January 29th, 2012 by University College Dublin
Microplastic, polyester and acrylic particles of less than one millimetre in size, released from synthetic fabrics during machine washing, is contaminating the world’s shorelines.
According to a study led by Dr Mark Anthony Browne now with the National Center for Ecological Analysis and Synthesis (NCEAS) in Santa Barbara, California, over 1,900 fibres can wash off a single piece of clothing during a machine wash cycle and end up on the shoreline.
The research published in the paper “Accumulation of Microplastic on Shorelines Worldwide: Sources and Sinks” in the US journal Environmental Science and Technology provides new insights into the origin of the microplastic and where it ends up.
The research showed that eighteen shores across six continents were contaminated with microplastic.
To investigate the main source of the microplastic contamination on the beaches, Dr Browne’s team examined sewage sludge disposal sites and effluent from sewage treatment plants.
They also washed synthetic clothes and blankets, and discovered that they released more than 100 fibres per 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, the researchers say, suggests that the washing of clothes – rather than the fragmentation of plastic waste or cleaning products – was the main source of the microplastic debris on the coastlines.
“We show polyester, acrylic, polypropylene, polyethylene, and polyamide fibres contaminate shores on a global scale, with more in densely populated areas and habitats that received sewage,” explained Dr Browne.
“As the human population grows and people use more synthetic textiles, contamination of habitats and animals by microplastic is likely to increase,” he said.
“Designers of clothing and washing machines should consider the need to reduce the release of fibres into wastewater.”
According to Dr Browne and the international team of scientists who conducted the study, work is urgently needed to determine if microplastic can transfer from the environment and accumulate in food-webs through ingestion.
“In humans, inhaled microplastic fibres are taken up by the lung tissues and can become associated with tumours, while dispersive dyes from polyester and acrylic fibres have been shown to cause dermatitis.”
The research was funded by Leverhulme Trust (UK), the Centre for Research on the Ecological Impacts of Coastal Cities at the University of Sydney, and Hornsby Shire Council, Australia.