Even if it happens from time to time, the amount of dusk is going to be ridiculously small (you don't release that much dust from damaging a rock, let alone glazing, unless you grind it).
And keep in mind that this is a subway station, places where the pm2.5 levels are routinely extremely high because of the dust released by train breaks, so a microscopic amount of uranium dust is really negligible in such an environment.
And keep in mind that this is a subway station, places where the pm2.5 levels are routinely extremely high because of the dust released by train breaks, so a microscopic amount of uranium dust is really negligible in such an environment.