A new report from the International Union for Conservation of Nature (IUCN) has found that as much as 31 percent of the estimated 9.5 million tonnes of plastic that enters the ocean annually could be from sources such as tires and synthetic clothing.
These products can release "primary microplastics", which are plastics that directly enter the environment as "small particulates".
According to the IUCN, which released the report on Wednesday, they come from a range of sources.
These include synthetic textiles, which deposit them due to abrasion when washed, and tires, which release them as a result of erosion when driving.
The report identified seven "major sources" of primary microplastics: Tires, synthetic textiles, marine coatings, road markings, personal care products, plastic pellets and city dust.
"Our daily activities, suc