Toxic Sportswear: The Hidden Chemical Dangers in Your Gym Gear
While many people embrace regular exercise for health benefits, the clothing worn during workouts might be undermining those efforts. Professor Mohamed Abdallah, a Professor of Environmental Chemistry and Toxicology at the University of Birmingham, avoids high-performance sportswear in favour of natural fabrics like cotton. This choice stems from over a decade of research into how chemicals interact with the human body, revealing that synthetic athletic wear could expose wearers to toxic substances.
The Permeability of Skin and Chemical Leaching
Contrary to long-held beliefs, human skin is more permeable than previously thought, especially during physical activity. Most modern sportswear is crafted from synthetic fibres such as Lycra and spandex, treated with chemical finishes including plasticisers, flame retardants, antimicrobial agents, chlorine bleach, and formaldehyde. Professor Abdallah explains that when we exercise, sweat can cause these chemicals to leach from the fabric, facilitating absorption through the skin and into the bloodstream.
To study this phenomenon, Abdallah developed a laboratory method using an engineered 3D human skin model, allowing his team to analyse chemical absorption without 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." His findings suggest the interaction between these fabrics and the body is dynamic and potentially hazardous.
Case Studies and Broader Health Concerns
The risks are not merely theoretical. Alden Wicker, author of To Dye For: How Toxic Fashion Is Making Us Sick, investigated the impact after airline staff reported unexplained illnesses. In 2011, Alaska Airlines introduced new synthetic uniforms, leading to symptoms like hair loss, burns, persistent coughs, and incapacitation among flight attendants. Testing identified chemicals such as dimethyl fumarate, an antifungal agent banned in the EU. Although legal action was unsuccessful, the airline later replaced the uniforms, and a 2018 Harvard study noted a doubling in health issues among attendants.
Wicker highlights that performance clothing often contains PFAS, or "forever chemicals," which are highly toxic and potentially carcinogenic. "Anything marketed as 'performance'—stretchy, sweat-wicking, stain or water-resistant—is usually achieved through chemical finishes," she warns.
Microplastics and Indoor Air Pollution
Professor Martin Wagner, an environmental toxicologist at the Norwegian University of Science and Technology, adds that synthetic fabrics shed microscopic fibres, contributing to indoor microplastic pollution. "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," he explains. In enclosed spaces like gyms, this can lead to significant inhalation exposure, compounding health risks.
Wagner's research indicates that around 16,000 chemicals are present in plastic products, with a quarter classified as hazardous. He suspects many of these are used in synthetic fibres, alongside engineered coatings like nano silver to control sweat odour.
Innovations and Alternatives in Sportswear
Despite these concerns, there are signs of progress. Designers and material scientists are exploring alternatives, such as biopolymers derived from natural sources, which reduce environmental impact and health risks. Charles Ross, a sportswear design specialist at the Royal College of Art, notes that the industry is transitioning away from forever chemicals. Innovations include enzyme-based dyeing, carbon dioxide dyeing, and plant-based alternatives to elastane.
However, Ross cautions that even natural fabrics like cotton undergo chemical processing during cleaning, dyeing, and finishing. "We've created materials that no longer readily decompose," he says, blurring the line between natural and synthetic. Harmful substances are pervasive in modern life, from cosmetics to contact lenses, though reducing exposure remains crucial.
Cultural Shifts and Future Directions
Exhibitions like Performance Without Toxicity at Mills Fabrica's Fabrica X gallery in North London showcase sustainable innovations, such as plastic-free fleece and elastic fibres from corn. Amy Tsang, Mills Fabrica's European head, emphasises the need for greater consumer awareness. "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. Revisiting natural fibres like linen, hemp, and tightly woven cotton, enhanced with modern science, offers promising solutions.
Wicker and Abdallah agree that while individual choices can reduce exposure, governmental action is essential. "This isn't a problem that can be solved by individuals alone," Wicker asserts. Abdallah adds that consumer demand will drive industry change toward safer materials. In the meantime, he encourages maintaining an active lifestyle while being mindful of fabric choices. "An active lifestyle is essential," he concludes. "It's simply about being more mindful of the fabrics we choose."
