reveals complex biological responses to such bio-based fibers, which may likely have implications in soil ecosystems since they are related to earthworm activity. According to researchers, the impact of bio-based materials is variable, posing a challenge to the balance of the ecosystem and biodiversity.
Bio-Based Fibres: The Dangers of Premature Adoption
Lead author on this paper, Dr. Winnie Courtene-Jones says: “The overuse of bio-based materials without adequate research on the impact on the environment may have some unintended consequences. Earthworms are, for example an important constituent in the maintenance of healthy soils. These fibres may likely end up accumulating in natural habitats, causing problems there if not studied well enough.”.
While touted as ‘eco-friendly’, said Dr. Courtene-Jones, bio-based fibres revealed a spectrum of potential adverse effects on earthworms from the research of this paper. It is absolutely critical to consider these impacts in this shift of consumer products replacing original petro-based alternatives with their bio-based versions before it becomes such a deeply ingrained paradigm that the mistakes of conventional plastics are repeated.
Implications for Global Plastics Policy and the Road Ahead
Conveniently, the research coincides with just weeks before world leaders meet to negotiate the last stretch of a possible Global Plastics Treaty, which will be held in Busan, South Korea. The treaty proposes to streamline a worldwide approach on reducing plastic pollution by establishing an international framework. The findings in the study are likely to shape the policymakers’ opinion about alternative materials.
He further stated that plastic usage had to be minimized through recycling, reuse, and scientifically evaluated substitutes. In welcoming bio-based plastics as such an alternative, he also again and again emphasized the need for scientific backup evidence in such a transition to avoid a potential fist to the ecosystem. Professor Richard Thompson OBE FRS, the senior author of the research and Head of the University of Plymouth’s International Marine Litter Research Unit, will take part in these discussions.
Scientific Evidence towards Sustainable Solution
In this research, companies, governments and consumers are urged to take a step towards sustainability when making choices on alternative plastics through evidence in data. It holds the opinion that though solutions towards the plastic crisis may be found, independent studies and environmental testing need to be brought into place. The manufacturers and policymakers need to be sure that the alternative materials are nontoxic as alternatives for the conventional plastics in ecosystems.
The Natural Environmental Research Council has provided £2.6 million for the BIO-PLASTIC-RISK project in a bigger attempt to mitigate against the risk of ecological impacts generated from biodegradable and bio-based plastics. This work feeds into an increasingly large body of evidence that suggests that bio-based materials, although not harmful in their own right, perhaps are more damaging than anticipated to species that interact directly with soils containing these fibres.
Conclusion
This paper is a wake-up call for industries and policymakers pushing for bio-based materials as alternatives to plastic. The evidence here indicates that bio-based fibres have complex and sometimes harmful effects on key species, such as earthworms in soil health and balance. This kind of research will be necessary for world leaders as they seek effective solutions to plastic pollution, giving critical insight into the urgency with which alternative materials must be tested before being broadly introduced.
The next big negotiation platform comes at the United Nations Global Plastics Treaty in Busan and is a good opportunity to share these results and advance frameworks that take precedence and enhance safety and sustainability for the environment. Independent scientific research would be very much needed in seeking alternatives to plastics so that new materials contribute to ecological preservation, rather than introducing new risks.
Source: Environmental Science and Technology, University of Plymouth, University of Bath