Old news, and something you've likely heard of before:
http://www.uvlightburns.com/What should be banned also are maintenance people who don't know about, or pay attention to, the condition of the lighting fixtures used in their facilities...and installers who use an open-type, unprotected (no metal grille) high-bay fixture in a school gym.
Actually, it would be good to have self-extinguishing metal halide lamps be the norm (I've never seen them for sale, anywhere, though), except it's probably a moot point now that T5, CFL and LED high bays will be the norm instead.