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Conference illuminates the latest research on lighting

Recent gathering held in Toronto is part of the UN International Year of Light.


The conference room at the University of Toronto Faculty Club is handsomely appointed, right down – or up – to three sweeping circular brass chandeliers bisecting the room. Slender, sculpted metal branches culminate in three tiers of metal “candlesticks,” each tipped with a flame-shaped fluorescent bulb.

But on this day, the people sitting below the fancy fixtures were less concerned with aesthetics, than with the actual light they shed. “Awful! Absolutely awful,” Dr. Lorne Whitehead expostulates. “If you notice, everyone in the room looks kind of green.”

He was one of approximately 100 scientists, researchers and lighting experts from around the world at an October meeting in Toronto of the International Commission on Illumination, known by its French acronym CIE, an independent non-profit organization dedicated to the science of light. It has been recognized as the international authority and standardization body on lighting since its inception in 1913. The meeting coincides with the United Nations International Year of Light and Light-Based Technologies to raise global awareness about the role light plays in our daily lives, and in finding solutions to global challenges in energy, education, agriculture and health.

A professor in the department of physics and astronomy at the University of British Columbia, Dr. Whitehead is internationally known for developing brightness enhancement films, components commonly found in computer screens and televisions. “The original aim was to extend the battery life of computers because any light that gets sent out of the computer screen in directions other than the viewer is just wasted energy,” he says. “So it significantly increases the battery life of computers.”

He has also founded a number of companies, including TIR Systems, a UBC spin-off company purchased by Philips Lighting in 2007. He is currently focusing his research efforts on the colour quality of lighting.

“A lot of the pleasure of life comes from the appreciation of colour,” he says. “Just as nobody wants blurry vision, neither should we have to work under electric light bulbs that cause objects to appear to have incorrect colour. Most people want things to look their natural colour under electric lighting.”

However, that desire has been compromised since incandescent lights have now been widely replaced with compact fluorescent lights to save energy. “The colour isn’t as good [with compact fluorescent lights] but we were told we just have to live with that because we can’t afford good colour,” he says. As result, “many people hate them.”

But, adds Dr. Whitehead, the “incredibly good news today” is that with the advent of inexpensive light emitting diodes, or LED lighting, it’s possible to design light sources that are efficient and produce excellent colour. The goal, he says is to look for lighting that is as natural as possible, with a colour rendering index (CRI) above 90 on a scale that goes up to 100.

“Unfortunately, very few stores in Canada today sell LED replacement lamps with a CRI above 90,” he notes, “but there are several manufacturers in the U.S. that make them and they can be bought on the Internet.”

Meanwhile, researcher Marie Dumont at Université de Montréal, has a much different concern about lighting: its effect on sleep. Her research looks specifically at how police, pilots and other shift workers cope with sleep deprivation and exposure to light at night when their biological clocks are screaming “go to sleep!” A professor in the department of psychiatry, she says the scientific community has long known that they can adjust the circadian rhythm of night workers by exposing them to bright light at night.

“For astronauts it’s perfect because they cannot afford to have jet lag,” she says. “We can synchronize night workers for a night work schedule, but then when they return to the day schedule, because they are on a three-day work rotation, we have to do it all over again.”

Dr. Dumont says research now indicates this repeated resetting of the biological clock may be harmful. “The adaption can last a few days, and during that time the different clocks in the body are desynchronized,” she says. “What we want to do now is find a compromise position for the biological clock of night workers so they are never completely adapted to night work and never adapted to day work. They are in between, but their clock is not changing all the time, which is an unstable state that is very unhealthy.”

She says approximately 25 percent of the active work population now has a work schedule that affects their sleep. “We know that in the short term there are many problems associated with that, mostly sleep problems, but also vigilance problems, digestive problems, increase in cholesterol and weight gain.”

In addition, she says many published epidemiological studies in the last decade now indicate serious long-term problems associated with night work. “The main one is the risk of breast cancer in nurses with long-term exposure to night work. Now we also suspect very strongly – even if it’s not completely demonstrated yet – that there are also risks of metabolic disorders, diabetes, cardiovascular disorders and probably other kinds of cancer.”

UBC’s Dr. Whitehead says these findings, and the sheer numbers of people affected by the quality of light underscores the need for more quality research in this field. “Unfortunately it’s quite expensive,” he says. “To get good data, you need very large numbers of subjects.”

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