by Brianna Crandall — July 1, 2016 — The American Medical Association (AMA) recently adopted guidance for communities on selecting among light-emitting diode (LED) outdoor lighting options to minimize potential harmful human and environmental effects when converting street lights to LED lights to save energy and costs. The National Electrical Manufacturers Association (NEMA) released comments last week in response to the guidance, as did the U.S. Department of Energy (DOE).
American Medical Association (AMA)
In its community guidance, AMA supports light pollution control efforts and glare reduction for both public safety and energy savings. It endorses converting U.S. street lighting to solid-state LED technology, but warns that some LED lights are harmful when used as street lighting, and encourages communities to give proper attention to optimal design and engineering features that minimize detrimental health and environmental effects when converting.
AMA’s concerns lie with high-intensity LED lighting designs that it says emit a large amount of blue light that appears white to the naked eye and can create worse nighttime glare than conventional lighting. AMA says the intense, blue-rich LED lighting can decrease visual acuity and safety, resulting in discomfort and vision concerns and creating a road hazard. The organization says the blue-rich LED streetlights operate at a wavelength that most adversely suppresses melatonin, impacting circadian sleep rhythm and leading to reduced sleep times and impaired daytime functioning and obesity.
AMA also notes the detrimental effects of high-intensity outdoor lighting on many animal species that need a dark environment. The organization concludes by encouraging communities to minimize and control blue-rich environmental lighting by using the lowest emission of blue light possible to reduce glare. In addition to a maximum intensity threshold, AMA recommends all LED lighting should be properly shielded, and advises that LED lighting be dimmed for off-peak time periods.
National Electrical Manufacturers Association (NEMA)
NEMA says it is a long-time proponent of good quality lighting design and application, with technical standards and guidance for manufacturers and their end-use customers. The organization says the AMA’s community guidance on LED outdoor lighting is aligned with lighting manufacturers’ long-standing recommendations on how to design safe and efficient light for night, including:
- Using lighting control options such as motion or dusk-to-dawn sensors
- Shielding the light source to curtail excessive uplight, sidelight, and glare
- Designing for the minimum light levels and energy necessary for the task
NEMA and its lighting manufacturer members support the proper application of light at the right placement, right time and in the right amount. NEMA says its members actively assist installers and customers with the best application and maintenance of their products. Consequently, there are few technical reasons or limitations to stand in the way of preventing misdirected light and glare. NEMA member products are readily available for a wide array of solutions.
NEMA says AMA’s recommendations regarding the spectral content of outdoor lighting installations raise serious concerns for electrical manufacturers. NEMA agrees that spectral content should be one factor in effective lighting for outdoor installations, but says a single solution is simply not appropriate for all situations. NEMA also questions the wisdom of assigning significant weight to this recommendation since outdoor lighting design requires a complex analysis of many criteria. Outdoor lighting systems will vary depending on the application and local conditions. Tradeoffs in the considerations of visibility, environmental impacts, energy efficiency, cost, personal safety and security need to be optimized, which cannot be achieved with a single solution, asserts NEMA.
According to NEMA, the AMA recommendation encouraging the use of 3000K correlated color temperature (CCT) or lower may compromise the ability of the lighting system to meet all critical design criteria for each unique application. As indicated by the U.S. Department of Energy (DOE) in its June 21, 2016, fact sheet (see below), CCT does not explicitly characterize the potential for nonvisual effects, which also depend on quantity and duration of exposure to light.
DOE further clarifies that an LED light source with the same CCT as a non-LED source has about the same amount of blue spectral content. The AMA recommendation for 3000K or lower is not an appropriate solution for all applications, nor is it is supported by the current body of research, says NEMA. NEMA will issue additional technical guidance specific to the issues and tradeoffs related to the spectral content of lighting solutions.
NEMA says it welcomes the opportunity to work with AMA and other organizations on projects to further research the complexities of night lighting. The organization says it is committed to science-based improvements to night lighting so that people the world over can safely and efficiently enjoy the extension of their living space as well as the beauty of the nighttime natural world.
U.S. Department of Energy (DOE)
As mentioned above, DOE also released a fact sheet in response to AMA’s concerns, legitimizing the concerns but pointing out that many of these long-term issues relate to all outdoor lighting rather than to LED lighting specifically. DOE says there is nothing inherently different about the blue light emitted by LEDs, nor is there anything inherently dangerous about LED lighting, but “it should be used with the same prudence with which we use any other technology:” direct the light only where it is needed; make sure the emitted spectrum supports visibility, safety, and the health of humans and other living creatures; and limit glare for pedestrians, bicyclists, and drivers.
DOE points to the advantages of LEDs, particularly their dimmability when lower illumination is required; the high degree of control they offer over the pattern and evenness of light on the ground (rather than wasted in the sky); their lower use of energy for the same illumination requirements; the ability of their spectral content to be tailored to order (blue light emitted can be minimized); and their availability in a range of possible CCTs.
Asserting that LEDs are a “critical part of the solution” to concerns about blue light, light at night, and dark-sky issues, DOE concludes that “the key takeaway from the AMA’s guidance is the importance of properly matching lighting products with the given application, no matter what technology is used. More than any other technology, LEDs offer the capability to provide, for each application, the right amount of light, with the right spectrum, where you need it, when you need it.”
“Get the Facts: LED Street Lighting” is available on the DOE Web site.
