Some cities are taking another look at LED lighting after AMA warning

https://www.washingtonpost.com/national/health-science/some-cities-are-taking-another-look-at-led-lighting-after-ama-warning/2016/09/21/98779568-7c3d-11e6-bd86-b7bbd53d2b5d_story.html

by petethomas • 10 years ago

121 105 10 years ago

washingtonpost.com

CodeWriter23• 10 years ago

Can't they simply get units with a 2800K white point?

GarrisonPrime• 10 years ago

I'm sure the LED manufacturers will take full advantage of this opportunity to create "true-light healthy LEDs", for which they can charge double or triple.

semi-extrinsic2• 10 years ago

You can already get some (actually really nice) LEDs for your house that change color to lower temperature (more orange/red) as they dim, mimicking the effect of dimming incandescents. It does make for a nice cozy atmosphere. As you say, they're not cheap, but I'd consider them strongly if I were redecorating.

Edit: it's confusing that a cool blue light is a high temperature, and a warm orange light is a low temperature.

jws• 10 years ago

Because of your eye's sensitivity to different frequencies, the "warmer" colors require more energy for the same effective lighting. Hence, highway departments choose the "daylight" option to save energy.

userbinator• 10 years ago

All the studies I've found seem to say something along the lines of "blue light disturbs sleep", which seems like exactly the needed effect if you're driving at night.

jackyinger4• 10 years ago

Yeah, until you drive out of the highly lit area. Then your eyes will have to take some time to adjust to the low light.

droopyEyelids• 10 years ago

You're thinking of 'promoting wakefullness' like a cup of coffee that has an immediate effect that wears off when it leaves your system.

'Disturbing sleep' means they alter your hormone production & release, which is something that begins to affect you over weeks and months.

High color temperature lights disturb sleep- without promoting wakefullnes.

abz102• 10 years ago

The light has an effect during the night as it blocks the melatonin hormone from kicking in. It takes about an hour of darkness for the hormone kick in and make you sleepy. On very long occasional drives it's probably safer to trade some sleep disturbance for a more wakeful drive. If it's your daily commute it'll probably mess up your sleep.

bunderbunder3• 10 years ago

Seems like there might also be an opportunity here:

  - Install the ones that keep people awake along highways and suchlike.
  - Install lights that don't disturb sleep so much in neighborhoods.

Bud• 10 years ago

No. The lights aren't effective at keeping sleepy people more awake in the moment. They're effective at disrupting sleep over time by disrupting the hormonal system.

They should be banned in favor of lower-color-temperature lights.

ianai3• 10 years ago

The blue light also burns out retinae. It's been linked to cataracts. It seems like an industrial regulation is needed to me.

criley22• 10 years ago

They should be banned in favor of lower-color-temperature lights.

As the article indicates, they are less effective at disrupting sleep than a LCD monitor or smartphone.

If we're banning an outdoor light for being less disruptive than your phone, should we also mandate Flux style warm color phones at night by law?

criley22• 10 years ago

I thought this was already common around the world, say in Europe.

Where 4 lane / artery / highways get brighter, whiter (bluer) lights, while 2 lane feeders and smaller roads have warmer yellow lighting.

It produces an interesting nighttime aerial effect as the color indicates the nature of the street.

I can't find any source to corroborate so I'd love if someone with more worldly travel experience could corroborate.

I first became aware of the phenomenon playing Cities: Skylines, a European developed city builder game which features the multi-colored street lights in European skins.

semi-extrinsic2• 10 years ago

IDK, but this could simply be an effect of bigger roads getting more frequent upgrades, and/or bigger roads tolerating a larger cost per light since the total cost per meter of road is already higher.

jackyinger4• 10 years ago

Yes! I am not crazy! Seriously, do we really need lights that make the city as light as in the day? I'd rather give my retinas a rest.

bunderbunder3• 10 years ago

I'm not sure that we do need them, at least not to the extent that they're used.

http://darksky.org/light-pollution/lighting-crime-and-safety...

mjevans• 10 years ago

Yes, enough to see enough. Like artificial moon-light.

lake99• 10 years ago

as light as in the day

It's got nothing to do with intensity, which would be impossible to achieve, for all practical purposes. The article misused the word here. Rather, it's about color temperature.

