Federal Highway Administration and Department of Veterans Affairs Lighting Interventions
Phase I of GSA’s circadian lighting study found that not everyone had sufficient access to daylight to stimulate their circadian system. Other sources of lighting must also be considered for providing enough circadian stimulation, such as electric lighting. Phase II of the study explored connections between human health outcomes and supplemental electric lighting.
GSA collaborated with the Federal Highway Administration and the U.S. Department of Veterans Affairs to measure daytime alertness and the energy and vitality levels of participants to see if circadian-effective lighting delivered from LED lights could provide health benefits when they are needed the most: at work during the day.
GSA conducted a 3-day lighting intervention at the Federal Highway Administration Turner Fairbanks Highway Research Center in McLean, VA and at the VA Medical Center in White River Junction, VT by placing LED lights on the desktops of study participants.
Participants reported they felt less sleepy, had more energy, and were more alert during the workday with the LED lights turned on.
For more information, view the technical report:
Study Facts
- 3 day study; 1st day baseline (desktop LED lights not turned on); 2nd and 3rd day Intervention (LEDs turned on)
- Study took place in summer and winter
- 36 participants in summer; 26 in winter
- Participants wore light meter while at work for 3 days
- Completed 4 questionnaires throughout the 3 days that measured sleepy, alertness and vitality, and stress
Key Findings
- Desktop LED lighting increased the study participant’s circadian stimulus levels
- After 2 days of exposure to desktop LED lights, study participants reported they felt less sleepy
- Participants also reported they felt more alive, awake, alert and energized after just 2 days with the desktop LED lights turned on