Bright white LED streetlights may pose health risk

[Henry]

I remember seeing the then-new HPS lights go up in Chicago at a young age. Due to them being known for their installation in high-crime areas of large cities, I always made sure to stay as far away from them as possible, but inevitably, they were impossible to avoid on my way to Cubs games and such. Although I like seeing LED lights, the luminaires themselves are ass-ugly. It makes me wonder why they couldn't have saved the old cobraheads and simply retrofit those for LED use, like they did MV to HPS.

[MNHighwayMan]

I love that the city of Des Moines has been replacing their old lamps with the newer white LEDs. I always hated the orange hue the old lamps covered everything with at night.

[Mdcastle]

I've seen cobrahead and shoebox retrofits, generally you install a panel of LEDs just above the glass. But with replacing the ballast and not using the existing optics all that's salvageable is the fixture shell. And most HPS fixtures have been out in the elements for decades. Best just to pop a new fixture on.

[RobbieL2415]

Different light wavelengths can distort visual perception. White light is completely neutral.

[hotdogPi]

Why would artificial blue light be harmful if the amount you get from the sun is much more than any streetlight?

[vdeane]

For the same reason experts recommend against looking at computer screens, TVs, cell phones, and other devices shortly before going to bed.

[kalvado]

Why would artificial blue light be harmful if the amount you get from the sun is much more than any streetlight?

This is about blue light and sleep cycle. Theory is that blue light affects level of melathonin, which is associated with sleep cycle.
If you will, sun will also prevent you from falling asleep - but sunlight usually means it is not time to sleep anyway. Hence it is not a problem until you work night shift and need good curtains.
More here: https://www.scientificamerican.com/article/q-a-why-is-blue-light-before-bedtime-bad-for-sleep/

On a different note, UV in the sunlignt is potentially harmful in terms of skin cancer probability - and someone upstream recommended UV emitting lamps as solution for blue-induced sleep problems. What do you prefer, sleep problems or cancer?

[JoePCool14]

According to various researchers, scientists, and fun police, pretty much everything causes cancer/disease/negative consequences. So I'm just going to ignore that for now.

Putting that aside, I still prefer the old amber lights over the bright LEDs. They're great in certain places, but at other times they're just excessively harsh in certain locations. It's taken me a while to get used to driving the Jane Adams out west from Chicago since the rebuild. I will agree visability is great, but I still actually enjoy driving the section of US-20 around Rockford more. There's just something slightly more calming about it for me. Maybe it's just nostalgia.

Someone used the phrase happy medium earlier, and I think that describes what's best. Something whiter than the old, but not excessively harsh.

[US 89]

I’d favor a compromise of putting the brighter white LEDs on freeways and arterials and amber LEDs on neighborhood streets, assuming the cost is about the same. The harsh light color could keep drivers awake, and the fact that white LEDs contain enough blue to mess with the sleep cycle might be useful in protecting against drowsy driving on major roads. On minor streets and in neighborhoods, the amber lights give a warmer color that’s easier on the eyes, even if they make everything look orange. Most people aren’t going to want a lot of efficient harsh blue LED light shining into their homes every night.

[mgk920]

Some discussions that I read on this over the past couple of years also alluded to 4000-5000K LEDs messing with the sleep cycles of wildlife (ie, birds singing at the wrong times, etc).

Mike

[Mdcastle]

In the Twin Cities that's kind of what's happening: Mn/DOT and the cities are using the 4000K Cool White LEDs on the freeways and major streets. After using cool white in Bloomington and a few other south metro suburbs Xcel switched to warm white for the rest of their conversion project. Unfortunately the warm white of the GE Evolve fixture's they're using isn't very pleasing compared to the warm white of some other makers. To me "warm white" streetlights seem to be about halfway between 2700K soft / warm white and 3500K bright / neutral white, and the Evolves have an ugly pink cast.

I convinced my sister to use LEDs in her bedroom because she rarely remembers to turn them off. After trying abut a half dozen different lamps she settled on 3500K bright white. Interestingly enough there was a study done with a company that makes really high end "tunable" lamps that have both 2700K and 5000K primary emitters, as well as secondary RGB emitters. They found most people liked really blue light in the kitchen and about 3500K with a slight reddish cast in other areas.

[DaBigE]

According to various researchers, scientists, and fun police, pretty much everything causes cancer/disease/negative consequences. So I'm just going to ignore that for now.

Putting that aside, I still prefer the old amber lights over the bright LEDs. They're great in certain places, but at other times they're just excessively harsh in certain locations. It's taken me a while to get used to driving the Jane Adams out west from Chicago since the rebuild. I will agree visability is great, but I still actually enjoy driving the section of US-20 around Rockford more. There's just something slightly more calming about it for me. Maybe it's just nostalgia.

I hate to play the age card, but street lights weren't always amber/orange/peach.

[Mdcastle]

Yes, A lot of us still remember when cities were blue.

My first response to the blue light thing was to shake my head, since we've always had a lot of bluish lights around us. But when you look at the actual spectrum emitted as opposed to how we perceive it, mercury vapor and fluorescent tend to have a a spike centered around violet, rather than blue. That's the idea behind the Soraa LED, to emit a spectrum more like fluorescent and mercury vapor and less like traditional white LED.

[Plutonic Panda]

Yeah, I prefer the bright white LEDs. I believe the light pollution problem is being handled by better directing the light downwards rather than changing the color of the light. The light pollution issue from LEDs came to light(pun intended) awhile ago, but again, I believe they have found ways of dramatically reducing that effect by better directing the light downwards by using better covers and shields.

As for the cancer issue, give me a break. What doesn't cause cancer anymore?

[Plutonic Panda]

According to various researchers, scientists, and fun police, pretty much everything causes cancer/disease/negative consequences. So I'm just going to ignore that for now.

