I do think the theory elsewhere in this thread about the different spectral distribution could be significant. This is why apparently non-UV blocking sunglasses can make UV damage worse: the pupils open wider when visible light is blocked and so let even more UV in. If you just skew the spectrum of some light source toward the UV without increasing the overall luminous intensity, presumably it could cause some health risks in a similar way.
I do think the theory elsewhere in this thread about the different spectral distribution could be significant. This is why apparently non-UV blocking sunglasses can make UV damage worse: the pupils open wider when visible light is blocked and so let even more UV in. If you just skew the spectrum of some light source toward the UV without increasing the overall luminous intensity, presumably it could cause some health risks in a similar way.