Knowing of no studies my ...

Knowing of no studies my assumption is yes, they will erode to micro-particles by tires which also emit micro-particles from flex and friction, as a kid sweeping the sidewalks in front of a business in the morning tire dust was the main part, it's heavy so doesn't go far without a wind.

A lot of it isn't water soluble and as a cyclist when you wash shorts & socks it floats and goes down the drain last, so, rinsing riding clothing is likely a good way to collect samples on this !! :)

We need to get ahead of these things and get diligent about them, if it's poisonous it affects everyone and assuming it is values the risk shown elsewhere by plastics now nano-sized very disturbing as they haven't been tested under controls and already "in the wild" like this idea.

The strategy is fine to reuse things yet not w/o controlled testing on living organisms first a minimal step to ask.