Concerns about LED street lights
The city is proceeding with installing LED street lights, as came up here on the blog recently. The question what colour to use has been discussed – the Coderre administration, which started this, wanted 4000K, which is relatively cold and blue, but wavered over colours varying from 1800K to 3000K in some cases. The problem is that studies show that daylight at night confuses the hell out of our bodies and brains, and is also no good for plants and animals. Experts are contesting the decisions being made.
Mr.Chinaski 11:48 on 2020-01-23 Permalink
We’re falling into “Wifi causes cancer” territory here…
Blork 11:59 on 2020-01-23 Permalink
No we are not. Plenty of research into this, and blue light at night can be very weird and can affect people and animals. From an article at engineering.com:
First of all, there’s nothing inherently dangerous about any light in the visible spectrum, as long as the intensity isn’t too high. (Sunlight is safe, but don’t look directly at the sun.) The issues with artificial lighting have more to do with affecting an organism’s circadian rhythms – the natural cycles that tell our bodies when to sleep. Light that leans toward the blue end of the spectrum is similar to the natural daylight that we’d see around midday. That’s the time when we’re supposed to be most productive, so our bodies react to that light by being alert. Nighttime exposure, however, can lead to sleep disorders, and therein lies the health concern. (It should be noted that the same concern exists for computer, tablet, and smartphone displays. Turn off your devices at night and get some sleep.)
https://www.engineering.com/ElectronicsDesign/ElectronicsDesignArticles/ArticleID/14607/Are-LED-Lights-Bad-for-Your-Health.aspx
Charles 15:07 on 2020-01-23 Permalink
Let’s put things into perspective.
~2400-3000K is what we’ve been used to in the past from incandescent lights in our homes and simulated in warm fluorescent bulbs. “Cool white” fluorescents are closer to ~5000K.
~5500K is midday sunlight, no clouds—with a cloud cover or open shade is cooler than that, up to ~6500K.
6500K (“D65”) is our computers and mobile devices. This looks “neutral white” to most people, not even blue.
So let’s not freak out about 4000K, which is still quite warmer than daylight. To speak about that as “blue” light is ridiculous.
Sodium-vapor lamps from older streetlights is warmer, but it’s also not a full spectrum and is actually quite unnaturally nauseating. I’ll take 4000K LED over sodium-vapor immediately please, thanks.
Ian 15:47 on 2020-01-23 Permalink
I just hope they can figure out the brightness issue – on some streets like Dr. Penfield it’s quite difficult to see the road surface at night with the new lights.
Joey 16:52 on 2020-01-23 Permalink
As much as I miss the orange snow, I think Ian makes the crucial point here – the new streetlights diffuse light in a way that’s less effective than the old ones. The contrast of lights that seem brighter in their immediate surroundings with the darker areas not nearby (i.e., street level) makes it harder for pedestrians, cyclists and drivers to see what’s right around them – seeing around corners, sensing others in the roadway, etc., is more difficult than it used to be. Arguing about how blue the light is, while intriguing, is a distraction from this more fundamental issue: the city has gone and made public safe harder to navigate.
Raymond Lutz 17:04 on 2020-01-23 Permalink
@Joey. Ah! Maybe old sodium lamps don’t degrade our visual purple as much as white fucking-blue lights?
“To speak about 4000K as “blue” light is ridiculous.” Hmm… 4000K leds DOES have 420–440 nm wavelengths https://www.ledsmagazine.com/smart-lighting-iot/white-point-tuning/article/16695938/light-pollution-depends-on-the-light-source-cct-magazine
JaneyB 20:39 on 2020-01-23 Permalink
Blue light is absolutely one of the most important public health issues of our time. The evidence of elevated effects on cancer risk (eg night shift work) is strong enough that in Europe there is financial compensation for the risk. The problematic effects on wildlife are increasingly disturbing (re:hibernation, reproduction, sex ratios of offspring). Technically, even all-red light above 10 lux has effects on lab animals. Circadian research won at least one recent Nobel prize in medicine. We already know about Seasonal Affective Disorder. Bipolar disorder is strongly affected by time zone changes etc, etc. This is not a chemtrails thing at all. Living beings are exquisitely sensitive to blue light (think: sunlight). Decades from now people will look back at our recklessness around light like we think today about DDT and paraquat.
Dhomas 06:52 on 2020-01-24 Permalink
Other than all the blue light issue (which is definitely important), there is also a road safety issue, as Ian mentioned. I usually don’t drive much at night, but I needed to yesterday and it was quite difficult to see the roadway under the new lights. I even double checked to see if I’d not turned on my headlights. The new lights simply don’t seem to illuminate enough.
EdT 19:10 on 2020-01-31 Permalink
There will always be non technical whiners in every city and society. Only the Coderre administration like the Drapeau administration could have gone through with this project with an iron-fist which is a no-brainer decision to start with !