Study identifies adverse impact of bio-based materials on earthworms

Bio-based materials - which are used in textiles and products including clothing, wet wipes and period products - emit microfibres into the environment through the laundry cycle, the application of sewage sludge as fertilisers, or through wear and tear of textile products.

Despite increasing quantities of bio-based products being produced and sold globally, there has been little research to assess their potential impact on species and ecosystems.

Now, a study detailed in Environmental Science and Technology tested the effects of conventional polyester fibres and two bio-based fibres – viscose and lyocell – on earthworms, an important invertebrate that eats decaying plant material and creates healthy soils.

The study found that in high concentrations of fibres, 30 per cent of earthworms died after 72 hours when exposed to polyester, while those exposed to the bio-based fibres experienced mortality of up to 60 per cent for lyocell and 80 per cent for viscose.

A second experiment, using environmentally relevant concentrations of the fibres, indicated that earthworms housed in soils containing viscose fibres exhibited reduced reproduction compared to those exposed to polyester fibres. Earthworms in the soils containing lyocell fibres showed reduced growth and higher rates of burrowing within the soil compared to exposure to the other types of fibre.