Microplastics: what they are and how to reduce them

Plastic never fully goes away — it just breaks into smaller and smaller pieces. Microplastics are everywhere: in soil, rivers, oceans, the air, and increasingly in studies of the human body. Taking sensible steps to reduce your exposure and contribution makes sense even while the science continues to develop.

What microplastics are

Microplastics are small plastic particles, typically defined as less than 5 mm in size. They come in two forms:

• Primary microplastics — manufactured at small size deliberately, such as plastic pellets used in industrial production ("nurdles"), and microbeads formerly used in cosmetics and personal care products (now banned in many countries).
• Secondary microplastics — formed when larger plastic items break down through UV exposure, weathering and physical abrasion. A plastic bottle, a car tyre, a synthetic fleece — all shed particles over time.

Nanoplastics are even smaller fragments (typically below 1 micrometre) that form as microplastics continue to break down. They are harder to study but of increasing scientific interest because smaller particles may behave differently in biological systems.

Main sources

Research consistently identifies a handful of dominant sources:

• Tyre and road wear: as tyres abrade against road surfaces, they shed rubber and plastic particles. These are washed into drains, rivers and the sea by rain. Studies suggest tyre wear is one of the largest sources of microplastics in aquatic environments.
• Synthetic textile fibres: washing polyester, nylon, acrylic and other synthetic fabrics releases microscopic fibres. A single wash cycle can release hundreds of thousands of fibres, which pass through most wastewater treatment systems and enter waterways.
• Fragmentation of larger plastic items: packaging, bags, bottles and agricultural plastic (silage wrap, polytunnels) break down outdoors. Litter on land or in water gradually generates secondary microplastics.
• Paints and coatings: marine paints and some architectural coatings shed microplastic particles, particularly in coastal environments.
• Dust and indoor sources: synthetic carpets, upholstery, and furnishings shed fibres indoors. House dust is a vector for microplastic exposure, particularly for young children who spend time on floors.

What we know — and don't — about health

This is the area where it's most important to be measured and honest about the state of the evidence.

What the research does show:

• Microplastics are pervasive in human bodies — detection studies have found them in a wide range of tissues.
• In laboratory settings and animal studies, microplastics and associated chemical additives (plasticisers, stabilisers, flame retardants) can cause inflammatory responses and other biological effects at sufficient concentrations.
• Some of the chemical additives that leach from plastics — such as certain phthalates and bisphenols — have more established evidence of endocrine-disrupting effects; this is a related but separate concern from the particles themselves.
• The health effects of microplastics in humans at real-world exposure levels are not yet well characterised. This is an area where the science is genuinely still developing.

Reducing shedding: laundry and clothing

Since synthetic textile fibres are one of the major domestic sources of microplastics reaching waterways, how you wash your clothes matters.

• Wash synthetic clothes less often. Not every wear needs a wash — airing clothes and spot-cleaning stains means fewer cycles and far less fibre release over time.
• Use cooler water and shorter cycles. Higher temperatures and longer mechanical action increase fibre shedding. A 30°C quick wash is gentler on fibres than a hot, long cycle.
• Wash full loads. Less friction between garments in a fuller load means less fibre abrasion. Half-loads cause more fabric-to-fabric rubbing.
• Use a laundry filter bag. Products like the Guppyfriend bag are designed to capture fibres shed during the wash. Studies show they can reduce the fibres that exit the machine, though no filter is 100% effective. Some washing machine manufacturers now offer inline drum filters.
• Choose natural fibres where practical. Cotton, wool, linen and hemp shed organic fibres that break down in the environment rather than persisting as plastic. When buying new clothes, this is a worthwhile factor alongside durability and care requirements.
• Wash new synthetic garments inside out. New synthetic clothing tends to shed more in the first few washes. Turning items inside out also reduces surface pilling.

Reducing exposure at home

A few straightforward steps can reduce the microplastics you and your household ingest or inhale:

• Don't heat food in plastic containers. Heat accelerates the release of plastic particles and chemical additives. Use glass, ceramic or stainless steel for heating and storing food, particularly anything acidic or fatty. This is one of the most practical steps you can take.
• Reduce single-use plastic in contact with food and drink. Plastic packaging in contact with food, especially under heat or sunlight, is a route to ingestion. Choosing glass or cardboard packaging where available, and reusable containers, reduces this.
• Ventilate and dust regularly. Indoor air contains microplastic fibres from synthetic textiles and furnishings. Regular ventilation and damp-dusting (rather than dry-dusting, which redistributes particles) reduces settled fibres. This is especially relevant if you have young children.
• Filter tap water if you are concerned. Tap water in many countries contains low levels of microplastics. A good-quality water filter (reverse osmosis removes particles effectively; many activated carbon filters also help) reduces this exposure. Whether this is necessary depends on your water quality and personal circumstances. Bottled water is not obviously better — some studies have found it contains comparable or higher levels of plastic particles.
• Avoid single-use plastic cups and bottles. Using a reusable bottle or cup avoids the slow release of particles from plastic containers, especially in warm conditions.

The bigger picture

Individual actions on microplastics matter, but the scale of the problem is primarily systemic. Tyre wear requires infrastructure and vehicle policy responses. Industrial plastic production creates the feedstock for environmental microplastics. Wastewater treatment systems need upgrading to capture finer particles.

What individuals can do is meaningful at the margins: reducing plastic use lowers the total material in circulation, supporting fewer cars and better public transport reduces tyre wear, and choosing natural fibre clothing reduces fibre shedding. But the bigger levers are policy and industry standards — producer responsibility for packaging, requirements for microplastic filters in washing machines (already introduced in some countries for new appliances), and investment in wastewater treatment.

Caring about microplastics and acting on plastic pollution more broadly are the same thing. The practical steps below overlap considerably with general plastic reduction.

Microplastics reduction checklist

• Wash synthetic clothes less often and at lower temperatures.
• Run full loads in the washing machine.
• Consider a laundry filter bag or inline washing machine filter for synthetic garments.
• Never heat food in plastic containers — use glass, ceramic or stainless steel.
• Choose natural fibre clothing when buying new items.
• Damp-dust and ventilate your home regularly.
• Use a reusable water bottle rather than single-use plastic.
• Reduce overall plastic packaging in contact with food, especially under heat.
• Filter tap water if concerned about your local supply (check your local water quality report first).