I think this problem is overblown, because I've not heard similar complaints leveled against mercury-vapour lamps. I've grown up around them nearly all my life.

jackyinger4• 10 years ago

When you replace 1:1 vapor laps with LEDs an adequately lit parking lot becomes lit like a stage.

Though to your color temp point, if we could get lower color temperature that'd be great. IIRC red LEDs are much more efficient than full spectrum anyway.

misnome• 10 years ago

What exactly is "unseen blue light"?

betaby• 10 years ago

It's perfectly "seen". LED without filter has blue spike in spectrum. http://www.ledsmagazine.com/content/dam/leds/PrintArticles/v...

jackyinger4• 10 years ago

I think they mean that there is a lot of blue light emitted, but it is not super obvious because they emit longer wavelength light as well (reds & greens).

_0w8t2• 10 years ago

While that may improve sleep, it may also made driving less safe. With blue light it is easy for eyes to focus. In fact there is a theory that significant increase in myopia during the last 100 years is caused by eye work under artificial light without blue color, like from ordinary light bulb...

Edit: I should have written "without blue light in spectrum eyes work harder". Basically any deviation from the spectrum of Sun have cosequences for eyes performance long term

http://www.eyedolatryblog.com/2014/02/myopia-may-be-reversib...

honkhonkpants• 10 years ago

First time I've heard that it is easy to focus blue light.

https://www.google.com/search?q=is+it+hard+to+focus+on+blue+...

_0w8t2• 10 years ago

I should wrote about focusing in light without blue component, not focusing under blue light.

http://www.eyedolatryblog.com/2014/02/myopia-may-be-reversib...

witty_username• 10 years ago

Apart from psychological effects, there is no reason why blue light should be easier to focus (the change in refractive index for different wavelengths is marginal).

vvpan• 10 years ago

This follows tit-for-tat the story of every other street lighting development in the past. It gets invented, implemented, lauded and then disappointment sets in. At least according to a fairly exhaustive book on the topic called Disenchanted Night: The Industrialization of Light in the Nineteenth Century[1]

[1] https://www.goodreads.com/book/show/350025.Disenchanted_Nigh...

ianai3• 10 years ago

Do car headlights while you're at it.

jqkeller• 10 years ago

I've worked on a few street light retrofit projects and the AMA warning is a little overblown and frankly immediately outdated.

This is off the cuff, but it comes down to circadian rhythms being influenced by the color of light. Before artficial light, the sunrise and sunset have a softer light with a lot more red wavelength in it. This would correspond more closely with the color of light from an incandescent, like 2500-3000 Kelvin. The mid day light has a lot more blue wavelength in it relatively, where it is much more of a White light, I think daylight is like 15,000K. The high pressure sodium, HPS, lights have an orange light in the 2,200K range. The majority of LED street lights being installed are 4000-5000K, so they have a lot more of the blue light. Essentially the blue light tricks your brain into thinking it's mid day and messes with your sleep patterns.

The first generations of LED street lights could really only effectively make the 4000-5000K light. With new generations coming out every 3 months or so though they have been able to create models that can generate the 2500-3000K warm red light, but they're not quite as energy efficienct as the 4000K lamps, maybe 10% or something. The 2500K is actually better for the Dark Sky movements as well and a lot of cities are moving to specify these warmer temperature for those reasons.

There are a whole bunch of other things going on as well. The road way lighting standards were designed around the light patterns of a HPS lamp and haven't been updated to reflect the light patterns possible with LEDs, hence a lot of LED projects have too bright of streets.

For the sleep pattern issues, when you're installing LED lights in your home, you want to put the warm lamps, 2500-3000K, lamps in bedrooms and such. Then for living spaces or offices you'd want to put the 4000K lamps to help keep you awake during the day. There are also lamps/fixtures available that will automatically tune the color output of the light to be in sync with the outdoors to help keep circadian rhythms in sync.

