A story in three parts:
1. "The company found that a car’s four tires collectively emit 1 trillion ultrafine particles — of less than 100 nanometers — per kilometer driven. These particles, a growing number of experts say, pose a unique health risk: They are so small they can pass through lung tissue into the bloodstream and cross the blood-brain barrier or be breathed in and travel directly to the brain, causing a range of problems."
https://e360.yale.edu/features/tire-pollution-toxic-chemicals
2. "... smaller ultrafine particles of <36.5 nm size generally penetrated least. [...] 95% protection is achievable for smaller particles of 11.5 to 20.5 nm sizes."
https://www.mdpi.com/1660-4601/15/9/1958
3. Respirators work. Over the coming years, you will probably see more and more articles come out about the health risks of airborne micro and nanoplastics -- mostly in the context of their accumulation in untreated, indoor air. But it is worth knowing that there is something you can do about your exposure outdoors, as well. The more people normalize this behavior, the less stigmatized it becomes. The only thing worse than a health risk is the stigma attached to the tools that help us mitigate it. Since electric vehicles weigh more -- and thus emit more tire dust -- outdoor air isn't getting any friendlier in places with car-centric infrastructure