Ottawa installing 58,000 LED streetlights, despite health warning

Ottawa is gradually becominghome to some 58,000 LED streetlights even asa recent health warning has some U.S. cities rethinking the energy-saving strategy.

In 2015, thecity entered into a partnership with Energy Ottawa, a subsidiary of Hydro Ottawa, to convert its oldsodium and metal halide lights to LEDs over a four-year period.

This summer, however, the American Medical Association issued a report warning that certain high-intensity LED lights can cause "discomfort and disability" and that brighter residential nighttime lighting is associated with poor sleep, obesityand impaired daytime functioning.

• LED traffic lights trouble in winter because they don't melt snow
• LED lights may impact bat populations, research shows

To get the white light associated with LEDs, designers mix yellow and blue light and that blue light can disrupt circadian rhythms in humans, according toRobert Dick, aphysics professor at the University of Ottawa and a long-time dark skies advocate.

"Life has evolved on earth for four billion years with the light and dark contrast. It's literally in our DNA," Dick toldCBC'sOttawa MorningTuesday.

"And once you disrupt that light once you add light in the nighttime that throws offour biochemistry. There's no winners in that."

The city says its new LED lights possess a number of benefits, including lower maintenance costs and better visibility for pedestrians, cyclists and drivers.

Listen to the entire interview with Robert Dick here.