This company has been pushing the tunable lamps hard. http://www.planled.com/archives/portfolio-item/entraining-ci...

http://humancentriclighting.org/ This site appears to be fairly dead, but they were more of an independent group promoting it the last year or two.

keenerd8• 10 years ago

I think daylight is like 15,000K.

No, it is 5500K or 6500K depending on which metric you use.

pYQAJ6Zm• 10 years ago

I always felt confused between the 5500 / 6500 K pair. What metrics are involved?

internaut2• 10 years ago

This is off the cuff, but it comes down to circadian rhythms being influenced by the color of light. Before artficial light, the sunrise and sunset have a softer light with a lot more red wavelength in it.

That is right, which is why I have a nice project to use a heliostat with optical fibre to use as daylighting for a house interior.

The colour temperature shall have a nice warm glow in early morning and evening, which shall aid sleep preparation. I'll publish a log if I believe the project is successful.

Set it and forget it is the best smart house technology.

phasetransition3• 10 years ago

I'm head of engineering for a company that designs outdoor luminaires for industrial environments, but not street lights. We use LED and other technologies. Like so many things in life, there are aspects of the AMA directive with potential cause for concern, but also combined with a mixed bag of scientific underpinnings. If you have specific questions about LED physics or human vision, I'm happy to give them a go. I also can speak to some of the literature behind the AMA position paper.

raziel2701• 10 years ago

What temperature LED light should I have for my bedroom?

sokoloff• 10 years ago

For sleeping? I recommend Zero Fahrenheit Fahrenheit.

internaut2• 10 years ago

I have a Philips sunrise alarm clock that looks like a lamp.

I recommend that. It is a great lamp colour temperature and way to wake up.

phasetransition3• 10 years ago

Essentially any LED bulb that you can buy is a blue diode with a down conversion phosphor. The composition of the phosphor, and the relative amount of blue light vs. phosphor emissions shape our perception of color temperature for these LED sources.

Due to an effect called metamerism, our brains can perceive the same apparent color from sources with different underlying spectral power distributions (power vs. wavelength).

So in a sense, the color temperature of a black body does not have much underlying connection with the spectral power distribution of LED lamps.

With that substantial caveat, the lower the correlated color temperature of the bulbs that you purchase, the less of the overall spectral power is from the diode, and the more from the phosphors.

If there ends up being a link to blue light exposure for circadian effects then bulbs with lower CCT that have more emission from the phosphors are the safer bet.

bcook2• 10 years ago

You might be interested in https://en.wikipedia.org/wiki/Kruithof_curve and https://en.wikipedia.org/wiki/Color_Rendering_Index (high CRI).

amelius• 10 years ago

You can buy blue-blocking glasses. So perhaps they can fit these streetlights with these filters.

dpark5• 10 years ago

Of course you can do that. It's just a terrible idea because it drastically reduces the efficiency and output of the lights.

keenerd8• 10 years ago

Let's break down their claims.

unseen blue light

I have unread negative comments about this sloppy writing.

They also repeatedly use the word "intense" incorrectly. Intensity refers to candela. Not lumens or temperature.

The original LED streetlights had temperatures of at least 4000K, which produces a bright white light with a high content of unseen blue light.

4000K is actually considered fairly mellow. Above 6000K, then things start to get blue. The earliest white LEDs were around 10000K and terrible.

Now, however, LEDs are available with lower kelvin ratings and roughly the same energy efficiency as those with higher ratings.

And now the higher kelvin lights are even more efficient. White LEDs use phosphors to shift the blue light to longer wavelengths. This is a lossy process. Low-K tints require more phosphors and reduce efficiency. That said, 4000K looks so much nicer than 6000K that the loss is worth it.

“As a species, we weren’t designed to see light at night,” Siminovitch said.

We've had mastery over fire for as long as we've been a species. Darkness is unnatural to humans.

Moonlight is around 4100K. So it is even more "natural" than 3000K. Should we blot out the moon next?

it urged cities to minimize blue-rich outside lighting and recommended the use of LEDs no brighter than 3000K.

Confusing color temperature and brightness again.

