I'm sufficiently sensitive to vape fumes that my eyes and throat can burn for a couple kf days after exposure to concentrations too low for me to smell. I only work out why I'm feeling ill when it's too late to do anything about it. (Cigarette smoke is nowhere near as bad).

In my experience, very few vapers are willing to desist if I see they've got the equipment and ask them not to use it. Their addiction prevents them empathizing with the injury they're causing to others.