Live data from Hacker News

Doctors issue warning about effects of LED streetlights on health

theconversation.com

21–30 of 89 posts

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

#21

Earlier quoted context omitted.

A filter to block out a bit of the excess blue light? This would reduce the effectiveness of the light output though, unless you amped up the output to raise all of the colors and then selectively suppressed the blue to help balance it out. Then this would require extra energy, which defeats the purpose of using LEDs to save energy.

You can just use a different color of LED. Honestly people in Seattle, where these LED lamps were first piloted, have been raising these concerns for at least 4 years. This is the product of some combination of bad design, a lack of user-centered thinking at the utilities, and less than ideal incentives. For example, daylight led's were touted as making it easier to identify cars involved in criminal activity because…

One of the many hats that I wear at my day job is optics designer. An issue is that the white LED is a particular thing. It's a blue LED coated with a phosphor that absorbs some of the blue light, re-emits it at a broad range of longer wavelengths, while also passing some of the remaining blue light through.

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.

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

#22

> "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.

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?

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.

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

#24

Earlier quoted context omitted.

You can just use a different color of LED. Honestly people in Seattle, where these LED lamps were first piloted, have been raising these concerns for at least 4 years. This is the product of some combination of bad design, a lack of user-centered thinking at the utilities, and less than ideal incentives. For example, daylight led's were touted as making it easier to identify cars involved in criminal activity because…

One of the many hats that I wear at my day job is optics designer. An issue is that the white LED is a particular thing. It's a blue LED coated with a phosphor that absorbs some of the blue light, re-emits it at a broad range of longer wavelengths, while also passing some of the remaining blue light through. The blue is special -- 473 nanometers -- due to the solid state physics of the semiconductor. There is indeed…

Is it currently feasible to make LED's at that brightness that are closer to the old yellow-orange lamps?

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

#25

Earlier quoted context omitted.

A filter to block out a bit of the excess blue light? This would reduce the effectiveness of the light output though, unless you amped up the output to raise all of the colors and then selectively suppressed the blue to help balance it out. Then this would require extra energy, which defeats the purpose of using LEDs to save energy.

You can just use a different color of LED. Honestly people in Seattle, where these LED lamps were first piloted, have been raising these concerns for at least 4 years. This is the product of some combination of bad design, a lack of user-centered thinking at the utilities, and less than ideal incentives. For example, daylight led's were touted as making it easier to identify cars involved in criminal activity because…

Really? Who complains about the new lights?

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.

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

#26

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.

They are a tad bit intense but they really save your bacon when there are deer in the ditches. I do wish there was a middle ground.

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

#27
Not my area of expertise by any means, but maybe quantum dots could be used to filter only a small sliver of the visible spectrum produced by streetlights. Maybe there could be very-nearly transparent foils that you could overlay over your windows that would block just that light.

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

#28

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 literally LOL @ "white dwarf". I absolutely agree, but, I have to admit... I have those lights :/

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.

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

#29

What does the AMA know about LEDs and health? There's nothing in this article about why they made these recommendations. And the article compares LED lighting to 'before electricity', instead of to for instance existing sodium lamps? It is an opportune moment to make the recommendation, since folks are converting to LED so rapidly.

It's sort of the AMA's central mandate to know about things that affect health.
Post reply on HN