6 ms·

> "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

> "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.

siegecraft 10y ago
Yes, but daylight only occurs during the day, hence the name.
- dingaling 10y ago
  > Yes, but daylight only occurs during the day, hence the name. 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.
  - cauterized 10y ago
    And for eons before that, the light we had at night was fire. That's long enough for us to evolve to be sensitive to blue light as a signal of daytime while having decreased curcadian sensitivity to light at lower color temperatures.
Dylan16807 10y ago
If you don't get tired at night, you don't sleep well, and sleep deprivation is much worse than being tired. 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.
- mullingitover 10y ago
  > Bright light, especially blue light makes your body react like it's daytime. 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.
  - Dylan16807 10y ago
    Even when it screws up those levels for hours after you get out of the car? 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.
- stephengillie 10y ago
  Please quote a study verifying this with at least a few hundred people, if not a few thousand. The reason we think it's hogwash is because supporting studies involve only single-digit groups. The study I performed, involving 3 males and 2 females between 18-34, found blue light does not impact ability to sleep.
  - phee 10y ago
    Not to diminish your study, but a simple "blue light circadian sleep" search in google scholar suggests a pretty mature understanding of the phenomenon, both at biochemical and phisiological level. My little study shows that after covering with black electrical tape each and every blue and white status led around the house everyone involved sleeps better.
patrickmn 10y ago
Related: https://justgetflux.com/research.html https://justgetflux.com/research.html
- tacos 10y ago
  Perhaps not the most neutral source for information. I found their summaries of paywalled articles to be a bit... misleading. They'll sell you Swarovski crystals and Himalayan salt lamps though.
  - stephengillie 10y ago
    They do provide abstracts, which is nice. From those, you can see how few subjects are used in these studies.
Bluestrike2 10y ago
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 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.
- DanBC 10y ago
  > 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.
cauterized 10y ago
Surely then we could use blue-white LEDs on highways an in commercial areas where most of the driving time is spent and warmer colors in residential areas that are just the last minute or two of the drive and are where people are trying to sleep?
- mullingitover 10y ago
  That seems like the right answer to me. I still think the streetlights make very little difference compared to the time that the average person spends looking at a screen, however. In my experience the only time I'm looking at streetlights are when I'm in a car, or walking to one. On the other hand I probably average three hours a night looking at a screen.
  - cauterized 10y ago
    For those of us who have LED streetlights right outside our bedroom windows, it makes an enormous difference relative to screens, most of which these days you can at least put into an after-sunset mode even if you don't just voluntarily turn them off. The streetlights are on all night and they don't have an off switch.

siegecraft 10y ago

Yes, but daylight only occurs during the day, hence the name.

dingaling 10y ago
> Yes, but daylight only occurs during the day, hence the name. 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.
- cauterized 10y ago
  And for eons before that, the light we had at night was fire. That's long enough for us to evolve to be sensitive to blue light as a signal of daytime while having decreased curcadian sensitivity to light at lower color temperatures.

Dylan16807 10y ago

If you don't get tired at night, you don't sleep well, and sleep deprivation is much worse than being tired. 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.

mullingitover 10y ago
> Bright light, especially blue light makes your body react like it's daytime. 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.
- Dylan16807 10y ago
  Even when it screws up those levels for hours after you get out of the car? 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.
stephengillie 10y ago
Please quote a study verifying this with at least a few hundred people, if not a few thousand. The reason we think it's hogwash is because supporting studies involve only single-digit groups. The study I performed, involving 3 males and 2 females between 18-34, found blue light does not impact ability to sleep.
- phee 10y ago
  Not to diminish your study, but a simple "blue light circadian sleep" search in google scholar suggests a pretty mature understanding of the phenomenon, both at biochemical and phisiological level. My little study shows that after covering with black electrical tape each and every blue and white status led around the house everyone involved sleeps better.

patrickmn 10y ago

Related: https://justgetflux.com/research.html https://justgetflux.com/research.html

tacos 10y ago
Perhaps not the most neutral source for information. I found their summaries of paywalled articles to be a bit... misleading. They'll sell you Swarovski crystals and Himalayan salt lamps though.
- stephengillie 10y ago
  They do provide abstracts, which is nice. From those, you can see how few subjects are used in these studies.

Bluestrike2 10y ago

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 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.

DanBC 10y ago
> 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.

cauterized 10y ago

Surely then we could use blue-white LEDs on highways an in commercial areas where most of the driving time is spent and warmer colors in residential areas that are just the last minute or two of the drive and are where people are trying to sleep?

mullingitover 10y ago
That seems like the right answer to me. I still think the streetlights make very little difference compared to the time that the average person spends looking at a screen, however. In my experience the only time I'm looking at streetlights are when I'm in a car, or walking to one. On the other hand I probably average three hours a night looking at a screen.
- cauterized 10y ago
  For those of us who have LED streetlights right outside our bedroom windows, it makes an enormous difference relative to screens, most of which these days you can at least put into an after-sunset mode even if you don't just voluntarily turn them off. The streetlights are on all night and they don't have an off switch.