And now from the AMA's press release:

Recent large surveys found that brighter residential nighttime lighting is associated with reduced sleep times, [etc]

It seems no one has blinds in their windows. I always carry an eye-mask with me too, just in case.

The AMA press release is very low on actual content so I can't comment on most of it. They are smart enough to avoid mentioning the "blue light causes eye damage" myth for example, sticking to meaningless wishy-washy statements.

If the people raising a fuss over LEDs actually cared, they would have been campaigning against mercury-vapor and high-intensity-discharge lamps for the past several decades. A 4000K LED puts out way less blue light than either of those technologies.

fian• 10 years ago

Moonlight is around 4100K. So it is even more "natural" than 3000K. Should we blot out the moon next?

I was on a hike in July during a full moon and those who were sleeping in open air (no tent or bivy bag) struggled to sleep through the night due to the moonlight.

This was in the North West of Australia, so daytime maximums were around 35C. It was too warm at night to zip your tent or bivy closed, so where possible you would try to position yourself so that you could shield yourself from the moonlight during the night.

There were quite a few afternoon nappers in the group until the moon waned a little by the second week.

keenerd8• 10 years ago

No one carried a bandanna that they could use as an eye mask? I've done that even when the night time low was 35C.

harlanlewis• 10 years ago

Even worse is the extreme latitudes in summer! I tried sleeping under just a mosquito net in Alaska when the sun stayed up until 2am and rose again by 4. I brought a sleeping mask but found it hard to keep on, as we'd encountered three separate grizzlies earlier that day…

At lower latitudes, a full moon over snow is stunning and surreal when you can get away from local light sources - no flashlight required. Light at night (of appropriate color temp) is quite natural.

sandworm1013• 10 years ago

Perhaps this is our bodies telling us something, a piece of our evolution. Perhaps we aren't meant to sleep in the open. We are easy prey at night. Sleeping in moonlight, out in the open, is dangerous for prey animals. A dislike for sleeping in moonlight might therefore be a survival tool. Those uncomfortable with moonlight were more likely to be sleeping under cover and less likely to be hauled off by lions.

spullara• 10 years ago

I sleep in a hammock on my balcony quite a bit and without covering your eyes it can be a real struggle when the moon is near full and the skies are clear. One thing mentioned elsewhere is the idea that darkness = safety. I can imagine that to be very true for humans.

Senji• 10 years ago

Should we blot out the moon next?

Why not? Lets fund an orbiter to create an artificial lunar eclipse exactly on full moon.

sandworm1013• 10 years ago

I would also submit that Kelvin is not an appropriate reference for the colour of LED lights. Kelvin only makes sense when discussing blackbody emissions, it is essentially a description of temperature. LEDs do not create light via simple heating. Their spectrum is not the smooth blackbody curve that the kelvin scale suggests. It is in fact a combination of several strong emissions at narrow wavelengths that combine to fool our senses into perceiving white light.

Proper discussion of harmful emissions from LEDs should instead speak of intensities at a particular wavelength and perhaps ratios between wavelengths rather than an outdated reference designed for blackbodies.

keenerd8• 10 years ago

While I agree with you from a standpoint of accuracy, Kelvin is still really useful. It also happens to map pretty nicely to how we perceive color.

The N-step MacAdam ellipse on a 2D CCx/CCy plane is what gets used when you dig into tint, but people love to reduce complex systems to a single number. And if you want a single number, temperature is the best we have.

I'm curious what your suggestion might look like in practice because it would be even more complex than the MacAdam ellipse.

ghostly_s• 10 years ago

CRI accounts for this, though it does not reveal the specific wavelength components. You can however be confident a 90+ CRI light source is not going to have an unexpectedly high intensity of any given wavelength.

thought_alarm• 10 years ago

My city used old-style mercury-vapor street lights up until the early 80s. For those who have never seen these lights, they have a bluish-white appearance but emit light only at a few very specific wavelengths, and almost none in the red spectrum. The effect is that under these lights a red car would look strangely black while everything else more or less looked normal color. I loved the effect.

