Switching to a cooler, faster laundry wash and higher-efficiency washing machines could save tonnes of microfibres being released into marine ecosystems in Europe, a new study as found.

Researchers from Northumbria University have been working with Procter and Gamble on the first major forensic study of real-life soiled laundry. Published in the scientific journal Plos One, it reveals that almost 13,000 tonnes of microfibres are being released into European marine environments every year.

Their forensic analysis revealed an average of 114 mg of microfibres were released per kilogram of fabric in each wash load during a standard washing cycle.

Given that a 2013 AISE (Association for Soaps, Detergents and Maintenance Products) report suggested 35.6bn wash loads are completed in 23 European countries each year, the researchers suggest 12,709 tonnes of microfibres are being released from washing machines into rivers, the sea, and the ocean each year in Europe alone.

However, the researchers achieved a 30% reduction in the amount of microfibres released when they performed a 30-minute 15°C wash cycle, in comparison to a standard 85-minute 40°C cycle, based on typical domestic laundering.

"If households changed to cooler, faster washes, they would potentially save 3,813 tonnes of microfibres being released into marine ecosystems in Europe," the researchers say.

They found even more significant differences when they compared different microfibre release from different types of North American washing machines.

Households in North America and Canada have historically used high volume traditional top-loading washing machines with an average 64 litre wash water volume. The market is gradually moving to high-efficiency machines which use up to 50% less water and energy per load.

As a consequence, these high-efficiency machines released less microfibres than traditional top-loading machines, with notable examples including a 70% reduction in microfibres from polyester fleece fabrics and a 37% reduction from polyester T-shirts.

The researchers also found that larger wash loads led to a decrease in the release of microfibres, due to a lower ratio of water to fabric, and new clothes release more microfibres than older clothes. Fabric softeners were also found to have no direct impact on microfibre release when tested in both European and North American washing conditions.

On a positive note, natural fibres from plant and animal sources biodegrade much more rapidly than synthetic fibres. A previous study has identified that cotton fibres degraded by 76% after almost eight months in wastewater, compared to just 4% deterioration in polyester fibres. This means that natural fibres will continue to degrade over time, whereas petroleum-based microfibres plateaued and can be expected to remain in aquatic environments for a much longer period.

"This is the first major study to examine real household wash loads and the reality of fibre release," says John Dean, professor of analytical and environmental sciences at Northumbria University, who led the study. "We were surprised not only by the sheer quantity of fibres coming from these domestic wash loads, but also to see that the composition of microfibres coming out of the washing machine does not match the composition of clothing going into the machine, due to the way fabrics are constructed.

"Finding an ultimate solution to the pollution of marine ecosystems by microfibres released during laundering will likely require significant interventions in both textiles manufacturing processes and washing machine appliance design."

The researchers say the study provides evidence for appliance manufacturers to introduce filtering systems into the design of machines and develop approaches to reduce water consumption in laundry. They also hope it will encourage textile manufacturers to help by conducting filtered pre-washing to remove the most labile fibres which can easily break down and displace.