Car tyres are major source of ocean microplastics - study

[muriel_volestrangler]

More than 200,000 tonnes of tiny plastic particles are blown from roads into the oceans every year, according to research.

The study suggests wind-borne microplastics are a bigger source of ocean pollution than rivers, the route that has attracted most attention to date. The analysis focused on the tiny particles produced by tyres and brake pads as they wear down.

It estimated that 550,000 tonnes of particles smaller than 0.01mm are deposited each year, with almost half ending up in the ocean. More than 80,000 tonnes fall on remote ice- and snow-covered areas and may increase melting as the dark particles absorb the sun’s heat.
...
“Roads are a very significant source of microplastics to remote areas, including the oceans,” said Andreas Stohl, from the Norwegian Institute for Air Research, who led the research. He said an average tyre loses 4kg during its lifetime. “It’s such a huge amount of plastic compared to, say, clothes,” whose fibres are commonly found in rivers, Stohl said. “You will not lose kilograms of plastic from your clothing.”

https://www.theguardian.com/environment/2020/jul/14/car-tyres-are-major-source-of-ocean-microplastics-study

Full paper available:

Atmospheric transport is a major pathway of microplastics to remote regions

Abstract
In recent years, marine, freshwater and terrestrial pollution with microplastics has been discussed extensively, whereas atmospheric microplastic transport has been largely overlooked. Here, we present global simulations of atmospheric transport of microplastic particles produced by road traffic (TWPs – tire wear particles and BWPs – brake wear particles), a major source that can be quantified relatively well. We find a high transport efficiencies of these particles to remote regions. About 34% of the emitted coarse TWPs and 30% of the emitted coarse BWPs (100?kt?yr?1 and 40?kt?yr?1 respectively) were deposited in the World Ocean. These amounts are of similar magnitude as the total estimated direct and riverine transport of TWPs and fibres to the ocean (64?kt?yr?1). We suggest that the Arctic may be a particularly sensitive receptor region, where the light-absorbing properties of TWPs and BWPs may also cause accelerated warming and melting of the cryosphere.

Introduction
Global annual plastic production reached 359 million tonnes in 20181 and, consequently, plastic pollution in freshwater2, marine3 and terrestrial4 ecosystems has received a lot of attention recently. Plastics are released into the environment as macroplastic (>5?mm)5, microplastic (1??m to 5?mm)6 and nanoplastic (<1??m)7 particles that can fragment into smaller sizes via photodegradation, physical abrasion, hydrolysis and biodegradation8. Plastics can affect coral reefs9, marine10 and terrestrial animals11, as well as human health12,13.

An important source of plastics is road traffic emissions14,15. Kole et al.14 reported global average emissions of tyre wear particles (TWPs) of 0.81?kg?year?1 per capita, about 6.1 million tonnes (~1.8% of total plastic production). Emissions of brake wear particles (BWPs) add another 0.5 million tonnes. TWPs and BWPs are produced via mechanical abrasion and corrosion16,17.
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https://www.nature.com/articles/s41467-020-17201-9

[hunter]

1. We breathe that as well.

All the missing tread on the tires we replace goes somewhere.