An experiment with worms has raised doubts about the eco-friendliness of biopolymer materials.

Researchers from the United Kingdom have compared the effects of three types of fibers on compost worms. The first fiber, polyester, is a synthetic polymer, while the other two—viscose and lyocell—are derived from cellulose and are generally considered more environmentally friendly. However, the experiments revealed that the toxicity of the latter two fibers to these essential soil inhabitants is even greater than that of the polyester fiber.

2024-11-06 10:01:07https://naked-science.ru/article/biology/eksperiment-s-chervyami

Semisynthetic textile fibers such as lyocell and viscose are increasingly being used for the production of clothing, wet wipes, and other products. These materials are often marketed as more natural and eco-friendly compared to polyester or polyethylene terephthalate, which are derived from petroleum products.

However, the reality is more complex: although cellulose is the raw material for both lyocell and viscose, their production involves chemical processes that negatively impact the environment. Additionally, during washing or simply through wear and tear, microfibers from these fabrics can enter wastewater, and subsequently, waterways and soil.

Despite the growing production and sales of biofiber products worldwide, the potential impact of such materials on the environment has been little studied. A recent contribution to this field came from a group of specialists in biological sciences and ecological sustainability from the University of Plymouth (UK). Their article was published in the journal Environmental Science and Technology.

For their experiment, they selected compost worms (Eisenia fetida), and this choice was not arbitrary. Due to their role in enriching soil and maintaining its health and fertility, they are sometimes referred to as "biological engineers." These worms help to rapidly decompose organic waste and fresh manure, turning it into biohumus — a completely natural fertilizer.

The researchers found that at high concentrations of polyester fibers in the soil, 30% of the worms died within 72 hours. In the case of lyocell, the mortality rate reached 60%, while with viscose, the fatality rate soared to 80%.

In a second experiment using ecologically significant concentrations of fibers in the soil, the worms that came into contact with viscose showed a more noticeable reduction in offspring compared to those exposed to polyester. In samples containing lyocell, the worms exhibited slightly slower growth and remained deeper in the soil longer than when interacting with the other two materials studied. This indicates that they found it more difficult to fulfill their ecological role.

The study's results demonstrated that the examined biofiber materials exhibit more pronounced acute toxicity at high concentrations and a generally similar sublethal effect on E. fetida, akin to that of polyester. This underscores the importance of testing alternative options proposed to replace plastic before their widespread adoption, concluded the authors of the article.

In a previous study involving the same researchers, it was shown that "eco-friendly" tea bags did not decompose in the soil and harmed Eisenia fetida worms just as much as standard plastic counterparts.