Plastic fibres an increasing threat to marine environment, study shows

SYNTHETIC clothing could be a significant source of tiny pieces of plastic that are accumulating in the marine environment, a study shows.

Researchers found that a single garment cleaned in a domestic washing machine could produce more than 1900 fibres per wash, which could end up in sewage. Mark Browne, from the University of Sydney, said microplastic contamination posed a health threat to marine organisms and was likely to increase.

''To tackle this problem, designers of clothing and washing machines should consider the need to reduce the release of fibres into wastewater,'' said Dr Browne, from the Centre for Research on the Ecological Impacts of Coastal Cities.

His team tested sediments from sandy beaches at 18 sites around the world, including Port Douglas in Queensland and Busselton Beach in Western Australia.

Beaches in Japan, Oman, the Philippines, South Africa, Britain and the US were also sampled. The team found contamination with microplastic - fragments less than a millimetre in size - varied from eight fibres a litre of sediment in Australia to 124 fibres a litre in Portugal and Britain.

The more densely populated the area was, the more microplastic was present. Dr Browne said that apart from textiles, other possible sources of microplastic were the breakdown of large pieces of plastic, small plastic particles used as abrasives in cleaning products and spills of plastic powders and pellets.

To determine the main source of microplastic contamination on the beaches, Dr Browne's team tested sewage sludge disposal sites in Britain, as well as effluent from the sewage treatment plants at west Hornsby and Hornsby Heights in Sydney. They also washed synthetic clothes and blankets, finding that all garments released more than 100 fibres a litre of effluent.

The proportions of polyester and acrylic fibres in clothing were found to resemble those in effluent on the beaches and at sewage disposal sites. This suggested that the washing of clothes - rather than fragmentation or cleaning products - was the main source of the debris.