"What surprised us were the deleterious effects that natural fibers have on the digestion and immunity of the oyster," said Camille Détrée, lecturer in marine biology at the University of Caen-Normandy, quoted in a statement.
"The roughness of the surface of natural fibers is greater and likely causes stronger inflammation of the digestive walls during transit," she says.
The textile industry also uses up to 8,000 different chemical components to improve the properties of clothing, dyeing or pesticide treatment, questioning the supposed non-dangerousness of natural fibers, according to the authors.
Each year, about 2 million tons of microfibers, mainly of natural origin, are discharged into the oceans, largely through domestic washing machines, before being ingested by marine organisms, recalls this study conducted by scientists from Ifremer, the University of Western Brittany, CNRS and the University of Le Mans.
They exposed cupped oysters to natural (wool, organic or non-organic cotton) and synthetic (acrylic, nylon and polyester) textile microfibres and their chemical additives for 96 hours.
They then studied the ability of oysters to ingest these microfibers and compared the effects on their health.
A first experiment was carried out with a concentration of 10 microfibers per liter, considered as the average rate in the oceans, and a "catastrophic" scenario with a concentration of 10,000 microfibers per liter.
"We did not observe more effects on oysters exposed to high or low concentrations of microfibers. This suggests that a low environmental dose is sufficient to trigger effects on their health," says Ms. Détrée.
According to Arnaud Huvet, marine biologist at Ifremer and co-author, the study shows that microfibers of natural origin "do not seem to have any less impact than synthetic ones on the health of oysters". "It is nevertheless important to take into account their persistence period in the marine environment: a few weeks or months for 100% natural fibers, compared to tens or even hundreds of years for synthetic materials."
Rather than promoting natural fibers, the authors argue for the adoption of slow fashion extending the lifespan of clothing.
© 2023 AFP