Like many of us, Professor Mohamed Abdallah likes to take regular exercise.
But it is what he chooses to wear while doing it, however, that deviates from the norm. The Professor of Environmental Chemistry and Toxicology at the University of Birmingham steers clear of specialist workout gear, instead sticking to natural fabrics like cotton.
This isn’t a stylistic choice, but one shaped by more than a decade spent researching how chemicals interact with the human body, which found that while high-performance sportswear may look the part, it could be exposing us to toxic substances.
Lycra, spandex and waterproof membranes have helped transform the way we exercise, and it’s a fair bet that, unlike Professor Abdallah, most of us would be reluctant to swap our supportive sports bra or lightweight running top for heavy, sweat-soaked cotton.
Yet a growing body of research suggests that we’d all be better off following in his footsteps – and that the clothes we wear to help get fitter might actually be working against us.
Not least because, while long thought of as an effective barrier, human skin is now understood to be more permeable than we once believed.
And as most sportswear is made from synthetic fibres and treated with a cocktail of chemical finishes – among them plasticisers, flame retardants, antimicrobial agents, chlorine bleach and formaldehyde – this is not great news for gym bunnies.
‘When I started this research ten years ago, most of the focus was on what we eat, drink and breathe,’ Professor Abdallah explains. ‘There was very little attention on what we wear, what we touch, and what comes into contact with our skin.’
To explore this, Abdallah developed a laboratory method using an engineered 3D human skin model, allowing his team to study chemical absorption without relying on animal or human testing.
‘A lot of modern fabrics are made from polymer materials designed to deliver specific properties – stretch, water resistance, sweat-wicking,’ he says. ‘But to achieve these, manufacturers add chemicals such as plasticisers, flame retardants and water-repellent compounds.’
What his research suggests is that the interaction between these fabrics and the body is more dynamic than we might assume.
‘Skin is a highly sophisticated tissue,’ he says, ‘but when you work out, sweat can cause chemicals to leach out of the fabric. That sweat then facilitates their absorption through the skin and into the bloodstream.’
The implications are still being understood – long-term studies on clothing-specific exposure are still limited – but the potential risks are concerning enough for Professor Abdallah to avoid such fabrics himself wherever possible.
He is not alone in his concerns. Alden Wicker, author of To Dye For: How Toxic Fashion Is Making Us Sick, began investigating the impact of our clothing on our health after a spate of unexplained illnesses among airline staff.
In 2011, flight attendants working for Alaska Airlines reported a troubling range of symptoms following the introduction of new high-performance synthetic uniforms. ‘They were losing hair, experiencing burns and persistent coughs, and in some cases were completely incapacitated when they got on the plane,’ Alden recalls.
Subsequent testing identified a range of chemicals in the uniforms, including dimethyl fumarate, an antifungal agent that had recently been banned in the European Union.
Although legal action against the manufacturer ultimately came to nothing, Alaska Airlines later replaced its uniforms without formally acknowledging a link to staff complaints.
Nonetheless, a 2018 Harvard study found that after the introduction of the uniforms in 2011, the number of attendants with multiple chemical sensitivity, sore throats, cough, shortness of breath, itchy skin, rashes and hives, itchy eyes, loss of voice, and blurred vision had all more or less doubled.
Despite the headlines the case generated at the time, Wicker believes the broader issue of chemicals in our clothing has remained largely under the radar.
‘Anything marketed as “performance” – stretchy, sweat-wicking, stain or water-resistant – is usually achieved through chemical finishes,’ says Wicker. ‘That often means the presence of PFAS, or forever chemicals, which are highly toxic and potentially carcinogenic.’
Neither is it just our stretchy leggings that are the problem, as Professor Martin Wagner, an environmental toxicologist at the Norwegian University of Science and Technology explains.
For more than 20 years, his research has focused on plastics and their impact on both ecosystems and human health. Among his studies is one showing that there are an astonishing 16,000 chemicals known to be present in plastic products, around a quarter of them classed as hazardous.
