In October, FortisAlberta began converting the majority of the city’s streetlights to LED technology free of charge.
The conversion of 5,800 streetlights from high-pressure sodium is estimated to save the city about 2.3 million kWh/year of electricity, which is the greenhouse-gas equivalent to taking 317 cars off the road or planting 68,072 trees annually.
Despite being good for the environment and municipal coffers, the new LED lights could be cause for concern when it comes to residents’ health and safety.
In September, the American Medical Association put out an official policy statement outlining optimal design and engineering features for LED street-lighting in an effort to minimize the detrimental effects of blue light.
According to the AMA, high-intensity LED lighting creates worse nighttime glare than conventional lighting due to the large amount of blue light emitted.
Blue light, which can appear white to the human eye, scatters when it hits the retina causing what is called disability glare – a temporary visual impairment that decreases contrast and makes nighttime driving dangerous.
AMA is encouraging communities and hydro companies to use the lowest colour temperature possible (3000K) to reduce glare when retrofitting to LED lighting.
But it’s not just drivers that can be affected.
Studies have shown that bright residential nighttime lighting can be associated with reduced sleep times, poor sleep quality, excessive sleepiness, impaired daytime functioning and obesity.
Using satellite data, a recently published study out of Stanford University in California estimated that white LED light is five times more powerful in influencing circadian physiology than a high pressure sodium light, due the suppression of melatonin – the hormone that controls sleep and wakefulness.
While the AMA report raised questions about colour temperatures in other Canadian jurisdictions like Toronto and Surrey, Gilles Prefontaine, general manager of development services division indicated the city trusted FortisAlberta’s expertise in the matter.
FortisAlberta plans to use the first generation 4000K lights, which emit 29 per cent of its spectrum as blue light, when converting St. Albert’s streetlights, rather than the 3000K units, which have a 21 per cent blue light emission and are only three per cent less energy efficient.
St. Albert resident Dick Clarke, who brought the health and safety risks to council’s attention last month, was not satisfied with the city’s response.
“It doesn’t seem like they’re doing their due diligence with the medical issue raised,” he said.
A spokesperson for the utility company indicated that 4000K LED lighting was industry standard set by the Illuminating Engineering Society of North America (IESNA).
IESNA questioned the findings of report upon which the AMA based its recommendation, as did the U.S. Department of Energy.
“When considering the effects of light at night and to put it into perspective, we receive much more exposure through our indoor lighting,” said Alana Antonelli, manager of corporate communications for FortisAlberta.
“The quantity of light emitted by streetlights (and that which we are exposed to) is many times lower than that emitted by typical indoor lighting, TVs, tablets or PC screens,” she continued, “especially when we consider how much time we spend in front of our devices and with the lights on inside our homes.”