I have fond childhood memories of seeing my street bathed in the bluish-white light from these street lights, especially during those long winter nights when the ground is covered in white snow. I am quite certain that these street lights did not produce a generation of "physiologically unwell" people.

My city has now begun switching to LED lights and I think they look terrific.

arpa• 10 years ago

These mercury-vapor lamps were used until 90-somethings where i used to live. People would say that until these bluish-white lamps were phased out by orange ones, people in the street would look as if they were dead; I would always counter with "they sure look as if they're alive now". Maybe because of childhood nostalgia I always preferred the bluish-white nights instead of that pervasive orange ones, especially during overcast winter nights where everything in thirty kilometer radius would become orange and unnatural. Clear nights with full moon were godsend.

But things are changing nowadays and our city also started using LEDs and by Moses, they are so much unbelievably better in all aspects! Even if they emit that "unseen blue" light, it is most definitely not worse than the insanely pervasive orange...

jacobolus5• 10 years ago

This is an obnoxiously dismissive comment build on ignorance and shoddy reasoning and an “I don’t care what you think just suck it up and stop complaining” approach to design/policy.

The moon is one (1) singular source of light with a known peak intensity, often blocked by trees or clouds, and only at its brightest one day every month. On a full moon night, the moon is high overhead, not directly in your field of view if you’re looking straight ahead.

LED streetlamps are a dozen or more point light sources, directly in the field of view, each one of them individually brighter than the moon. The 4000K LED streetlamps installed on my street last year have a very sharp spike in the short wavelength part of their spectral power distribution (come to my street and I’ll lend you some diffraction grating glasses to see the spectrum for yourself). The LED lamps are also incredibly bright, I’d say 2–4x the luminance of the prior streetlamps or the sodium lamps on nearby streets.

Because the new lamps are brighter, cities save money by using fewer of them, spaced more widely. This causes the light to be less even than past streetlamps, meaning some parts of the street are intensely illuminated and other parts are in shadows. The lamps are shielded at the top, but they shine out to the side at a very wide angle, meaning they still cause a ton of glare from a block away or more. When originally installed they had poor shielding in the direction of people’s second-floor bedroom windows. They’ve since fixed that problem and only people on the first floor still have light shining directly into their windows.

Seeing these and objects they illuminate in your peripheral vision causes the eyes to become bright-adapted (i.e. entirely knocks out night vision) making objects in shadow appear darker than under other lighting, and the whole scene to have very high contrast. (It takes something like a half hour to become dark-adapted once again.) The glare is extremely distracting. Overall they make the street feel like an industrial warehouse.

The light is not like fire, or past streetlamps.

Beyond that, the new lamps are not more energy efficient than modern sodium lamps. Indeed, if you make them more than twice as bright, they use substantially more energy than well made sodium lamps.

When I walk my dog at night I’ve taken to wearing orange safety glasses (basically plastic filters which block out the short-wavelength part of the spectrum). That I can see noticeably better after blocking half the light put out by these streetlamps indicates that there is some problem with their current design. (With the orange glasses, my rod vision continues to function properly.)

LED streetlamps should be at ~2700K CCT or below, with almost no light in the blue part of the spectrum. They should be no brighter than past streetlamps. They should be placed close together and not too high up, and shielded to mostly direct their light downward rather than sideways.

Under such circumstances they would be fine. (LEDs aren’t an inherently bad technology. They have the advantage that they last longer without needing to be replaced. This saves money for city maintenance departments.) Unfortunately current models on the market don’t meet those criteria.

Same story for car headlamps. The current LED headlamps are a safety risk (blinding pedestrians and other drivers with the glare). LED technology could be used to make fine car headlamps; it’s the ones currently on the market that are terrible.

keenerd8• 10 years ago

Yes, I was a little glib. But nonetheless life on Earth (not just our species) evolved with a 4100K light source at night.

You are confusing color temperature with how the lights are installed. If your streetlights were 4000K and spaced properly you wouldn't have an issue with them. The penny-pinching distribution (high lumens, wide angle, distantly spaced) of lights chosen by your city is at fault. That layout will create maximum glare and is the most miserable layout imaginable since distant lights will always be shining directly in your eyes.