‘I am not a textile expert, but I would assume that some of these 16,000 chemicals will also be used in synthetic fibres – and then of course you get a whole lot of other engineered coatings, that are sometimes added on, like nano silver to suppress the smell of sweat,’ he says.
And it’s not just our clothes we should be worrying about, as from a toxicological perspective, inhalation and ingestion are still currently thought to be the primary routes of human exposure to chemicals.
‘Synthetic fabrics also shed microscopic fibres – a form of microplastic – which accumulate in the air around us,’ Wagner explains.
‘If you do your yoga on a plastic mat, you will inhale microplastics – and it’s not just mats. It’s clothing, carpets, furniture – all releasing fibres into indoor air which in an enclosed space like a gym can mean there’s a lot of them and that’s what you’re breathing most of the time.’
There are signs that change may be coming. Designers and material scientists are increasingly exploring alternatives to conventional synthetics, including biopolymers derived from natural sources.
Charles Ross, a sportswear design specialist at the Royal College of Art, describes the field as being in a period of transition.
‘Historically, performance fabrics were made using a lot of forever chemicals,’ he says. ‘Now there is much better practice emerging.’
Biopolymers – materials derived from renewable biological sources rather than fossil fuels – are one promising avenue. While not entirely free from chemical processing, they can reduce both environmental impact and potential health risks for both the planet and its residents.
Other new techniques such as enzyme-based dyeing and carbon dioxide dyeing are also reducing the need for water and harsh chemicals, while other companies are developing plant-based alternatives to elastane and fabrics that mimic the performance of synthetics without relying on petrochemicals.
All that said, Ross points out that even so-called natural fabrics are not always as pure as they appear.
‘By the time you’ve grown cotton, cleaned it, dyed it and finished it, you’ve still introduced a lot of chemistry,’ he says. ‘We’ve created materials that no longer readily decompose.’
In other words, the distinction between ‘natural’ and ‘synthetic’ is not always clear-cut. ‘And harmful substances are not confined to clothing,’ Ross continues.
‘They are present across many aspects of modern life, from cosmetics to contact lenses. The human body is not defenceless – but at the same time, that doesn’t mean we shouldn’t try to reduce exposure where we can.’
In North London meanwhile, the Performance Without Toxicity exhibition, hosted in its Fabrica X gallery by Mills Fabrica, a company working in the field of sustainability in the world of textiles and agriculture gallery space, is showcasing ways we may do this in future.
Among the pieces on show are plastic-free fleece fabrics designed to replicate the feel of nylon, and clothing made with elastic fibres derived from corn rather than oil.
‘There’s a huge amount of work being done,’ says Mills Fabrica’s European head Amy Tsang. ‘And there are already products out there if people want to find them.’
For Tsang, the challenge of highlighting the issues with synthetic activewear is partly cultural: consumers may have become accustomed to scrutinising what they eat and the ingredients in their beauty products, but clothing has largely escaped the same level of attention.
‘We’re not thinking about the fact that our skin is our largest organ, and what we put on it every day matters,’ she says.
Tsang believes some of the most promising ideas involve looking backwards as well as forwards – revisiting natural fibres such as linen, hemp and tightly woven cotton, which have been used for centuries, while applying modern science to enhance their performance.
Wicker agrees, although she points out that the individual can only do so much.
‘You can reduce your own chemical exposure through the choices you make about what you wear and buy,’ she says. ‘But governments should be doing far more to protect us – this isn’t a problem that can be solved by individuals alone.’
It’s a sentiment that chimes with Professor Abdallah, who also believes that in large part change will depend on consumer demand.
‘Otherwise there is little incentive for industry to act,’ he says. ‘But once the public demands safer alternatives, that will drive development of better materials.’
In the meantime, he hopes none of us will be put off our gym-focused stride. ‘An active lifestyle is essential,’ he says. ‘It’s simply about being more mindful of the fabrics we choose.’
