Doctors issue warning about effects of LED streetlights on health
theconversation.com
theconversation.com
In any case, the original article's title mentions white LED streetlights -- so I guess making that clear in the title here might help.
Pretty much anything over 3000K looks horribly blue at night, and if it wasn't such a massive pain to find them I'd prefer <2000K.
Some of the newer "warm tone" CFL bulbs appears to do better better on these aspects. [0]: http://minerva.union.edu/newmanj/Physics100/Light%20Producti...
http://www.designingwithleds.com/the-new-cree-tw-series-led-...
Still 20x+ the cost of a normal bulb, and the tech probably won't work in 5 years, but it works well enough as a dumb bulb once the temperature is set that even when they inevitably go out of business or get acquired and shut down by Google, it should still be the temperature you want.
My last car was smashed by an idiot who didn't know how to back out of a parking spot, so rather than waiting for weeks while the body shop replaced the whole right side my car, I just traded it in for a new lease; a 2016 of same model. The new model has those stupid lights and I absolutely hate them. They're even unnatural and obnoxious to the person driving the car, not just the poor souls they're blinding.
Unfortunately, most cars will likely have them within the next few years.
Based on what?
No, absolutely not.
Lights are to help the cyclist SEE.
To be SEEN you need reflectors. [1]
Worse, if a cyclist's frontlight is blinding other cyclists coming at him it means they're failing both the others AND themselves, as: The oncoming ones can't see shit and are more likely to make a mistake and the rider themselves isn't illuminating the ground ahead of them so they can't actually see where they're going.
I've been commuting by bike, year-round, for 17 years. While my commute home may require lights, my morning commute requires them. (It's at 3:00 a.m. and some stretches have no lights.) If my headlight was parallel to the ground, it would not let me see where I am going. Oh, it will show a person or vehicle, but it won't let me see the road. It's aimed at a spot X feet in front of me, enabling me to see debris on the road, as well as anything huge.
Properly aimed or not, a headlight is only going to let a motorist (or anyone) see you if they are coming towards you. I can see them coming, too. A good reflective vest and secondary lights (helmet, side, etc.) is necessary to let people see you from behind or the side. (The vest is useless if the car is running without its headlights on, which has happened to me a few times in the morning.)
Sorry. Didn't see you.
If you were coming from behind me, you wouldn't have seen my headlight, anyway. That's why I have a taillight and a reflective vest.
The proper ones, like one sees on BMW, etc., don't blind people.
I posted the initial reference as an entry point to follow literature on potential effects of illumination color temperature on human sleep, or perhaps circadian rhythms, through action on a hormone known to be critically involved in sleep. I didn't suggest it was the end of the story. My post was on topic and it contributed to the discussion.
Would be glad to review data you think interesting.
http://onlinelibrary.wiley.com/doi/10.1111/apha.12552/abstra...
http://proceedings.spiedigitallibrary.org/proceeding.aspx?ar...
http://www.sciencedirect.com/science/article/pii/S0304394008...
The second article covers how bright light can be without being painful, and doesn't mention sleep or melatonin. Or at least the abstract does, again the article is paywalled, but at least it involves 500 participants.
The third study only covers 12 participants. I'll grant there may be thousands of these studies, each with a handful of subjects. Is there some statistical way to stitch the results together in any meaningful fashion - or would that just result in a low p-value?
I wonder if this ends up saving thousands of lives by decreasing fatigue in drivers. The blue light argument seems like absolute hogwash; we're exposed to orders of magnitude brighter blue light every day. It's called daylight, and the streetlights dont't even emit UV.
Only because for more than a century the overwhelming majority of domestic light bulbs aped the colour temperature of candles, so that nightlight unconsciously became associated with yellowness.
There's nothing inherently 'right' about warm yellow light, it's entirely subjective based upon conditioning. For example people in hot, arid climates describe blue-white light as relaxing because it is associated with the cooler early morning. To them, yellow light is the scorching midday Sun. Having lived exclusively with 'daylight' domestic lighting for nearly a decade I agree with them.
The solution to disruptive street lighting is not to fiddle with colour temperatures but to turn off the lighting when it's not required. A residential street doesn't need to be illuminated at 03:00 if there are no cars or pedestrians, but managing that would require motion sensors. Easier just to let the bulb burn away through the night.
If you think the problem with light at night is hogwash you need to read it again. Bright light, especially blue light makes your body react like it's daytime. Do you really think people have forgotten about the sun? You only hurt your own understanding by being so quick to dismiss others.
You're preaching to the choir. I'm well aware of the melatonin-reducing effects of blue light, but the streetlights are a drop in the bucket compared to phones, televisions, and tablets. The one time I actually want to have my melatonin levels suppressed is when it's late and I'm operating heavy machinery.
We could mandate that people driving at night must drink at least one cup of coffee per half hour, and it would make them be more awake in the short term, but it would be a terrible idea for similar reasons.
Focused blue light can improve alertness and other functions. That's why light therapy has seen some significant successes in treating seasonal affective disorder, some forms of depression, and other disorders. But there's no free lunch involved here; you're more or less manipulating your circadian rhythm, and eventually, those periods of increased alertness are effectively offset. With the light therapy and SAD example, that's exactly what you want to do: you're effectively telling your body that it's daytime, you need to be active instead of sluggish, and winter is just trying to screw with you. It should help eliminate oversleeping (common with SAD), but that doesn't mean you suddenly need less sleep. The same thing would apply here as well.
I'd urge some caution there.
For example, daylight led's were touted as making it easier to identify cars involved in criminal activity because you can see the color of the vehicle more easily. But how many times has this actually made the difference in solving a crime?
The blue is special -- 473 nanometers -- due to the solid state physics of the semiconductor.
There is indeed an ongoing search for white LED designs that produce less glaring blue without sacrificing overall efficiency, but counterintuitively it's a hard design problem. People also want warmer light in their houses, so the problem is not limited to street lighting.
The safety regulations have a special place in hell for "retinal blue" light. As it turns out every wavelength from UV into the IR has a set of weighting functions for estimating the overall hazard exposure. It's possibly a rare example of a truly science based regulation.
I live in Seattle and I really like the new lights, they're way better than the dingy orange HPS lights. It's easier for my eyes to adjust when walking out of a bright apartment, and I can see more details. Anecdotally, I've also seen fewer vagrant types in the newly lit areas.
As someone who has always been interested in Astronomy I do worry about light pollution. Having worked at Observatories I do know that only red light is used due to it's low impact on light pollution.
You don't want to "cool it" - that means more blue! You want to warm it with less.
It is an opportune moment to make the recommendation, since folks are converting to LED so rapidly.
BTW, they also failed to mention increased light pollution due to scattering.