Although getting some UV might be good for people with a vitamin D deficiency, doing this safely and without other consequences (like degrading plastics or bleaching colors in your office or bedroom) seems hard, and I don’t recommend trying to do this.
I have been thinking about this recently (prompted again by vitamin D being a significant factor in protecting against COVID, but also it gradually making its way to the top of the “well-supported health things I ought to try” list), and am curious for details here. That is, suppose I get a bunch of RayVio 293 nm LEDs, and I want to figure out how to use them in a way that’s safe and minimally does other bad things. What tools should I be buying to measure things, what sorts of damage should I be looking for, what sorts of things might make sense?
The biggest reasons why I do not try to do this myself are:
I haven’t done enough research to know what a good dose is in terms of wavelength, intensity, and time
It seems hard to build a source that gets the dose right, without basically building a tanning bed
I think it’s hard to know what dose you’re actually getting
It’s also possible that I am unreasonably worried about shining artificial UV light on myself.
Assuming you have an answer for 1 (and that paper looks promising for having a good answer to this), you need to build a source that illuminates your skin in some reasonably even way. This can be hard, since most light sources radiate over a wide angle, so that you get 1/r^2 drop off in intensity. For example, just now I used my lux meter to measure the intensity of the light near my desk on my forehead and my stomach, and they varied by almost a factor of two. One potentially pretty neat way to fix this would be to use some kind of large collimator like the one in that video that Robert Miles mentioned. The intensity will drop off much more slowly with distance from the source, which should make it easier to get a predictable dose, plus our intuitions about dose from the sun will will still sort of work (for example “The part of my skin that is farther from the sun but is normal to the sun’s rays is getting more”). If I did build a big sunlight simulator like that, I would be tempted to add in a little UV.
I recently learned that a common way to measure UV dose is to paint something with a white pigment that absorbs UV and reflects visible/IR light, and see how much it heats up when illuminated. I’m not sure how well this would work when the dose rate is less than 10 mJ/cm^2/minute as in that paper. You probably would just want to use a UV index meter, like they did in the Nature paper you linked.
What would be good is to have some kind of inexpensive cumulative dosimeters that you could place on yourself and around in the area where the UV is so that you can check that you’re not inadvertently getting way more or way less than you want. A quick Google search for “UVB dosimeter” looks like there are options, but I have not looked at any of them enough to know if they’re any good.
I have been thinking about this recently (prompted again by vitamin D being a significant factor in protecting against COVID, but also it gradually making its way to the top of the “well-supported health things I ought to try” list), and am curious for details here. That is, suppose I get a bunch of RayVio 293 nm LEDs, and I want to figure out how to use them in a way that’s safe and minimally does other bad things. What tools should I be buying to measure things, what sorts of damage should I be looking for, what sorts of things might make sense?
The biggest reasons why I do not try to do this myself are:
I haven’t done enough research to know what a good dose is in terms of wavelength, intensity, and time
It seems hard to build a source that gets the dose right, without basically building a tanning bed
I think it’s hard to know what dose you’re actually getting
It’s also possible that I am unreasonably worried about shining artificial UV light on myself.
Assuming you have an answer for 1 (and that paper looks promising for having a good answer to this), you need to build a source that illuminates your skin in some reasonably even way. This can be hard, since most light sources radiate over a wide angle, so that you get 1/r^2 drop off in intensity. For example, just now I used my lux meter to measure the intensity of the light near my desk on my forehead and my stomach, and they varied by almost a factor of two. One potentially pretty neat way to fix this would be to use some kind of large collimator like the one in that video that Robert Miles mentioned. The intensity will drop off much more slowly with distance from the source, which should make it easier to get a predictable dose, plus our intuitions about dose from the sun will will still sort of work (for example “The part of my skin that is farther from the sun but is normal to the sun’s rays is getting more”). If I did build a big sunlight simulator like that, I would be tempted to add in a little UV.
I recently learned that a common way to measure UV dose is to paint something with a white pigment that absorbs UV and reflects visible/IR light, and see how much it heats up when illuminated. I’m not sure how well this would work when the dose rate is less than 10 mJ/cm^2/minute as in that paper. You probably would just want to use a UV index meter, like they did in the Nature paper you linked.
What would be good is to have some kind of inexpensive cumulative dosimeters that you could place on yourself and around in the area where the UV is so that you can check that you’re not inadvertently getting way more or way less than you want. A quick Google search for “UVB dosimeter” looks like there are options, but I have not looked at any of them enough to know if they’re any good.