Can sleeping in total darkness help reduce cancer risks? Does insufficient exposure to daylight affect immune systems? These important topics were discussed at a recent symposium, co-hosted by NRC and the Commission Internationale de l’Eclairage (CIE), an international standards body and professional association dedicated to the science and art of lighting.

Although this area of science is still relatively new, 164 multi-disciplinary experts from 23 countries gathered in Ottawa to discuss how light can influence our bodies and our well-being. Medical researchers, engineers, psychologists, architects, biologists, lighting designers and industry opinion leaders shared new research findings and considered how lighting installations should change to take into account this knowledge about health and light.
Wout van Bommel, President of the International Commission on Illumination (CIE) and a representative of Philips Lighting (Eindhoven, the Netherlands), delivers a presentation at the Symposium on Lighting and Health, held 7-8 September 2006.
Wout van Bommel, President of the International Commission on Illumination (CIE) and a representative of Philips Lighting (Eindhoven, the Netherlands), delivers a presentation at the Symposium on Lighting and Health, held 7-8 September 2006.

Dr. Jennifer Veitch from the NRC Institute for Research in Construction (NRC-IRC) says that people in western societies spend approximately 90% of their time indoors and they take lighting for granted.

Most of us think about lighting just in terms of energy efficiency, saving money on hydro bills, and aesthetics for home decor. We rarely weigh how much light exposure we get in a single day, or how little darkness we experience at night. Increasing light exposure in daytime appears to improve mood and well-being.

Researchers believe that using light and darkness to regulate sleep-wake cycles may benefit people around the world by:

* Helping travelers cope better with long international flights across numerous time zones;
* Assisting shift workers who need to adapt to irregular work hours;
* Minimizing sleep disruptions for Alzheimer’s patients; and
* Reducing cancer risks by ensuring production of melatonin, a hormone that regulates many bodily functions, and which inhibits cancer cell replication. Exposure to light at night suppresses melatonin production, and increases breast cancer risk, especially among night-shift workers.

NRC’s Indoor Environment program is developing a research program to identify the necessary daily light dose for good health. They plan to study specific times of day for exposure to light, particular types of lighting (spectrum), and the optimal lengths of time for exposure. The next step would be to determine how best to deliver that light dose in an energy-efficient way. Team members specialize in psychology, building physics, engineering and architecture.

Light & Health Tips:

* Sleep without any light at all for at least part of the night – install blinds, wear a sleep mask, direct exterior lights away from bedroom windows, and if a nightlight is essential, then use a red/amber one rather than a blue/green light.

* Build at least 15-20 minutes of bright light into your day, preferably early in the day. Daylight is the best source of very bright light, so if daylight doesn’t flow into your work space, then choose a seat close to and facing a window during your lunch break in a cafeteria/restaurant or take a walk outdoors.

Dr. Jennifer Veitch is proud that the event drew the best scientists from lighting-related fields while also providing a venue for design and lighting companies to get involved. The inaugural symposium was held in Vienna in 2004, and as one of Canada’s representatives to the CIE, Dr. Veitch convinced fellow symposium organizing committee members from around the world to bring the 2nd CIE Symposium on Lighting and Health to Ottawa, where NRC could co-host the event.

Dr. Veitch and her fellow organizers were amazed at the turnout. The symposium coincided with the August airport terrorist scare in England, and yet international participants from Europe, Asia and South America were not deterred from air travel. They joined their counterparts from North America to take part in panel sessions and learn more about important research projects.

Beyond the participants’ interest levels, Dr. Veitch was “flabbergasted by the overwhelming response” from media outlets, nationally and locally. She and others conducted interviews with many reporters and emphasized the importance of this research to human health and well-being, as well as the value of NRC’s role in bringing people from research communities together with industry representatives.

NRC-IRC’s strategic plan identified lighting and health as a key area for the institute’s research activities. Dr. Veitch and her colleagues intend to continue to strengthen existing relationships with their Canadian and international counterparts, and develop new effective working relationships with groups that have complementary skills, all in the interest of translating the research into building design and operation guidelines that can have a positive impact on human health.