Every time you wear a polyester shirt, nylon leggings, or acrylic sweater, tiny plastic fibres break free from the fabric. Some end up in your washing machine. Some become airborne. Some stay on your skin.
And increasingly, science is finding them inside your body.
Microplastics Are Now Inside Us
This is no longer theoretical. Researchers have found microplastics in:
- Human blood — a 2022 study in Environment International detected microplastics in 77% of blood samples. PET (the plastic in polyester) was the most common type found.
- Human lungs — a 2022 study in Science of the Total Environment found microplastics in 11 of 13 lung tissue samples from living patients. Fibres (like those from synthetic clothing) were the most common shape.
- Human placenta — a 2020 Italian study found microplastics in 4 of 6 human placentas examined, raising concerns about foetal exposure.
- Breast milk — a 2022 study detected microplastics in 75% of breast milk samples tested.
- Brain tissue — a 2024 study found microplastics in human brain tissue, with concentrations significantly higher than in liver and kidney samples.
Synthetic textiles — primarily polyester, nylon, and acrylic — are the largest single source of microplastic pollution globally, responsible for an estimated 35% of all microplastics entering the ocean.
How Clothing Microplastics Enter Your Body
Route 1: Inhalation
You breathe in microplastic fibres constantly. Indoor air studies have found an average of 16.2 fibres per cubic metre — and concentrations are higher in homes and bedrooms than outdoors. Synthetic clothing, bedding, carpets, and upholstery all shed fibres into the air.
These fibres are small enough to reach the deepest parts of your lungs. Once there, they can trigger inflammation, oxidative stress, and immune responses. Occupational studies of textile workers exposed to synthetic fibre dust show higher rates of respiratory disease.
Route 2: Skin Contact
Nano-scale plastic particles (smaller than microplastics) may be able to penetrate the skin barrier — especially when the skin is warm, sweaty, or damaged. While research on dermal absorption is still emerging, several factors increase potential exposure:
- Sweat — opens pores and may facilitate particle transfer
- Friction — mechanical rubbing between skin and synthetic fabric breaks fibres loose
- Heat — polyester traps heat, creating a warm microenvironment where chemical leaching increases
- Duration — clothing sits against your skin for 12-16 hours a day, far longer than any skincare product
Route 3: Ingestion (via Laundry)
Every time you wash synthetic clothing, you release microplastic fibres into the water supply:
These fibres pass through most water treatment plants, enter rivers and oceans, are consumed by marine life, and work their way back up the food chain — into seafood, drinking water, sea salt, and eventually your body.
What Do Microplastics Do Inside the Body?
Research into health effects is still early but growing rapidly. Here's what studies have found so far:
Inflammation
Microplastics trigger inflammatory responses in human cells and tissues. A 2021 review found that exposure causes oxidative stress, cytokine release, and cellular damage in laboratory studies. Chronic low-level inflammation is linked to cardiovascular disease, metabolic disorders, and cancer.
Chemical Carriers
Microplastics act as vectors for other toxic chemicals. They absorb and concentrate heavy metals, pesticides, phthalates, and persistent organic pollutants from the environment — and can release these chemicals when inside the body. A single microplastic particle can carry a cocktail of toxic substances into your tissues.
Gut Disruption
Studies in animals have shown that ingested microplastics can alter gut microbiome composition, increase intestinal permeability ("leaky gut"), and trigger immune responses in the digestive tract.
Reproductive Concerns
The presence of microplastics in human placenta and breast milk raises concerns about foetal and infant exposure during critical developmental periods. Animal studies have shown effects on fertility, pregnancy outcomes, and offspring development.
Polyester Is the Biggest Source
Not all synthetic fabrics shed equally:
Natural fibres like cotton, linen, wool, and silk do shed tiny fibres — but these are biodegradable and break down in the environment. Synthetic fibres persist for decades to centuries.
How to Reduce Your Microplastic Exposure from Clothing
The Most Effective Step: Wear Natural Fibres
Cotton, linen, wool, silk, and hemp don't shed microplastics. Period. Switching even a portion of your wardrobe from synthetic to natural fibres directly reduces your exposure — both from wearing and washing.
If You Have Synthetic Clothes
- Wash less frequently — every wash releases hundreds of thousands of fibres. Spot-clean when possible.
- Use cold water — lower temperatures reduce fibre breakage and shedding
- Use a microfibre-catching laundry bag — bags like Guppyfriend capture approximately 86% of shed fibres
- Use a shorter, gentler cycle — less agitation means less fibre shedding
- Air dry — tumble drying breaks fibres loose and sends microplastics into the air
- Avoid polyester fleece — the single worst fabric for microplastic shedding
For Your Bedroom
You spend 7-9 hours in bed breathing in whatever your bedding sheds. Switch polyester sheets, pillowcases, and duvet covers to cotton or linen. This alone reduces your nightly microplastic inhalation significantly.
The Bottom Line
Microplastics from synthetic clothing are now in our blood, lungs, and organs. The full health consequences are still being researched, but the direction of the science is concerning — inflammation, chemical transport, gut disruption, and reproductive effects.
The simplest way to reduce your exposure is to know what your clothes are made of and choose natural fibres when you can.