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Doctors issue warning about effects of LED streetlights on health

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Re: Doctors issue warning about effects of LED streetlights on health

#61

Earlier quoted context omitted.

Studies involving 5 subjects are not capable of being rigorous. Considering this with equal weight as LHC discoveries is harmful. Please stop.

At posting, I didn't have time to provide more references. You'll see I've given three more references below. Sources include Acta Physiologica, SPIE, and Neuroscience Letters. They discuss different effects of illumination color temperature in human systems. I posted the initial reference as an entry point to follow literature on potential effects of illumination color temperature on human sleep, or perhaps circadia…

The first article isn't valid as it's paywalled and the abstract doesn't mention any studies; it could be someone's well-educated opinion.

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?

Re: Doctors issue warning about effects of LED streetlights on health

#62
Any sources to studies done on the effects of light at different Kelvins? I'm really surprised as I would have expected LED light with more blue and looking natural to be preferable to orange Sodium Vapor lights. The sun which is our main light source puts out a wide spectrum. I'm surprised the lower wattage LED street lamps could cause actual health problems. I'm usually in bed during sleeping hours and not really exposed to the new blue LED street lights installed recently in my neighborhood though.

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.

Re: Doctors issue warning about effects of LED streetlights on health

#63

I would argue that people with those crazy LED headlights are even worse. Since I often work late, I get the pleasure of being temporarily blinded as a white dwarf passes by at 45mph regularly.

I'm not sure how these are legal, I'm in my twenties with 20/20 and only somewhat sensitive to light but even the normal ones are absolutely blinding to the point where I'm really not sure what I would do (other than have already crashed) without the "focus on the white line to the right" trick.

Re: Doctors issue warning about effects of LED streetlights on health

#64
post #57
post #38

Earlier quoted context omitted.

And don't even get me started on the LED eye melters that cyclists are running these days. Some are about as bright as car headlights, but the spread and aim are inferior - especially since the folks that run those invariably seem to point them up from the horizontal. I keep thinking about mounting a 8 D cell maglight on a gimbal on my handlebars to give them a photon in-kind response.

If you see the biker then I think the lights did a good job. I suppose you could make an argument that it could blind people and they hit someone/something but I never heard of that happing - I only hear bikers getting hit because they were not seen.

i'm a cyclist and i sometimes have to stop and get off my bike and wait for an oncoming cyclist to pass me (eg, on a multipath). it's not necessarily the brightness, it's that it's not constructed to be visible (and/or illuminate the road) without also blinding oncoming traffic. fortunately i haven't ever hit someone or something while blinded by an oncoming cyclist, but that's in spite of the crap bike light, not because it did a good job.

Re: Doctors issue warning about effects of LED streetlights on health

#65

> "In addition to its impact on drivers, blue-rich LED streetlights operate at a wavelength that most adversely suppresses melatonin during night." 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.

The main issue doctors are alarmed about is how the increased blue light affects circadian rhythm and not the fact that we're exposed to it. Our bodies interpret blue light as a signal that it's daylight and we should be active. All sorts of biological processes are tied to it. Significant blue light at night screws the entire system up. Focused blue light can improve alertness and other functions. That's why light t…

> That's why light therapy has seen some significant successes in treating seasonal affective disorder, some forms of depression

I'd urge some caution there.

Re: Doctors issue warning about effects of LED streetlights on health

#66

Any sources to studies done on the effects of light at different Kelvins? I'm really surprised as I would have expected LED light with more blue and looking natural to be preferable to orange Sodium Vapor lights. The sun which is our main light source puts out a wide spectrum. I'm surprised the lower wattage LED street lamps could cause actual health problems. I'm usually in bed during sleeping hours and not really e…

LED spectra are usually tiny, sharp spikes, the home ones are getting slightly better, but the good ones are rather pricy. Incandescent or halogen bulbs feel more natural to me and their spectra look different

Re: Doctors issue warning about effects of LED streetlights on health

#67
post #64
post #57

Earlier quoted context omitted.

If you see the biker then I think the lights did a good job. I suppose you could make an argument that it could blind people and they hit someone/something but I never heard of that happing - I only hear bikers getting hit because they were not seen.

i'm a cyclist and i sometimes have to stop and get off my bike and wait for an oncoming cyclist to pass me (eg, on a multipath). it's not necessarily the brightness, it's that it's not constructed to be visible (and/or illuminate the road) without also blinding oncoming traffic. fortunately i haven't ever hit someone or something while blinded by an oncoming cyclist, but that's in spite of the crap bike light, not be…

Yes, me too. I'm a daily bike commuter and am quite sympathetic to the being seen aspect. This goes way beyond that in some cases. Case in point: a good chunk of my ride goes through the Portland Springwater corridor. This is a dedicated bike/pedestrian path. Much of it is unlit at night. I've seen these riders a half mile ago (~2 minutes) and by the time we're getting close enough to matter their lights are blinding. It's like a driver who refuses to dim their high beams for oncoming traffic.

Re: Doctors issue warning about effects of LED streetlights on health

#68
post #38

Earlier quoted context omitted.

And don't even get me started on the LED eye melters that cyclists are running these days. Some are about as bright as car headlights, but the spread and aim are inferior - especially since the folks that run those invariably seem to point them up from the horizontal. I keep thinking about mounting a 8 D cell maglight on a gimbal on my handlebars to give them a photon in-kind response.

I think part of it is a reaction to the poor bicycle infrastructure in many cities. Bright lights have stopped cars from hitting me at night a couple of times. While I'm simpathetic to other people (I try not to point them in people's eyes) there aren't that many other options.

I live in Portland, OR, e have pretty good bike infrastructure. If the goal is to be seen, there are indeed other options. LED glow or area lights are probably more effective than the eye melters pointing towards the sky and much less hostile.

Re: Doctors issue warning about effects of LED streetlights on health

#69

Title is misleading; it's not LED streetlights, it's the color temperature of LED streetlights. While the article raises a few good points, color temperature isn't new; it's not like LEDs have some inherent issue that impacts health.

True, but there's a real problem with people and places using lights with far too high a temperature, and even when shopping for home LED lights it's surprisingly difficult to find low temperature lights that aren't low on lumens output. 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.

LIFX makes [IMO] pretty great LED bulbs with controllable temperature. They don't require a central hub like Phillips Hue, and you can find them on sale right now since the newer model is smaller and fits more fixtures. http://www.lifx.com/products/white-800?variant=933783339

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.

Re: Doctors issue warning about effects of LED streetlights on health

#70
post #38

I would argue that people with those crazy LED headlights are even worse. Since I often work late, I get the pleasure of being temporarily blinded as a white dwarf passes by at 45mph regularly.

And don't even get me started on the LED eye melters that cyclists are running these days. Some are about as bright as car headlights, but the spread and aim are inferior - especially since the folks that run those invariably seem to point them up from the horizontal. I keep thinking about mounting a 8 D cell maglight on a gimbal on my handlebars to give them a photon in-kind response.

As a cyclist commuter who was hit by a clearly negligent car driver on Sunday in broad daylight, I fully support any measure to make bicyclists more noticed on the streets. In the absence of fully grade separated bike lanes, bicycles can only do so much to protect themselves against 4,000lbs of metal.
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