LED Lights Installed In Halifax Rejected In Toronto, Calgary, Phoenix and Elsewhere

As of April 2017, many residents in neighborhoods on the Halifax peninsula are seeing scenes outside their bedroom windows similar to what appears below.

LED light pollution lighting up bedrooms, disrupting sleep

LED light pollution lighting up bedrooms, disrupting sleep

Daytime conditions at night are driven by two issues. The first is that 4000K LED lights are being used across the Halifax Peninsula. These lights produce short wavelength, high energy light which is uncomfortable for the eye. The second is that --- as shown in the image above --- the hoods in which bulbs sit allow tremendous amounts of light to spill out horizontally in through windows of adjacent homes. These kinds of LED lights (i.e., 4000K with hoods that promote light pollution) have been rejected in several other cities as described further below.

Over the last 9-12 months, the press has reported on studies regarding the impact to human health posed by 4000K and 5000K LED lights.  In June 2016, the American Medical Association issued the following statement as part of a broader set of guidelines of direct relevance to municipalities:

High-intensity LED lighting designs 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.

In addition to its impact on drivers, blue-rich LED streetlights operate at a wavelength that most adversely suppresses melatonin during night. It is estimated that white LED lamps have five times greater impact on circadian sleep rhythms than conventional street lamps. Recent large surveys found that brighter residential nighttime lighting is associated with reduced sleep times, dissatisfaction with sleep quality, excessive sleepiness, impaired daytime functioning, and obesity.

Source: AMA Adopts Guidance to Reduce Harm from High Intensity Street Lights

In June 2016, CNN published the following:

The AMA's (American Medical Association) statement recommends that outdoor lighting at night, particularly street lighting, should have a color temperature of no greater than 3000 Kelvin (K). Color temperature (CT) is a measure of the spectral content of light from a source; how much blue, green, yellow and red there is in it. A higher CT rating generally means greater blue content, and the whiter the light appears.

In cities where 4000K and 5000K LED lights have been used, residents have complained loudly. 

A white LED at CT 4000K or 5000K contains a high level of short-wavelength blue light; this has been the choice for a number of cities that have recently retrofitted their street lighting such as Seattle and New York.

But in the wake of these installations have been complaints about the harshness of these lights. An extreme example is the city of Davis, California, where the residents demanded a complete replacement of these high color temperature LED street lights.

Source: CNN: Doctors issue warning about LED streetlights

There are cities that are paying attention to both the science and the concerns of residents. The City of Toronto, ran a pilot program to evaluate LED lights prior to making wholesale changes across the city. In the fall of 2016, the City of Toronto released the following in a document titled Health Effects of LED Street Lights:

Toronto Public Health Briefing Note: Health Effects of LED Street Lighting:

On September 27, 2016 the Public Works and Infrastructure Committee requested the General Manager, Transportation Services to report to the Public Works and Infrastructure Committee, in consultation with Toronto Hydro, Toronto Public Health, and the Environment and Energy Division on possible benefits and risks to the public associated with the prevalent use of LED or other similar street lighting technologies in the Toronto street lighting system, and such report to include, but not be limited to:

a. consideration of the human health effects related to light colour temperature and intensity;
b. down lighting directional capabilities and light pollution effects;
c. contrast and traffic safety risks or benefits;
d. crime prevention factors; and
e. aesthetics.[i]


1. The City of Toronto to install LED streetlights with a colour temperature rating of 3000K or less with options for dimming lights during non-peak times and shielding to reduce glare.
2. Toronto Public Health to monitor the research related to the impacts of LED lighting on health.

Source: City of Toronto: Health Effects of LED Street Lights

In Calgary council discussed problems with 4000K and 5000K LED lights in advance of any permanent installation and is using LED lights that give off a yellow light vs. the blue/white light generated by 4000K LEDs. Additionally, the city is encouraging residents to call 311 if they notice light "trespassing" onto their property --– for instance if it's blasting through the window into a formerly dark bedroom. Calgary is very careful to use hoods on streetlights to explicitly "reduce the amount of “spilled” or wasted light, ensuring light is focused on roads and sidewalks, where it is most useful to drivers and pedestrians."  In other words, light from its LED lights is directed down and not allowed to spill out horizontally into windows. 

City of Calgary: Energy Efficient Lighting
Ottawa Metro: City of Calgary gives residents new LED lighting without the blue

Montreal has also made a decision to purchase 3000 Kelvin bulbs rather than 4000 Kelvin bulbs for essentially the same reasons as Toronto and Calgary.

CTV News: Goodbye lighting blues: Mayor opts for 'warmer' LED street lights
CBC News: Montreal opts for cooler LED lights after pushback over health risks

At this juncture, the hope is that HRM can address the following questions:

  1. Was a pilot executed to evaluate the impact of 4000K LED street lights on residents in the peninsula? If so, where was it conducted, who participated, and why was no information made publicly available?

    If there was a pilot, it's hard to imagine that 4000K were not rejected based on experience in others cities (e.g. Toronto, Calgary, NYC, Davis, etc.)

  2. Does HRM consider it reasonable that many (most?) residents do not want daylight conditions around the clock? Phoenix for example, is installing dimmer lights in response to widespread complaints. In Davis California, they did a complete recall as well.

Optimal outcome:

  1. HRM replaces 4000K bulbs with 3000K or lower per policy at Toronto, Calgary, Phoenix etc. (Per American Medical Association guidelines.)

  2. Hoods are installed to eliminate horizontal transmission of light as shown in two attached images (i.e. eliminate light pollution and direct light towards ground).

Councilman Waye Mason is asking for public input relating to this issue and has provided additional information in his article titled: LED Light Conversion, budget highlights, summer paving, more .  Please reach out to Waye and provide him with your thoughts.