What Microplastics Are and Where They Come From
Launch library · evergreen read
Microplastics are plastic fragments smaller than five millimetres, a size threshold chosen partly because pieces this small behave differently in the environment, moving through water and even air in ways larger plastic debris does not. They fall broadly into two categories based on how they came to be that size.
Primary microplastics are manufactured small from the start, such as microbeads once common in some cosmetic products. Secondary microplastics are far more common and form when larger plastic items, from packaging to synthetic clothing fibres and tyre wear, gradually break down through sunlight, friction and weathering over time.
Because they are so small and widespread, microplastics have been found in waterways, soil and even remote environments far from obvious pollution sources. Research into their long term effects is still developing, but their sheer persistence, since plastic does not truly biodegrade, is what makes their spread a lasting concern. Even a garment that seems durable can shed thousands of tiny synthetic fibres with every wash, feeding into waterways well before the fabric itself ever wears out.