I really hope, someone makes a cheap spectrometer as a smartphone accessory. That would be the best way to quickly assess the properties of light sources. Beyond the health impact, one wants to know the light spectrum when e.g. selecting lamps for fish tanks or plant lighting.

As a very coarse but easily available poor-mans spectrometer, I have been taking pictures of a greycard with my camera in raw-mode. Looking at the histogram balanced for a fixed color temperature, e.g. sunlight, for the r,g,b-channels gives very different results depending on different light sources. While you don't see a true spectrum, just the strength of the blue vs. the green and red channel usually is very revealing.