Are your clothes fish-friendly? Fabrics that are cut using scissors shed up to 31 times more microplastic fibres into the ocean than those cut with lasers, study finds
- Clothes manufactured with scissors more easily detach loose fibres into waters
- Higher quantities of fibres also originate from processed surfaces and cut edges
- These fibres detach in the washing machine and eventually can enter the ocean
Clothing is more prone to shredding microscopic plastic fibres into our waterways if it has been manufactured using scissors, a new study reveals.
In experiments, scissor-cut textiles shed up to 31 times more micro-fibres than laser-cut textiles, Swiss researchers found.
When clothes are washed, or items are discarded as litter, tiny fibres are released and these often flow into water sources and out to sea.
Microplastic pollution is ubiquitous in the marine environment and is ingested by numerous marine species, including sharks and turtles.
Scientists suggest changes to clothes production, including more laser-based manufacturing processes, could help reduce the amount of microfibers that reach the sea.
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Stray fibres extracted from four types of textiles: A) interlock S; B) plain F; C) fleece and D) microfiber, which is a common material made from ultra-fine synthetic yarns
Lasers result in cleaner cuts at the microscale compared to scissor cuts, which are result in fabrics that are more frayed at the edges and shed fibres during washing.
‘Our results confirm the presence of microplastic fibres in textiles throughout the manufacturing process,’ said Yaping Cai and colleagues at the Swiss Federal Laboratories for Materials Science and Technology in Dübendorf, Switzerland.
‘The results of this study may help to reduce the microplastic fibre release from textiles by modifications throughout the production and finishing process.’
Microplastics, small pieces of plastic and fibres less than five millimetres in length, can come from plastic bottles, packaging, cosmetics and micro-beads in toiletries.
Less known about are microfibres, from textiles and clothing, which are also small enough to pass through the filter systems in domestic waste water treatment plants.
The tiny plastic fibres, thinner than a human hair, are eaten by plankton and shellfish when they reach the ocean and can ultimately be consumed by humans.
The increasing global production of synthetic textiles raises the concern that the microfibres are likely to continue contaminating our environment, the researchers predict.
SEM images shown for three textile samples: A) interlock; B) twill; and C) and D), plain brushed
LASER CUT FABRICS
Laser cut fabrics are used throughout the textile industry.
Laser beams are used to cut edges more cleanly and thereby prevent fraying.
Laser cutting is a totally contactless process and nothing but the laser beam itself touches the fabric, minimising the chance of fraying or distortion.
Laser cutting can be used on a range of materials, from cotton, linen, lace, polyester and fleece.
But it had been unclear to what extent the microfibres originate from processes during washing, such as abrasion.
To learn more, the researchers used a sonication method to extract the microfibres from a variety of textiles.
The technique of sonication involves the application of sound energy to agitate particles in a certain sample, to simulate a washing machine.
The edges of the laser- and scissor-cut samples were then analysed with a scanning electron microscope (SEM).
Overall, scissor-cut textiles demonstrated somewhere between three to 31 times higher number of extracted microfibres than laser-cut textiles.
The majority of the extracted microfibres were found to be between 100 and 800 micrometres (one millionth of a metre) in length.
On average, five times more microfibres could be extracted from textiles with ‘processed’ surfaces, such as fleece, ‘brushed’ material and microfiber – a common material made from ultra-fine synthetic yarns – compared to those with unprocessed surfaces, they found.
Surface treatment is a later stage in clothes production, when sprays and other finishing chemicals are applied to improve the material’s feel or appearance.
When clothes are washed, or items are discarded as litter, tiny fibres are released and these often flow into water sources and out to sea
Laser cutting fabrics
The highest number of extracted microfibres was found for the microfiber textile, with 45,400 microfibres per gram and 11,300 microfibres per gram for the scissor-cut and laser-cut samples, respectively.
These figures were approximately 60 times higher than the number of microfibres extracted from twill, a weave pattern that has diagonal lines on the face of the fabric.
Twill exhibited the lowest number of extracted microfibres – 760 microfibres per gram for scissor-cut and just 120 microfibres per gram for laser-cut samples.
But the team suggest that abrasive friction during the production process may be a critical factor for microfibre formation.
Rotor spinning and surface treatment are among the most critical steps responsible for the formation of loose microfibres during the yarn production and textile production, respectively.
Rotor-spun yarns, made by twisting of rotor by a rotor spinning machine, released 4,310 microfibres per gram – much higher than other types of yarns, which ranged from 160 to 230 microfibres per gram.
This suggests the rotor spinning approach may be a critical step responsible for the formation of microfibres before the enter the water system.
The research team suggest the need for a more representative study on rotor-processed yarns.
Industry scrutiny of the cutting and seaming processes will also offer a way to minimise microfibres release from garments.
‘One of the most important findings in our study is that the amount of microplastic fibres extracted from textiles was significantly influenced by the cutting method,’ the team say.
‘From the SEM images, we know that the textile edges of laser-cut samples exhibited a seal of molten polymer and the scissor-cut samples consisted of a large number of open ends near the edge.
‘Therefore, the major source of microplastic fibres from laser-cut samples is the surface and for the scissor cut ones the source is both the surface and the edges.’
The study has been published in Journal of Cleaner Production.
WHAT CAN MICROPLASTICS DO TO THE HUMAN BODY IF THEY END UP IN OUR FOOD SUPPLY?
According to an article published in the International Journal of Environmental Research and Public Health, our understanding of the potential human health effects from exposure to microplastics ‘constitutes major knowledge gaps.’
Humans can be exposed to plastic particles via consumption of seafood and terrestrial food products, drinking water and via the air.
However, the level of human exposure, chronic toxic effect concentrations and underlying mechanisms by which microplastics elicit effects are still not well understood enough in order to make a full assessment of the risks to humans.
According to Rachel Adams, a senior lecturer in Biomedical Science at Cardiff Metropolitan University, ingesting microplastics could cause a number of potentially harmful effects, such as:
- Inflammation: when inflammation occurs, the body’s white blood cells and the substances they produce protect us from infection. This normally protective immune system can cause damage to tissues.
- An immune response to anything recognised as ‘foreign’ to the body: immune responses such as these can cause damage to the body.
- Becoming carriers for other toxins that enter the body: microplastics generally repel water and will bind to toxins that don’t dissolve, so microplastics can bind to compounds containing toxic metals such as mercury, and organic pollutants such as some pesticides and chemicals called dioxins, which are known to causes cancer, as well as reproductive and developmental problems. If these microplastics enter the body, toxins can accumulate in fatty tissues.
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