(Sherbrooke) Wanting to reduce the light pollution that makes it difficult to see the stars, professors-researchers at the Cégep de Sherbrooke have launched an amber light bulb so that citizens can replace their outdoor lighting that is too white.
Posted at 5:00 a.m.
In the darkness of her windowless laboratory, Johanne Roby lights two light-emitting diode (LED) bulbs placed side by side. The contrast is striking. The one on the left, sold in hardware stores, casts a cold, very raw white light. The one on the right, designed by his lab, emits a soft orange-yellow glow.
The spectrometer of Mme Roby provides us with additional information: the white light bulb emits much more blue light. “Blue light diffuses much more in the atmosphere, that’s why it creates more light pollution and we see less of the starry sky,” sums up the teacher in the chemistry department at Cégep de Sherbrooke.
PHOTO MAXIME PICARD, LA TRIBUNE
Johanne Roby, teacher in the chemistry department at Cégep de Sherbrooke
Like several municipalities in the Eastern Townships, Sherbrooke has adopted regulations on the control of exterior lighting, in support of the Mont-Mégantic International Dark Sky Reserve. This spangled sky, Mme Roby and his colleague Martin Aubé, a teacher in the physics department, also want to make it accessible in Sherbrooke, by creating a “starry night oasis” above Mont-Bellevue Park. But to convince neighborhood residents to reduce the light pollution generated by their outdoor lighting, they had to be offered an alternative.
“Warm and enveloping”
In collaboration with CEGEP and university students, the two researchers developed their low blue light LED bulb, and led a crowdfunding campaign to have it made and donated in a neighborhood near the park. Of the hundred or so doors they knocked on, nearly 80 residents agreed to install them, replacing more than 150 exterior bulbs.
PHOTO MAXIME PICARD, LA TRIBUNE
Low blue light LED bulb
Building on this first “Nighttime Integrity District,” the Oasis Project began rolling out its bulbs to the general public last month. With only two points of sale in Sherbrooke, about 350 have gone in a few weeks – the organization hopes to be able to offer them online.
The bulb, guaranteed for five years, retails for $10. DH Éclairage, a local company specializing in LED conversions to reduce energy consumption, was responsible for having it manufactured. “The objective here is not at all commercial, it is because we adhere deeply to what they are trying to put in place”, underlines the general manager of DH, Dominique Morin.
-
PHOTO MAXIME PICARD, LA TRIBUNE
Blue light emitted by a conventional 5000K LED bulb
-
PHOTO MAXIME PICARD, LA TRIBUNE
Low amount of blue light emitted by the 1500 K LED bulb developed by Johanne Roby’s team
1/2
The color temperatures of the bulbs are usually indicated on the packaging by a number followed by a “K” (for kelvins). The lower it is, the more yellow the light will be. This is why the Oasis 1500K bulb contrasts so much with the 5000K, 3000K or 2700K bulbs commonly installed around homes.
“When you compare, the difference is a bit shocking. I hesitated a lot before having the 1500 K made because I was wondering if people were going to join,” says M.me Roby, who coordinates the project. The reaction of the first residents consulted, who had the impression of “being part of a change”, reassured her.
PHOTO PROVIDED BY JOHANNE ROBY
The first nocturnal integrity district, in Sherbrooke, where the Starry Night Oasis project provided residents with amber light bulbs
“When you sit down for the evening in your yard, your eyes get used to it and it’s very pleasant, it’s warm and enveloping. »
Disrupted biological clock
The stars are not the only goal. “Our biological clock is regulated, among other things, by blue light. We are in the process of disrupting it, ”said Mme Roby, evoking the bluish light of electronic devices, but also that of outdoor lighting that often seeps into bedrooms.
Blue light is increasingly linked to the development of hormone-dependent cancers – breast and prostate cancer, and colorectal cancer.
Johanne Roby, teacher in the chemistry department at Cégep de Sherbrooke
Light pollution also affects wildlife, adds Mme Roby citing bats, frogs and the northern dusky salamander. This salamander classified as “likely to be designated a threatened or vulnerable species” by Quebec is present in Mont-Bellevue Park.
“We want to protect her! In addition, she is so beautiful with her prickly back: I would like her to become our emblem because she has a starry sky on her back. »
8 kilometer “Corridor of Darkness”
Oasis is also setting up an 8-kilometre “corridor of darkness” to allow animals to move between Mont-Bellevue Park and the Magog River. The route will be accompanied by interpretation panels. “It’s a small corridor, but we want to demonstrate it to raise awareness with something concrete. »
Awareness will therefore continue around the park, with residents, but also businesses, who will be able to apply for the “Friend of the starry sky” certification, awarded by the Mont-Mégantic International Dark Sky Reserve.
Oasis researchers have also characterized more than 300 bulb models (including their blue light levels) in a database from which they plan to publish a statistical analysis in a peer-reviewed scientific publication.
They also mapped the light pollution of Paris, Lyon and Rennes, data that they want to cross with those of the vast Constances epidemiological cohort, bringing together 200,000 French people.
Learn more
-
- 2%
- Rate of blue light emitted by the Starry Night Oasis 1500K LED bulb. That’s far less than the LEDs commonly used outside homes—lighting from a 5000K can contain up to 38%.
Source: Starry Night Oasis Project