What the house sheds

The rug

1 to 60 fibres per cubic metre of indoor air, against 0.3 to 1.5 outdoors

Dris and colleagues sampled indoor and outdoor air in Paris. Indoor air carried 1 to 60 fibres per cubic metre against 0.3 to 1.5 outdoors, and between 1,586 and 11,130 fibres settled on every square metre of floor each day. A third of the fibres were petrochemical.

What changes it. Hard floors hold less settled fibre than synthetic carpet, and what settles can be removed before it is stirred up again.

Sources: Dris 2017

The sofa and the curtains

1.7 to 16.2 particles per cubic metre inhaled at breathing height

Vianello's team put a breathing mannequin in three Danish apartments and analysed what it inhaled. Every sample carried microplastic, between 1.7 and 16.2 particles per cubic metre, and polyester made up 81 percent of the synthetic fibres.

What changes it. Cotton, linen and wool shed cellulose and protein rather than polymer.

Sources: Vianello 2019

The floor, where children sit

29 to 110,000 micrograms of PET per gram of house dust across 12 countries

Zhang and colleagues measured PET, the polyester in drink bottles and fleece, in house dust from 12 countries and found between 29 and 110,000 micrograms per gram. Infants, who spend the day on the floor with hands in their mouths, had the highest estimated intake for their body weight.

What changes it. Vacuuming and then wet mopping removes settled dust before it is disturbed.

Sources: Zhang 2020 · Soltani 2021

The open window

0.81 kg of tyre wear per person per year, global average

Tyre wear is among the largest sources of microplastic anywhere, and the fine fraction travels on the air. Kole's review put the global average at 0.81 kilograms of tyre wear per person per year. How much of the fine fraction reaches a living room depends on distance from the road, and that step has not been measured indoors.

What changes it. Distance from heavy traffic is the variable. Closing windows at rush hour changes little for the day as a whole.

Sources: Kole 2017

The air purifier

13 of 20 lung samples carried polymer; whether a filter changes that is inferred, not measured

Amato-Lourenço's team found polymer fibres and fragments in 13 of 20 human lung tissue samples. A HEPA filter captures particles well below the size of these fibres, so it should catch them. That has been inferred from filter physics, not measured in living rooms.

What changes it. Mechanical HEPA filtration is the only purifier type with a physical reason to work on fibres. Ionisers do not remove them.

Sources: Amato-Lourenço 2021

What nobody has measured

How much of the dust that settles in a lived-in room ends up inside a person. Every figure above is a concentration in air or dust. The step from there to the body has been estimated, not measured.

The cutting board

7.4 to 50.7 g of polyethylene shed per person per year

Yadav's group chopped carrots on polyethylene and polypropylene boards and counted what came off. Their estimate for one person's kitchen was 7.4 to 50.7 grams of polyethylene a year, tens of millions of particles.

What changes it. Wood, bamboo and glass boards do not shed polymer. The knife still wears a wooden board, but what comes off is cellulose.

Sources: Yadav 2023 · Oligomer study 2026

The nonstick pan

About 9,100 particles from a single surface crack

Luo and colleagues used Raman imaging on scratched nonstick coatings. A single surface crack released around 9,100 particles. A coating that had broken through released 2.3 million.

What changes it. An intact coating sheds little. The condition of the pan matters more than owning one.

Sources: Luo 2022

The kettle

11.8 million nanoparticles per millilitre on a new plastic kettle's first boil

A 2025 study boiled water in new polypropylene kettles and counted 11.8 million nanoparticles per millilitre in the first boil. Release fell 73 percent by the tenth boil and 96 percent after 150.

What changes it. Steel and glass kettles have no polymer at the boil. A new plastic kettle sheds most in its first boils, which is the case for running and discarding them.

Sources: npj Emerging Contaminants 2025

The tea bag

11.6 billion microparticles in one cup brewed with a plastic tea bag

Hernandez's team steeped plastic tea bags at brewing temperature and counted 11.6 billion microparticles and 3.1 billion nanoparticles in a single cup.

What changes it. Paper bags and loose leaf brew without a polymer mesh.

Sources: Hernandez 2019 · Banaei 2024

Leftovers in the microwave

Up to 4.22 million microplastics per square centimetre of container after three minutes

Hussain and colleagues microwaved food-grade containers for three minutes and measured up to 4.22 million microplastics per square centimetre of container. Other researchers challenged the counting method in a published correspondence and the authors defended it. Both are linked below.

What changes it. Glass and ceramic in the microwave, plastic for cold storage only, keeps heat and polymer apart.

Sources: Hussain 2023 · Correspondence 2024 · Rebuttal 2024

The sponge

6.5 million fibres per gram of melamine sponge worn away

Su's team abraded melamine foam sponges and measured 6.5 million fibres shed per gram of sponge worn away. Their estimate for one month of global sales ran to 1.55 trillion fibres.

What changes it. Cellulose sponges and cloths scrub without melamine.

Sources: Su 2024 · Follow-up 2025 · Kitchen sponges 2026

The water bottle

About 240,000 particles per litre of bottled water, 90 percent of them nanoplastic

Qian and colleagues imaged bottled water particle by particle and found about 240,000 per litre, roughly 90 percent of them nanoplastics too small for earlier methods to see.

What changes it. Filtered tap water in glass or steel carries the fewest measured particles.

Sources: Qian 2024 · Storage study 2026

What nobody has measured

How much of what a cutting board sheds stays on the food, and how much rinses off with the vegetables. The counts above are what comes off the board, not what reaches the plate.

The toothpaste

Some, not all toothpastes tested contained microplastic, depending on the market

A 2023 systematic review pooled toothpaste analyses from several countries. Pastes from some markets contained microplastic and pastes from others contained none. Polyethylene on the ingredient list is the sign to look for.

What changes it. A polyethylene-free ingredient list settles it for any single tube.

Sources: Systematic review 2023

The scrub and the glitter

4,594 to 94,500 microbeads released in one use of a facial scrub

Napper's group extracted microbeads from facial scrubs and estimated between 4,594 and 94,500 beads released per use.

What changes it. Salt, sugar and ground seeds exfoliate without polymer, and plastic glitter has plant-cellulose alternatives.

Sources: Napper 2015 · Napper 2016

Contact lenses

About 90,000 particles a year at ten hours of daily wear, after sunlight exposure

Sun's team exposed lenses to the equivalent of 90 days of sunlight and measured what they shed. Their estimate was about 90,000 particles a year at ten hours of daily wear. Lenses kept from sunlight shed none in the study.

What changes it. The pathway here is the eye, and what happens next has not been studied.

Sources: Sun 2023

Wet wipes

77 to 568 particles shed per dry sheet under a fixed wiping force

A 2022 study wiped non-woven sheets under a fixed force and counted between 77 and 568 particles per dry sheet. Wet wipes shed fewer, 21 to 190.

What changes it. Cotton cloth and water do the same job without a polymer sheet.

Sources: Wiping study 2022 · Wipes 2026

The washer and dryer nook

Up to 120 million microfibres vented by one household dryer in a year

Tao's team ran a household dryer and captured the exhaust. A single machine can vent up to 120 million microfibres a year, 1.4 to 40 times what a washing machine releases to water.

What changes it. Line drying skips the vent entirely. A natural-fibre wardrobe sheds cellulose instead.

Sources: Tao 2022 · O'Brien 2020 · De Falco 2019

What nobody has measured

Whether a warm shower carries particles from the water into the air you breathe. Tap water has been counted; shower air has not.