What it is
Polyester fibre is PET again — the drink-bottle polymer drawn into thread. With nylon, acrylic and elastane, synthetics make up roughly two-thirds of global fibre production. In indoor air and dust, fibres — not fragments — are the dominant form of microplastic, which makes textiles the exposure you breathe rather than eat.
Where you meet it
Activewear, fleece, school uniforms, sheets and doonas, curtains, carpet, microfibre cleaning cloths — and the lint screen that proves the point every load.
What the research shows
- A 6 kg wash releases up to ~700,000 microfibres — acrylic worst, polyester ~496,000 (University of Plymouth, Marine Pollution Bulletin, 2016) lab.
- Simply wearing polyester sheds fibres to air on the same order as washing sheds to water (ES&T, 2020) lab — you cannot launder your way out.
- A vented tumble dryer can discharge up to ~120 million microfibres a year (City University of Hong Kong, ES&T Letters, 2022) lab.
- The Australian data point: a Macquarie University survey of 32 Sydney homes found microplastic fibres in the dust of every single house, with carpeted homes carrying roughly double, and young children the most exposed (Environmental Pollution, 2021) human obs..
On what it does to us: inhalation and dust ingestion are modelled as the dominant indoor routes lab; the extreme occupational case (“flock worker’s lung”) shows very high fibre inhalation can harm airways human obs.; and FSANZ currently assesses food-chain microplastics as unlikely to pose an immediate health risk, noting gut absorption of intact particles is likely ≤0.3% (FSANZ) agency.
What I do
The bedroom was my big move — eight hours a night breathing next to your sheets adds up, so bedding went to bamboo, cotton and wool through 2025. Synthetics that remain get washed less, cold, in full loads; Queensland sunshine line-dries everything; and the floors get regular vacuuming on the Sydney-dust logic. France now mandates microfibre filters on new washing machines — a retrofit filter is on my list.
The honest bit
Most dust fibres are still natural (cotton, wool) — though those carry dyes and finishes of their own — and microfibre cloths clean brilliantly because they shed and snag. I still own microfibre cloths; they’re just being replaced by cotton as they die, and they never see the tumble dryer. Dose, not purity.