The City of Montreal will replace 132,000 streetlights with 3000K LED lights, which emit a warmer glow than the lights it had planned to install. The change was in response to citizen’s concerns about the health hazards and light pollution.
Whe the city first announced the plan to replace the current high-pressure sodium lights with more energy-efficient LED lighting, some people expressed fears the 4000K lights it was planning to use would be too disruptive.
The 4000K lights emit a blue-rich light, closer to simulating daylight than the 3000K LED lights do.
“After taking note of all the information, notably on the issues of security, light, atmosphere and public health, we chose to move forward with a less intense luminosity,” Montreal Mayor Denis Coderre said in a statement.
“We want to make sure that in crossroads, in parks, that people will have the capacity to feel secure,” he said.
The American Medical Association (AMA) established guidelines in June 2016, and cautioned against the use of LED lights which “emit a large amount of blue light that appears white to the naked eye and create worse nighttime glare than conventional lighting.”
“Discomfort and disability from intense, blue-rich LED lighting can decrease visual acuity and safety, resulting in concerns and creating a road hazard,” the AMA said.
According to the AMA, the blue-rich LED night-time lighting suppresses melatonin and “is associated with reduced sleep times, dissatisfaction with sleep quality, excessive sleepiness, impaired daytime functioning and obesity.”
The reason, according to the AMA, is the amount of blue light emitted by LED lights with a higher Kelvin (K) value.
Several cities have switched to the higher K-value lights, and have received varying response from the public.
New York City optded for lower K-value LED lights after a growing number of complaints.
In Sherbrooke, Quebec,the city’s proximity to the Mont Mégantic astronomical observatory led to concerns about light pollution, and it chose much dimmer 1800K LED lights.
Toronto will not be changing the 4000K lights now over the main arteries, and in Seattle, Washington, they’ve chosen extremely bright 4100K lights.