BRIGHT NIGHTS, UNWITTING CITIES
Montreal is not the only metropolis replacing its outdoor lighting with efficient white LEDs. They come with the promise of big savings. But as nights get lighter, scientists say the dark, starry sky isn’t the only loss. People’s health is also at greater
Cities are getting brighter every year.
Since Thomas Edison flipped the switch in 1879, electrical light has saved lives in hospitals, extended hours of play in parks, given us picturesque city skylines and allowed New York to become the city that never sleeps.
But while the importance of artificial light is remarkable, the value of darkness is much less obvious.
Light pollution now blocks out the stars at night in many cities, and a growing number of citydwellers have never seen the Milky Way. Canada’s biggest observatory, in Toronto, closed in 2008 because astronomers could no longer see a dark, starry sky.
Now scientists, environmentalists and some municipal politicians are sounding the alarm about light pollution for another reason: changes in human health and the ecosystem.
Light pollution has been linked to an increased risk of sleep disorders, cancers, diabetes, mental problems and obesity. It also has serious sometimes deadly consequences for animals who are being confused by artificial light at night.
And it is the energy- efficient LED lights that are a particular cause for concern.
Montreal, l i ke many ci t i es around the world, is converting its outdoor lighting systems to white LED bulbs because of their low- energy consumption and significant cost savings. LED bulbs use 50- to 70- per- cent less energy than traditional bulbs, according to a 2012 report by The Climate Group, an international non- profit organization that promotes clean and renewable energy.
Montreal plans to swap out 110,000 lights across the city at a cost of $ 110 million. In return, it hopes to cut its electricity bill by half and reduce maintenance costs by 55 per cent. Over 20 years, the goal is to save $ 278 million.
Gatineau has been migrating to white LED lights since 2007, and Ottawa is converting all of its outdoor sodium lights to white LED lights by 2020. Sodium lights are more expensive than LED lights, but they contain very little or none of the blue colour of white LED lights.
LED technology was developed in the 1960s, which makes it still relatively young. But it has evolved much more rapidly than any other lighting technology. Fluorescent technology has doubled in efficiency since 1950. LED technology has increased its efficiency, meaning its visible light produced, by 1,000 per cent in just 15 years.
But scientists agree there are a growing number of issues associated with LED lighting.
The technology initially produced a red light. As new materials became available, new light colours and wavelengths were created to finally achieve a bluish- white light.
It is this blue light that scientists say is the problem.
In white LED bulbs, a phosphor coating on one part of the bulb, the emitter, absorbs some of the blue rays to produce warmer yellow light through fluorescence. The combination of that yellow emission with remaining blue emission appears white to the eye.
“We aren’t against all LEDs,” says Martin Aubé, an astrophysics professor and researcher at CÉGEP de Sherbrooke. “Only against the white ones, because they contain that bluish colour.” White LEDs come in a range of whites — warm, cool, bright — but all of them contain the blue that increases light pollution and has been linked to health issues.
“Using white LED lights increases light pollution by three times, which means 300 per cent more light pollution,” says Aubé. “If it continues in this direction, it is crystal clear that not only we won’t see the starry sky, but our health and ecosystem will pay the price.”
So, if anyone thinks Montreal is going reduce its light pollution by adopting white LEDs, they’re wrong, says Sébastien Giguère, scientific coordinator at the MontMégantic International Dark- Sky Reserve. The white LED 4000k lights that will be used to light up Montreal’s streets will increase light pollution by at least 250- percent more than the bulbs they are replacing, he says.
Never mind that “the proportion of young people who have seen the Milky Way is in a constant decrease,” as he says.
Light pollution in Montreal is at a very important turning point because of those lights, says James D. Lowenthal, professor at the astronomy department of Smith College in Northampton, Mass., who is working at McGill Space Institute until July.
"It is so important to get it right.,” Lowenthal warns.
The average person is now exposed to artificial light from 17 to 20 hours a day, seven hours more than the average exposure to natural daylight, says Johanne Roby, professor of chemistry at CÉGEP de Sherbrooke and an organizing member of Artificial Light at Night, a series of worldwide conferences dedicated to examining artificial light at night.
