According to this UMSICHT study
(Bertling 2018), an average of around 998 g of these particles are produced per person
and year by car tyres, around 89 g by truck tyres, 15.6 g by bicycle tyres and 228 g by
the abrasion of bitumen in asphalt.
That appears to be a collection of European state funded programs putting out that information, so it’s not like they’re a think tank or anything. I checked out their sponsors and didn’t find any fossil fuel companies at least, and they list their sources.
Anyway, from that German study it sounds like it really is mainly cars. I was surprised at that because heavier vehicles damage road surfaces exponentially more because of their higher contact pressure. I would guess with microplastics the important factor is cumulative surface area in contact with the road, which cars would dominate.
I was going to raise an objection about whether it was “car” tyres because I only saw vehicle tyres in the article, but I found this report:
https://www.lifebluelakes.eu/wp-content/uploads/2021/05/Factsheet-microplastics_tyres_Blue-Lakes.pdf
That appears to be a collection of European state funded programs putting out that information, so it’s not like they’re a think tank or anything. I checked out their sponsors and didn’t find any fossil fuel companies at least, and they list their sources.
Anyway, from that German study it sounds like it really is mainly cars. I was surprised at that because heavier vehicles damage road surfaces exponentially more because of their higher contact pressure. I would guess with microplastics the important factor is cumulative surface area in contact with the road, which cars would dominate.