Yes. Synthetic clothing and textiles are the single biggest source of the microplastic fibres found in indoor air, and indoor air carries two to five times more of these fibres than the air outside. A peer-reviewed lung study found that inhaled textile microfibres, including nylon, actively impair the airway's ability to repair itself.
Part of our series on plastic in outdoor wear - start with 'Why Outdoor Wear Shouldn't Be Made of Plastic'.
How do fibres get from a jacket Into the air?
Every time synthetic fabric flexes, rubs, or brushes against itself or another surface, it releases tiny fragments of plastic fibre. Unlike shedding in a washing machine, this happens constantly, indoors, while a garment is simply being worn or even folded into a drawer. Air currents keep the lightest of these fibres suspended for hours before they eventually settle as household dust.
Is indoor air really worse than outdoor air?
For microplastics specifically, yes. Studies measuring airborne fibre concentration have consistently found indoor environments carry two to five times more microplastic than outdoor air, with synthetic textiles - clothing, carpets, upholstery, curtains - identified as the dominant source. Good ventilation helps dilute the concentration, but it doesn't remove the source sitting in the wardrobe.
What happens when you inhale a microfibre?
Research published in a leading respiratory journal found that inhaled textile microfibres, including polyester, can impair the airway epithelium's ability to repair itself after damage - the same repair mechanism the lungs rely on to recover from everyday irritants like dust and smoke. The finest fibres, the kind produced in greatest volume by recycled polyester, are also the ones most capable of reaching deep into the lungs.
Does it matter what the fibre Is made of?
For the immediate irritation, any inhaled particulate is unwelcome. But natural fibres like Merino wool are biodegradable proteins that the body can process and break down; synthetic microplastic fibres are inert and effectively permanent once inhaled. Microplastic fibres have already been detected in human lung tissue, blood, and placental tissue - evidence that they don't simply pass through.
Reducing what you breathe at home
Ventilation, regular dusting with a damp cloth rather than dry, and vacuuming with a HEPA filter all reduce airborne concentration. The most direct lever, though, is what's in the wardrobe: fewer synthetic garments means less shedding at the source, all day, every day, whether you're wearing them or not.
Related reading: Why Outdoor Wear Shouldn't Be Made of Plastic · Is recycled polyester more sustainable than virgin polyester? · Merino Wool vs Synthetic Fleece: What's Actually Warmer?
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Source: American Journal of Respiratory and Critical Care Medicine.