Mass pm2.5 and pm10 emissions per vehicle-km.

That doesn't seem particularly relevant when some of the other things are highly poisonous?

Why would you focus on that when the review is talking about studies showing health impacts and only mentions tires once, explaining that general environmental dust becomes "road dust" when kicked up by tires?

That's a good point, but it might not be the whole story. It's possible that tailpipe emissions are worse for your health than small rubber particles from tires