"Our body is not able to distinguish daytime from nighttime anymore and … can’t rest. It’s just getting worse and worse, and it’s starting to be scary,” she says.
All around us, we’re being exposed to more artificial light than ever, and the increasing efficiency of that light is creating harmful consequences.
The U. S. National Institutes of Health’s National Library of Medicine and the American Medical Association have published research that says this exposure heightens the risk of sleep disorders, diabetes, obesity, even cancer.
Light pollution is growing at an average rate of six per cent a year in North America.
And it is changing our environment into one for which we have not evolved, says Robert Dick, chair of the Royal Astronomical Society of Canada’s Light- Pollution Abatement Committee.
In 1987, the University of Connecticut cancer epidemiology professor Richard Stevens suggested that breast cancer could be linked with nighttime light exposure. He blamed exposure to artificial light for the suppression of melatonin production, a hormone that helps protect against tumour growth.
Melatonin also has antioxidant properties, induces sleep, boosts the immune system, lowers cholesterol, and helps the functioning of the thyroid, pancreas, ovaries, testes and adrenal glands.
“Melatonin is the key hormone to reset our body,” says Roby, the chemistry professor in Sherbrooke.
In 2012, the American Medical Association pointed to Stevens’s report when it recommended the development of new lighting technologies.
While blue shortwave illumination has been linked to the suppression of melatonin, no policies have been implemented in Montreal to restrict the use of white LED lights. Other cities in Canada have adopted policies for outdoor lighting. Sherbrooke will only allow white LED lights in certain areas of the city, like gas stations and sport fields.
The Bureau de normalisation du Québec, which sets environmental and industrial standards across the province, is developing standards for outdoor lighting. Public consultations on proposed standards wrapped up at the end of July, and guidelines will be developed over the coming year.
Aubé, t he astrophysics r esearcher in Sherbrooke, says the proposed standards will have some positive impact on light pollution, but he says they don’t go far enough. “They are proposing a … zoning system,” he says. “The policy is very strict around the Mont- Mégantic Dark Sky Reserve, for example, but is looser in cities such as Montreal.”
“My colleagues and I strongly believe that if artificial lighting is bad in one place, it’s also bad in the other one.”
While the proposed guidelines suggest changing the orientation and intensity of lights to curb light pollution, the use of white LED bulbs would not be restricted.
“We fear that the light pollution improvements from those suggestions are cancelled ( out) because cities are still using white LED lights,” Giguère says.
For two amateur astronomers who live in Sherbrooke, the proposed guideline simply does not go far enough. Manon Bouchard and Christine Renaud are petitioning to stop the proliferation of LED lights and what they see as the over- lighting of cities.
“Maybe we will spend more money if we buy sodium lights instead of white LED lights, for example, but we will save on humans’ health and on cancer treatments’ costs,” says Renaud. “Isn’t that logical?”
The cost of “lighting the sky ” is estimated at $ 45 million a year in Quebec, according to the ASTRO - Lab of Mont- Mégantic National Park.
“What’s so frustrating about light pollution is that the problem is very solvable, compared to air pollution, which takes decades to solve,” says Cheryl Ann Bishop, communication and public affairs director at the International Dark- Sky Association, a non- profit organization based in Tucson, Arizona. “It’s only a matter of putting on lights responsibly.”
Lowenthal says a significant number of places in Montreal could be better lit at night.
“Old Montreal is a beautiful place during the day, but it’s ugly at night because it is illuminated terribly," he says.
“Even George- Étienne Cartier monument on Parc Ave. is awfully lighted at night by a glaring spotlight pointing towards to sky.”
Montreal plans to orient its outdoor lights downward — a great improvement — but the new lights will contain 30- per- cent blue, a disappointment to Giguère: “To be recognized as dark- sky friendly, according to the International Dark- Sky Association, a light has to contain 20- per- cent- or- less blue colour."
The lure of cost savings will continue to add to the problem, Aubé predicts.
“On one side, scientists are telling people that light pollution and especially LED lights are bad for their health, and on the other side, LED - light companies are selling their products by saying that they are energy- efficient. The industry is very convincing on the question of energy efficiency."
But, he adds: "Maybe cities are making a huge mistake.”