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Project Highlights

Investigating the Health Impacts of Outdoor Lighting

VTTI is currently working on a project with the Department of Energy to quantify the effects of outdoor lighting that utilizes Solid State lighting (LEDs) on melatonin in humans. Melatonin is a hormone that is involved in the regulation of circadian rhythms. The dimming and instant-on capabilities of LED sources coupled with their improved efficiency have allowed lighting designers to address the drawbacks of previous technologies, especially with regard to energy usage in outdoor environments. However, it is also important to further investigate the health and environmental impacts of LEDs with regards to the emitted light spectrum as the incorrect exposure can lead to sleep disorders and other health problems.

A recent American Medical Association (AMA) report shared reservations about the blue content in the LED spectrum and its effect on the physical, mental, and behavioral patterns in humans. However, even with the AMA concerns, no empirical studies have quantified the potential health effects of any component of the spectrum in real-world outdoor lighting settings.

The project will measure the impacts of lighting on drivers, pedestrians, and people experiencing unwanted light as they sleep from streetlights. Data collection occurs through incorporating light sources with different correlated color temperatures in a naturalistic setting for a 2-to-3-hour timespan. The results of this study will help guide decisions that manufacturers and designers to select light sources for outdoor areas and also inform the public of the possible health implications of outdoor lighting.

The project is ongoing. For further questions, please contact Dr. Ron Gibbons at rgibbons@vtti.vt.edu.