Putting that aside, I still prefer the old amber lights over the bright LEDs. They're great in certain places, but at other times they're just excessively harsh in certain locations. It's taken me a while to get used to driving the Jane Adams out west from Chicago since the rebuild. I will agree visability is great, but I still actually enjoy driving the section of US-20 around Rockford more. There's just something slightly more calming about it for me. Maybe it's just nostalgia.

I hate to play the age card, but street lights weren't always amber/orange/peach.

Interesting, I did not know that.

[TEG24601]

My city just went through the process of switching, including a public process.  We opted for a 3000K lamp, and they look great.  They have just a cone of light pointing down, and you can see quite well.  The color isn't likely going to cause much of a problem regardless, as there is practically no spillage anymore.  My bedroom used to have the amber hue of the streetlight on the adjacent corner, but now, nothing.

[WR of USA]

Right outside my bedroom there is a bright white LED street light. I would prefer a amber colored LED light, but it doesn't really bother my sleep that much. It doesn't have a huge effect this time of year anyways because sunset is so late in the evening.

[Duke87]

LEDs reduce light pollution, they're directional by nature, and never shoot light straight up into the sky, sodium vapor lights generally shoot light everywhere, including upwards and cause real light pollution.

Nnnn... LEDs reduce ambient light pollution. That does not mean they don't have problems with local light pollution. After all, while it is a narrower beam, it is a brighter beam, which makes it worse if it happens to be pointed at you.

Meanwhile the directional nature of LEDs can cause problems of its own. Plenty of jurisdictions which previously had their streets decently thoroughly lit have switched to LEDs and suddenly started having dark spots where they did not previously exist. One block near us now has basically no light on the sidewalk at night since the lights were changed to LEDs. The previous HPS fixtures lit up the sidewalk almost as well as the street.

On a similar note, my in-laws now complain that ever since the lights on their street were changed to LED, their front porch is now dark whereas the old streetlights lit it up at night. It's not the city's responsibility to light up their front porch, they were just getting it as a free service by accident when they were never entitled to it - but, you change anything, and people will complain. So it goes.


As for the prevalance of 5000K LEDs... it is worth noting that this is a natural consequence of how the technology works. The diodes themselves in LED lamps actually give off blue (like, legit pure blue) light, because diodes that emit at this wavelength are the cheapest to manufacture. The light is then made the desired color by placing a phosphor cap over the diode.
Since the light starts out blue, using phosphor to make it 5000K gets you a slightly less expensive to manufacture and slightly more efficient (in terms of lumens per watt) fixture than using more phosphor to get the color temperature down further.

[DaBigE]

Meanwhile the directional nature of LEDs can cause problems of its own. Plenty of jurisdictions which previously had their streets decently thoroughly lit have switched to LEDs and suddenly started having dark spots where they did not previously exist. One block near us now has basically no light on the sidewalk at night since the lights were changed to LEDs. The previous HPS fixtures lit up the sidewalk almost as well as the street.

Once again, it sounds like someone didn't do their homework when looking to retrofit. Photometric analyses don't require a lot of effort to produce, since the major manufacturers produce fixture files that can be directly imported into software like AGi32. You can tell nearly exactly where and what intensity light will be produced, given your pole spacing and mounting height. Changing a streetlight fixture is not as straight-forward as converting your table lamp bulb, but too many try to make it seem like it is. I've seen some really nice conversions which virtually eliminated any hot/dark spots encountered with HPS fixtures, and ending up with very uniform lighting with LEDs without having to move a single pole.

[index]

Interesting video weighing the pros and cons of LED/sodium.


This guy's channel also has a lot of other interesting videos.

https://www.youtube.com/watch?v=U1dMlVwUsrA


Another video.

[ErmineNotyours]

I used to work for the United States Postal Service for several Decembers and one six month summer vacation replacement period.  I had to work under orange sodium vapor lights, and I hated them.  Twice there were power outages at the air mail center where I worked, and the temporary lights, or working out in the dock, made things so much more pleasant and color balanced.

[jjakucyk]

Interesting video weighing the pros and cons of LED/sodium.

This guy's channel also has a lot of other interesting videos.

Another video.

Beat me to it.  He covers all the bases really well and came to basically the same conclusion I did, that LEDs are still the way to go, but at a roughly 3000K color temperature. 

[Zmapper]

In my new apartment I just swapped out an assortment of old incandescent/CFI/missing bulbs in the common areas for Walmart's Daylight (nominally 5000k, but reported to be closer to ~4500k) bulbs. In my bedroom, I'm testing the same bulbs for the ceiling light, accented with a 2700k bulb in a lamp for nighttime.

I personally like the more neutral white color from the 5000k bulbs after trying them; for daytime and early-evening use, 2700k bulbs have more of a de-energizing effect than I want after comparing both.

For public areas, I lean towards 4-5000k bulbs for commercial areas and arterial streets, and 25-3500k bulbs for residential areas.

[noelbotevera]

Here's my thoughts on lighting applications.

-Sodium vapor for neighborhood streets/light (don't know the proper term) commercial districts (example?)

-LEDs for freeways and major streets inside urban areas

-No lighting/minimal sodium vapor lighting in rural areas

For LEDs...not exactly a big fan of them. I have a computer in the same room as my bedroom, and whenever that's on, there's blinding blue light shining onto the bed, so it's hard to sleep without blocking it. To give an example of how bright, the small LEDs inside a wireless router still keep me up at night (ironically, I block the light using a Sandman comic book). I'm also accustomed to sodium vapor light, which is easy on the eyes and lights up the room, so I'm not complaining.

[cjk374]

I miss old fashioned light bulbs...and when streetlights were on a timer so they all came on, fully lit, at the same time.