Plastic fibres time bomb in laundry effluent

In the March 2019 issue of LCNi, we raised the growing problem of microfibres in laundry effluent. This month we review the progress which has been made in the intervening four years, summarising some of the knowledge which universities worldwide have published and offering a current appraisal of the serious problems that have been identified.

Solids discharge in laundry effluent have rarely posed a problem up until now, and the cost is only a small component of the trade effluent treatment cost in most regions. This might be set to change. David Attenborough’s popular ‘Blue Planet’ programmes for the BBC and a host of similar series worldwide have highlighted the real and potential problems of plastics contamination of the oceans, including alarming data on the level of polyester microfibres found. This has now caught the attention not only of scientists but also of regulatory bodies, and national and state governments. This month we look at the research work which is revealing a potentially very serious worldwide problem, and which is apparently not being addressed in any urgent way, even by national governments.

Action taken so far

In early 2020, France became, we believe, the first country to legislate1 to reduce the discharge into rivers and oceans of microplastics, including both particles and microfibres. LCN understands that from 2025 in France, all new washing machines will have to incorporate a filter to stop synthetic textiles from polluting waterways1. The underlying work for this included assessment of a range of filters to confirm that this was both achievable and affordable. Interestingly, it is understood that the traxemarked XFiltra, developed by Xeros2 in Rotherham, UK proved to be the top performer and could now be made available as original equipment to any maker.

The only other state action to partially address the build-up of microplastics in our oceans is by California, which now has legislation requiring all new textile items containing polyester fibre to state the percentage of polyester it contains. This is presumably designed to flag up to purchasers the risk of this causing microfibre pollution in the wastewater from laundering, but it is thought unlikely to achieve anything like the imminent improvements to be expected in France.

The latest research results in a nutshell

In November 2020 the German University of Bayreuth3 found that plastic particles could acquire a surface coating of living biofilm, which acted like a ‘Trojan horse’ to aid their intrusion into the human body, to enter both tissue and organs.

By March 2021 , workers at the New Jersey Institute of Technology, USA4 had found that microplastics in wastewater could act as ‘hubs’ for antibiotic resistant bacteria. They likened the biofilm on the plastic surface to a ‘marketplace for superbugs to grow and exchange drug resistant genes’. Trials using water from three different treatment plants indicated that microplastics could bypass the standard municipal water purification processes.

In April 2021, researchers at Florida State University, USA5, reported the effect when microplastic particles entered human lung cells, changing their shape and slowing their metabolism. They were also found to cause aneurisms in fish and to stunt the growth of plants. This was against a background of work by the UN’s World Health Organisation, which had earlier reported finding microplastics in over 90% of bottled water samples.

In 2021, Nick Lavars of New Atlas published on Facebook a reference to work in Korea6 in which a mouse study showed that microplastics could infiltrate the blood brain barrier, where they were found to act as toxic substances. They built up in the microglial cells (which are key to maintenance of the central nervous system) and impacted on their ability to proliferate.

In December of the same year, another Facebook post by Nick Lavars of New Atlas reported work by Hull York Medical School in the UK7, which suggested that microplastic particles can cause damage to brain cells. It also noted that microplastic particles were now being found in human stool samples.

 In March 2022, another Facebook post by Nick Lavars of New Atlas reported work in the Netherlands8 which found microplastic particles in the human bloodstream for what is believed to be the first time. The concentration was described as ‘a teaspoonful in every 1000 litres of blood’.

In September 2022, a reference was made, in another Facebook post by Nick Lavars of New Atlas, to a study showing microplastics, 80 nanometres across, disrupting the metabolism of human lung and liver cells9.

This growing body of evidence could have serious implications for the textile rental sector, which can be minimised if the necessary solutions are identified now. Fortunately, much work is in hand to facilitate these and this month we look again at some of the probable implications for textile purchase and rental laundering.

What exactly is the problem?

The majority of rental textiles contain plastic fibres, especially polyester. These tend to be much more brittle than cotton, so tiny fragments of plastic are released in wear and in laundering. Tiny pieces of cotton are released as well, but these are considered biodegradable because they decompose over a few years, unlike polyester, which can survive for hundreds of years. It is polyester which forms a significant portion of the ‘plastic soup’ which is steadily developing in all of our oceans (although it is by no means the only constituent or even the major one).

What are the implications for textile rental?

Although the top end of the restaurant and hotel market demands pure cotton for its handle and breathability, the majority of the high volume market demands either cotton-rich or 50:50 polycotton. There has been some research into modifications to textile manufacture and processing operations, in order to reduce discharge of microplastic particles and fibre parts to drain (see for example www. oceancleanwash.org). However, it seems unlikely and unnecessary to expect this work to lead to a complete solution to the continuing discharge of these hazardous particles into the oceans.

What is needed, both domestically and for the commercial launderer, is a simple and inexpensive method of removing microplastics from wash liquors as these are being discharged to drain.

What is the likely solution?

The most cost-effective solution is likely to be filtration of all drain liquors as they exit the washing machine. The efficiency and cost-effectiveness of the Xeros design will probably be a trailblazer, both for the domestic market and for commercial machines. The clincher will probably be the percentage of the fibres it is claimed to remove. Although removing 99% of microplastics might look outstanding, the 1% of particles not removed still represents thousands of tons of plastic contaminating the seas.

Is there a way of accelerating the biodegradability of polyester?

There have been techniques published for increasing significantly the speed at which a plastic degrades, the most notable of which is probably the method for reducing PET to its original monomers. However, polyester is still proving very obstinate! Even if a method were to be devised, it is unlikely to be as cost-effective as filtration, which can now be achieved with a simple filter which only needs clearing once a week or so. Even as a means of addressing the elimination of the plastic particles already in our oceans, improved degradation is of uncertain viability. Accelerating the decomposition of any plastic would require careful attention to the by-products and the long-term effects of these on the environment.

What is the likely way forward for textile rental?

The present research indicates that polyester microfibres are building up steadily in the oceans worldwide, even at the greatest depths, year on year. There is a growing realisation that nations will need to tackle this ‘plastic soup’ sooner rather than later, to avert a problem that might yet be a serious as that of global warming. However, the world’s leading nations have much more pressing problems in their sights and there seems little likelihood that microfibres will trigger political action fast enough to achieve a low-cost solution. This might change if serious consequences are identified as the concentration of microfibres in the food chain continues to increase unchecked.

The prospect of developing a polyester fibre that does not break and shed millions of tiny particles is not remote, but it is unlikely. What is much more probable is that cotton-rich textiles will be developed which shed fewer particles (perhaps with modifications to fibre recipe and extrusion, combined with a suitable textile finish). With slight modifications in wash chemistry, this might reduce the discharge by perhaps 50%, but the basic problem will still be there. One solution could rely on another change in the main fabrics for textile rental, away from cotton-rich and 50:50 polycotton. This might be to another new cotton-rich fabric, or it might call for reversion to 100% cotton. Another solution could be the successful scaling up of the domestic laundry filter by Xeros, which is believed already to be well advanced.

If any change were to be mandatory, it would not affect the competitive position of a company in the marketplace, because everyone would have to comply. Before this happened, there would first be a major disruption in the domestic marketplace, because of the size of its contribution, which should give textile rental adequate time to respond.

Conclusion

Readers could well be amazed at the scientific revelations now emerging and wondering how we could have let this happen. Why has no-one acted yet and why are so few acting now? If France can take a lead and ensure that every washer sold in France from 2025 must be fitted with a suitable filter, why are others so sluggish to follow? The prize – cleaner oceans and healthier humans – lies within our grasp and is clearly affordable!