Exposure to air pollution is associated with around seven million premature deaths per year across the world. When we think of urban air pollution, diesel exhaust emissions are often portrayed as a key culprit – rightly so, given previous research findings. However, our latest research shows that dust from brake pads could be more harmful to our lungs.
Not just metal, some brake pads have asbestos. I’m surprised more people don’t know about this…
https://www.epa.gov/asbestos/i-have-changed-my-brakes-past-should-i-be-worried-about-asbestos-exposure
Edit: maybe someone should archive that link before Trump shuts down the EPA.