ScottBurson• 10 years ago

Well ... the article is poorly written; clearly the author doesn't understand the science.

But you make some good points. I support your recommendations.

scythe2• 10 years ago

What matters isn't color temperature, but the presence or absence of light in the range 360-405 nanometers, which activates certain neurons in the retina that suppress melatonin secretion. This light can be "unseen" because visual receptors don't respond particularly strongly to it, so it can be masked by much stronger emissions of yellow light. However, it still has an effect. Color perception is irrelevant in this case.

http://press.endocrine.org/doi/abs/10.1210/endo-119-5-2201?j...

http://jap.physiology.org/content/110/3/619.short

Fires and the moon emit very little light at this frequency.

keenerd8• 10 years ago

405nm is violet. 360nm is UV. Yes, we are sensitive to it. But white LEDs emit none* of either.

*Future generation of LEDs might shift from indigo (445nm) to violet to improve color rendition, but cost will go way up and efficiency will go way down so I doubt it will be common. And some stores are already adding UV LEDs to their lighting in order to make florescents really pop.

Edit: and a reference, the datasheet for the latest and greatest XHP50 LED: http://www.cree.com/~/media/Files/Cree/LED-Components-and-Mo...

Spectral charts are on page 11. Peak emission is at 445nm. Beyond 415nm there is nothing.

Cheaper LEDs will use a longer wavelength of blue, typically around 475nm.

bcook2• 10 years ago

I think the author is inferring the https://en.wikipedia.org/wiki/Kruithof_curve. We apparently prefer dimmer light sources to be warmer.

pasbesoin• 10 years ago

Noticed in my parents' town with their recent deployment. The LED lights appear to be more tunable and/or actually tuned, to put light on the street while keeping it off of houses.

So, "blue" whatever. If you are keeping my yard dark so I don't have to pull the shades just to block out the light, well, win!

Of course, other areas that still feel the need to light up every square centimeter because security, YMMV.

I'll add that I find the current LED streetlight colors better than the orange sodium vapor "malaise" that we've grown so accustomed to.

hocuspocus• 10 years ago

Somewhat related, I've always wondered why outdoor solid shutters or blinds are a given in some countries/regions but nowhere to be seen in others, even though some residential areas are extremely polluted by artificial light at night.

keenerd8• 10 years ago

Those were historically used to prevent damage to window panes, not block light. They are popular in areas that were settled when glass was very fragile/expensive and receive strong winds. Pre-glass, they were used to keep weather from blowing through the house.

jkmcf2• 10 years ago

Meanwhile, the “dark sky” movement criticizes LEDs as a major contributor to what it calls the “light pollution” that humans cast into the night sky.

As a former, quasi-astronomer, nothing at night is more impressive than a star lit sky. My first night in Colorado was unbelievable.

0xffff2• 10 years ago

Really? I thought one of the major advantages to LED street lighting is that it is much more directional, so it leaks less light into the sky.

jkmcf2• 10 years ago

20+ years ago, sodium (?, same as below?) lamps were suggested but supposedly people didn't like how things looked (IIRC) in the light.

http://www.flagstaffdarkskies.org/for-wonks/lamp-spectrum-li... says low pressure sodium lamps significantly improve star viewing compared w/ LED due to the narrower spectrum.

Downvote science, bitches.

scythe2• 10 years ago

I'm not sure what the point was in the first place? Sodium lamps approach 200 lumens/watt. LEDs are whiter, but whiter light doesn't necessarily help you drive, does it? If the concern is colored signs, light the signs?

jacobolus5• 10 years ago

Big point #1 was federal subsidies and big new contracts for lighting vendors.

Big point #2 (an actual advantage now) is reduced maintenance cost because the lamps (theoretically) last longer between replacements.

The energy efficiency claims were always a red herring.

phonon• 10 years ago

Here is the actual AMA report.

http://darksky.org/wp-content/uploads/bsk-pdf-manager/AMA_Re...

A representative section.

