…analysis of more than 4,000 people living in 11 separate regions of Spain established a link between heavy exposure to the LED lighting and a doubling of the risk of prostate cancer, as well as a 1.5-times higher chance of breast cancer.
… the “blue light” emitted by the LEDs may be disrupting the body’s circadian rhythm, which in turn affects hormone levels. Both breast and prostate cancers are hormone-related.
… The research team at the University of Exeter and the Barcelona Institute for Global Health said their findings may also implicate the nighttime use of mobile phones and tablets, which also emit blue light, in cancer development.
… blue-spectrum light decreases the production and secretion of the melatonin hormone.”
Well. This is interesting.
I have done some research on light and sound frequency effects on cells etc. There is a ton to be found online. Now you got me thinking again. Oh boy.
Actually blue light has been known to be carcinogenic and affect sleeping for many years already. This is the same reason why Samsung, Apple, and others have added a Blue Light Filter feature to their phones that makes the colors warmer (less cool/blue) so it causes less harm to your eyes, health, and ability to sleep. There’s also a popular program for your PC called f.lux that makes the colors warmer at night time and colder in the day time, which I installed on my PC. It works great.
That’s why for me I only use 4000k or lower for my night time EDCs.
In standarized world there is a term: photobiological safety. Light can have many effects on human body. strenght, wavelenght, PWMs - these all take effect on us.
Man, I wish my knowledge allow me to give you the right answer. But it does not and since we’re talking about human safety (safety always 1st) I do not dare to answer. But I’m nearly sure some requirements (made upon research) are given in occupational hearth and safety guidelines. (OSHA?)
My understanding is that blue light specifically is the type of light that impacts the sleep cycle, as opposed to red or green. And for this reason, warmer/cooler CCT lights have different effects. I've easily observed this in my own life: one room of my house has 2700K lighting, and I will fall asleep if I try to read a book in that room. The other areas of my home have 4000K to 5000K lighting, and I have no issues reading and staying awake there.
Anyway, this becomes an issue when significant blue-light invades spaces where it hasn't always been. Cool-CCT streetlights in particular could be an issue, as they shine at night. If people aren't aware of the impacts of blue light on their sleep schedules and/or don't accommodate for that impact in their life, they'll have sleep cycle disruptions. This can range anywhere from decreased quality of sleep to straight-up insomnia. In fact, I had seen studies showing this impact comparing dark vs. brightly lit neighborhoods already (wish I still had that source), and I'm not surprised at all that adding more blue light would strengthen the effect.
My answer is to move into my warmly lit room at the end of the day and wind down there. Also to limit screen usage and/or blue-light filter the screen. And lastly, blackout curtains ;)
TL;DR: It's long been known that light affects sleep, more blue spectrum means stronger impact, and sleep impacts everything else
It’s like a magic cancer-wand. Point it at a bad guy and bam! Dude dies of cancer, and doesn’t even get to die in his sleep. Teaches him right for lurking around an alley in the dark.
I knew there was a reason why I kept all those crappy LED maglites.
I thought using a cool white for not so long on and off during a night duty LEO shift would be ok as It wasn’t excessive.
not sure, maybe best stick to NW/ Warm
For those concerned and using firefox, opera or chrome without a built in color temp changer, this add on is very handy. It’s not automatic, but just leaving it on all the time isn’t that bad either.
The quotes from the article seem to answer a lot of the questions here. The issue is constant, bright, high-CCT street lighting being linked to changes in sleep patterns/hormones.