Most people don't realize that your wardrobe is constantly acquiring, storing, and releasing substances. The paper, which reviews decades of research on clothing-mediated exposures, reveals that clothing acts simultaneously as a barrier, a filter, and a reservoir of potentially harmful substances.

From the moment you buy an article of clothing, it begins its chemical journey. New garments contain residues from manufacturing processes including dyeing, bleaching, and chemical finishing. But that's just the beginning.

What's Already in Your Clothes

When you purchase new clothing, you may be bringing home a cocktail of chemicals. Research has identified trace elements such as heavy metals, aromatic amines associated with certain dyes, benzothiazoles, dioxins, flame retardants, fluorinated surfactants, phthalate plasticizers, and formaldehyde from antiwrinkle resins. Even petrochemical constituents have been detected in new garments.

Some of these substances persist for years. For instance, polychlorinated dibenzo-p-dioxins (PCDD/F)—a group of highly toxic chemicals—were found in newly purchased textiles and demonstrated the ability to penetrate multiple layers of human skin.

The Sweat Factor: When Exercise Becomes Exposure

Sweating during exercise creates a unique chemical environment. Researchers have studied how artificial sweat extracts substances from clothing, including textile dyes and trace elements. The concern centers on the possibility that sweat could become a vehicle for transferring chemicals from fabric to skin during physical activity.

However, the actual transfer rates are notably lower than laboratory predictions might suggest. One study examined how much fluorescent dye transferred to volunteers during 30 minutes of exercise or 12 hours of normal activity while wearing treated garments—and found that less than 1% of the estimated amount actually transferred to their skin under these conditions.

The Dual Role of Clothing

What's particularly fascinating is that clothing plays a contradictory role in your exposure profile. Clean, uncontaminated clothing can actually protect your skin by reducing dermal uptake of airborne chemicals by factors of 3 to 6. However, clothing that has been previously exposed to contaminated air can do the opposite—amplifying your exposure to those same airborne chemicals by similar factors once you put it on.

This dynamic relationship means your clothing's history matters enormously. Garments stored in closets, transported through polluted environments, or worn in contaminated settings become "loaded" with those contaminants, which then transfer to your skin.

Beyond Chemicals: The Particle Problem

Clothing doesn't just harbor chemicals. It accumulates particles—both biological and abiotic. Research shows that allergens like cat and dog dander become trapped in clothing fibers and can be resuspended into your breathing zone during physical movement. School-based studies demonstrated that children unknowingly transport allergens from their homes to school on their clothing, then bring different allergens home.

Similarly, the research documents concerns about pathogenic bacteria on healthcare workers' clothing, including methicillin-resistant Staphylococcus aureus (MRSA). Even respiratory syncytial virus has been detected on clothing worn by healthcare providers.

Fabric Matters

The type of fabric significantly influences chemical and particle behavior. Polyester and wool each present different challenges. Wool, for instance, releases particles at rates up to 10 times higher than cotton or polyester. Tightly-woven fabrics offer better protection against particle emission, while loose weaves allow greater release of biotic particles.

Synthetic fabrics have different chemical partitioning properties than natural fibers, meaning they accumulate and retain certain contaminants differently. This is particularly relevant as global demand for synthetic fabrics continues to increase.

What Happens During Laundering

Washing removes some chemicals but can introduce others. Dry-cleaning leaves solvent residues on clothing. Detergents may deposit their own chemicals, including scents and surfactants. Some chemicals bond so tightly to fibers that they survive multiple wash cycles. Others, like certain dyes, partially remain even after washing.

Interestingly, adding bleach to laundry effectively eliminates bacteria but may increase the abundance of chlorinated organic compounds on clothing—creating a different potential exposure.

The Microplastic Problem No One's Talking About

Every time you wear, wash, or exercise in synthetic leggings, you're contributing to a growing environmental crisis that deserves far more attention than it gets. Most leggings are made from polyester and nylon—petroleum-based plastics that shed microscopic fibers called microplastics with every wear and wash.

Think about it: when you work out in leggings, friction causes these synthetic fibers to break down and shed. Washing them releases thousands of microplastic particles into our water systems. These tiny fragments end up in our oceans, soil, and eventually in the animals we eat. Even more concerning, microplastics have been found in human blood and organs, raising serious questions about long-term health impacts we're only beginning to understand.

The issue is so widespread that researchers now consider microplastic pollution one of the most pressing environmental challenges of our time—and your athletic wear is a major culprit.

Following the Money: Who Profits From Synthetic Fabrics?

Here's what many people don't realize: the oil industry has a vested interest in keeping us buying synthetic clothing. Major petrochemical corporations have massive investments in the production of polyester and nylon fibers. The more leggings (and other synthetic garments) we buy, the more profit flows back to the companies extracting and refining crude oil.

This isn't a coincidence. The fashion industry's shift toward cheap, synthetic fabrics was partly driven by petroleum companies looking for new markets for their products. Your leggings are, quite literally, a petroleum product—and every purchase supports the continued extraction and processing of fossil fuels.

When you buy synthetic leggings, you're not just making a fashion choice. You're participating in a system that benefits oil companies while contributing to pollution at both ends: during production and throughout the lifespan of the garment.

Toxic Chemical Additives to Clothing Manufacturing

A 2024 Study found that:

"Different chemical compositions were observed between cotton and artificial fabrics, with 3 times higher concentrations observed in clothing for children than for adults. Dermal contact via sweaty clothes may be a major exposure pathway for 2,4-di-tert-butyl-phenol (contributing 39.1% to total exposure); thus, it is recommended to avoid rewearing sweaty clothes to minimize human exposure."

Rethinking Your Athletic Wardrobe

The good news? You have alternatives. Natural fibers like organic cotton, hemp, and bamboo offer breathability and comfort without the microplastic shedding. Yes, they may cost more upfront, but they're often more durable and, crucially, they biodegrade naturally at the end of their life.

Even better: buying fewer, higher-quality pieces and wearing them longer is one of the most effective ways to reduce your environmental impact. That one pair of quality leggings worn for years beats five cheaper pairs worn briefly before disposal.

The Bigger Picture

The leggings industry is a perfect example of how convenience and affordability can mask larger environmental and ethical costs. By understanding where our clothes come from, how they're made, and what happens to them when we're done with them, we can make more informed choices.

Your next wardrobe decision doesn't have to be perfect—it just needs to be more conscious. Every garment you choose differently is a small but meaningful step toward breaking a system that profits from both petroleum extraction and environmental degradation. The research suggests that clothing-related chemical and particle exposures deserve far more attention than they currently receive. The good news is that understanding these dynamics offers practical insights. Regular laundering, proper storage away from contaminated environments, and selecting appropriate fabric types can all influence your exposure profile.

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