Car tyres, fleece jackets and tea bags all shed microplastics
Microplastics are plastic particles between a thousandth of a millimetre and 5 millimetres across. Some are made small on purpose, like the microbeads in face scrubs. Most come from larger things breaking down: bottles, fishing nets, tyres grinding against roads, and synthetic clothes shedding fibres in every wash.
The two routes matter. Primary microplastics start life tiny, including glitter, clothing fibres and the pellets called nurdles that manufacturers melt into other products. Microbeads in cleansers replaced natural scrubbing materials such as ground almond shells, oatmeal and pumice, and plastic grit is blasted at engines and boat hulls to strip paint, picking up cadmium, chromium and lead as it wears down. Secondary microplastics form when sunlight, waves and wind fragment bigger debris, which is why so many particles have ragged, uneven shapes.
Laundry is a striking source. Each garment can release more than 1,900 fibres, fleeces far more than others, and an average 6 kilogram load may send over 700,000 fibres down the drain. Tyres, made partly of synthetic rubber, crumble into dust as they roll. Filters on washing machines can reduce what reaches sewage works.
The scale is hard to picture. A 2014 estimate put between 15 and 51 trillion pieces in the oceans, weighing 93,000 to 236,000 tonnes, and one projection says their weight will exceed that of fish by 2050. They drift in air indoors and out, turn up in soils never deliberately treated with plastic, and a 2023 study linked them to lower soil fertility and crop yields. People mostly take them in by mouth, through water, salt, seafood and milk.
Fragments keep shrinking into nanoplastics, below a micrometre and invisible to the eye. These can cross cell membranes and have been tracked into fish organs, including the brain, though their effects on human health remain poorly understood. The word itself is usually credited to a 2004 paper by the Plymouth marine biologist Richard Thompson, although earlier uses exist.
Source: Microplastics
