blue light associated with prostate and breast cancer

AsI recall, it takes only a brief exposure — think incandescent white nightlight bulb — to suppress melatonin production. Then it takes half an hour to an hour for the body to resume produccing melatonin. It’s the melatonin that suppresses breast cancer (which is why night shift workers and people in areas newly supplied with nighttime electricity show an increase)

https://www.google.com/search?client=firefox-b-1-d&channel=tus&q=melatonin+night+shift+cancer

You can buy a spectrometer kit (several variations, varying prices) from PublicLab.
https://store.publiclab.org/collections/bulk/products/lego-spectrometer-kit?variant=8187504787563

EDIT
Here’s the spectrum from one of the claimed low-blue-light 110v bulbs

See blue light associated with prostate and breast cancer - #23 by BurningPlayd0h from DominikM for spectra

I used my kit spectrometer to check the claims of bluelight suppression. A lot of it is hype — f.lux for example changes the apparent color temperature by adding more red, rather than removing blue. The spectrometer shows plenty of blue light still being emitted from the computer screen (whether fluorescent or LED lit).

I swapped amber LEDs into half our home flashlights, for nighttime use, and for room lighting we use amber LED bulbs or “bug light” compact fluorescents for evening light during the short-day half of the year.

Doing that cured our insomnia, which had gotten bad when we replaced all our incandescents with “white” compact fluorescents some years ago.

I think CCT is actually still a huge part of what’s happening there. Even 2700K light from a blackbody source will have far less of the blue end of the spectrum compared to 4000K.

https://curiosity.com/topics/this-is-how-little-blue-light-it-takes-to-disturb-your-sleep-curiosity/

has several links including this one: https://www.lrc.rpi.edu/resources/newsroom/pdf/2010/CircadianLight_8511.pdf

Yep.
It’s what matters.

4000k is better, 3000k is even better, 2700k is even better than 3000k, and 2000-2200k has almost no blue light.

I’d love to test 1800k LEDs myself.

Could someone use Luminus 3030 Cubes in Virence’s large MCPCB?

The N219b has that large blue spike, yet it is sold as photobiologically safe:

I want to learn more about how to determine the RG0 Blue Light safety requirement.

do High CRI LEDs score better than Low CRI?
does low Color Temperature score better?
etc

“Photobiologically safe: exempted from bluelight hazard” sounds like marketing hype to me.
But apparently it’s referring to a European regulation.

The “blue light hazard”
https://www.google.com/search?client=firefox-b-1-d&channel=tus&q=“blue+light+hazard”
is damage to the eye, perhaps the claim is this emitter is not strong enough for that problem to arise.

https://www.google.com/search?client=firefox-b-1-d&channel=tus&q=Photobiologically_Safe

A few years ago I corresponded with one of the researchers in the field, who said that at a European scientific conference on the subject they were already seeing industry PR people there to deny any possible problem with the blue-white LEDs their companies were pushing as “so cheap they pay for themselves in saved electricity costs” —- too cheap to meter, basically.

LOLOLOL You’re right. When they use words like ” exempt from bluelight hazard” it sounds more like bureaucratic BS than scientific fact.

Opt Lett. 2014 Feb 1;39(3):563-6. doi: 10.1364/OL.39.000563.
Phosphor-converted LEDs with low circadian action for outdoor lighting.

This is the main reason I want most of my flashlights in 2000K or below. Blue light affects my sleep at night, so keeping my flashlights at 2000K won’t give me any melatonin suppression. All my lights in the house are halogen and i cover up all sources of LEDs with red or black tape. 2000K is a little spooky sometimes though since the color temp looks like a candle flame, so i have a bunch of 2700K flashlights on hand too… just an excuse for more flashlights.

No such thing as a “Lee minus blue” filter or nuttin’?

This light is claimed to be for medical purposes. It says, it contains very little of blue wavelength. I wonder how true is it and what the led sits inside…

(ordered one a few days ago)

Doctor here.

Having an association does not mean that it causes cancer. What’s more likely (and again, I’m speculating) is that people exposed to more blue light have habits and lifestyles that make them more likely to get cancer. Considering the prostate is not even exposed to light, I would guess that this is the more likely scenario.

/\ … Now that hypothesis …. makes sense. Thanks FindThisHumerus. :beer:

Nice to to get some back up sometimes :innocent:

Yes, this is a known effect which is measured and light sources can be ranked by impact on ipRGC (melanopic function).
See below a list of light sources with different CCT, blue %age and their relative melanopic potential :

(Source)

The article spells out very clearly that its reduced melatonin (and possible other changes in hormones due to that) which is directly causally linked to blue light exposure, this then increases risks of hormone-related cancers.

thanks , so is 3000k safe?.
considering a 2000k if it comes to all this.

thanks.

WARNING

reading this thread my cause cancer or worse still it may overstimulate your hypochondria.

thanks , - so what do you use daytime use?.
I have a 5600k E21A for daytime use.
I am even considering 3000 or 2000k for daytime use to be safe.