Are TRWP a source of marine microplastic pollution?

The presence of TRWP in oceans has not been demonstrated, but peer-reviewed studies have suggested that around 2-5% of generated TRWP is transported to estuaries.

Some modelling exercises have suggested that TRWP are transported by natural processes to the marine environment; however, the presence of TRWP in the marine environment has not been demonstrated through field studies.

TIP is supporting ongoing studies into TRWP pathways – focusing on air, soil, sediment and estuaries.

A 2018 two-part, peer-reviewed study (part one, part two) estimated that as little as 2-5% of TRWP is transported to estuaries. The study suggests that most TRWP finds its way to roadside soils or is removed from the road surface as runoff. A small fraction is released to the air. TIP is sponsoring a new study that will refine these numbers and scientific understanding of the flows, transport, and sinks of TRWP in the environment.

A 2018 peer-reviewed and journal-published study into micro(plastic) fluxes in Lake Geneva basin concluded that most of the plastic input is likely to be accumulated in lake sediments – not reaching the marine environment.

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