"It is estimated that a “white” LED lamp is at least 5 times more powerful in influencing circadian physiology than a high pressure sodium light based on melatonin suppression. Recent large surveys found that brighter residential nighttime lighting is associated with reduced sleep time, dissatisfaction with sleep quality, nighttime awakenings, excessive sleepiness, impaired daytime functioning, and obesity. Thus, white LED street lighting patterns also could contribute to the risk of chronic disease in the populations of cities in which they have been installed. Measurements at street level from white LED street lamps are needed to more accurately assess the potential circadian impact of evening/nighttime exposure to these lights."

mtalantikite3• 10 years ago

I had LEDs installed in the streetlight in front of my apartment in Brooklyn a few months ago and my living room is now awash with this light. It's terrible. I noticed my sleep time pushed further and further back and I've resorted to supplementing melatonin regularly so that I can fall asleep earlier than 2 am. I've complained to the city and have considered moving since I don't think NYC will swap ours back.

keenerd8• 10 years ago

Please, put in blinds. If you have blinds, put in curtains to catch the light that spills around the blinds. If too much light goes through the blinds, upgrade to window shades. If that isn't enough (or you don't want to spend any money on interior decorating), get an eyemask. If $2 for an eyemask is too much, drape a t-shirt over your eyes.

Moving is a comically inappropriate response.

rbanffy• 10 years ago

If moving becomes a common response, we can use street lighting to fight gentrification. Don't discourage it.

mtalantikite3• 10 years ago

I don't find it unreasonable to want to have my curtains and windows open after sundown.

My bedroom is at the back of the house and feels like a cave, as is common for NYC bedrooms, so it's not the light in my eyes that is the issue. Having a delayed melatonin release due to the light is more my concern.

ocschwar• 10 years ago

Given that white LEDs rely on blue LED components, and blue LEDs are the most expensive and most delicate parts in these lights, one would think lowering the blue content should be a no brainer. More comfortable and cheaper all around.

ivan_ah• 10 years ago

On a related topic, y'all should check `f.lux` for removing the blue hues from your monitor after 9pm: https://justgetflux.com/

ChuckMcM• 10 years ago

It is a confusing story, and not well supported by actual facts or studies. So I wonder about these things, who has it in for street lights? Crooks obviously it makes their life harder (and it mentions in the article that police are getting better witness descriptions under LED lights). And presumably the folks who made the old Mercury Vapor lights. Which happen to have about 1/10th the cost to make as LED lights but seem to sell for the same amount, so perhaps their margins are getting squeezed uncomfortably. Power companies of course, who could depend on the electricity load coming from inefficient street lights finding that one of their biggest consumer at their lowest utilization time is cutting their power requirements by 33% or more. That has to hurt you really don't want to turn off base load during the night. And of course people who liked the look of their street before and now are sad because it looks different[1].

[1] When people switched from coal fireplaces to gas heat a common complaint was that it didn't smell like home any more.

Animats• 10 years ago

I've had it with "warm, yellow" street lights. Redwood City, CA standardized on low-pressure sodium lamps decades ago. Other than the Golden Gate Bridge, almost nobody uses those deep yellow lamps any more. (The Golden Gate Bridge switched to high-pressure sodium in the 1970s, and LEDs recently, but put in amber lenses to maintain the old color.) Redwood City is finally going LED, and streets look much brighter.

wamatt• 10 years ago

FTA '“Nobody says don’t watch television or use your computer after 9 p.m. because of blue lights,” he said.'

Yeah about that. Seems we have a ways to go still wrt nocturnal blue light usage and health advocacy.

Philip_with1L• 10 years ago

I remember reading here in Pittsburgh that the new street lights could be addressed individually or as groups and have their white points adjusted. I've never seen this in action and I haven't researched it further. But if they could be adjusted to be less blue, we'd still benefit from the energy savings.

tracker1• 10 years ago

Wouldn't filters or rough refraction surface help offset the risks? Of course, I kind of feel that in climates with snowfall, the bulbs that generate heat are probably better for keeping said snow from building on the street lamps/lights.

Some cities are taking another look at LED lighting after AMA warning

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