Street and area lighting are among the most popular applications for LED sources. It’s estimated that more than 10% of streetlights have been converted to LED technology in the U.S.
Many LED streetlights exhibit characteristics that are very different than traditional high-pressure sodium sources. The popularity of LED streetlighting led the American Medical Association (AMA) to issue community guidance to communities installing it.
While acknowledging the benefits of LED streetlighting, AMA cautioned against possible health and safety impacts, notably resulting from poorly designed “high intensity,” blue-rich lighting.
“Despite the energy efficiency benefits, some LED lights are harmful when used as streetlighting,” says AMA Board Member Maya A. Babu, MD, MBA. “The new AMA guidance encourages proper attention to optimal design and engineering features when converting to LED lighting that minimize detrimental health and environmental effects.”
AMA advised communities to:
* Use LED lighting that minimizes blue spectral content
* Use sources that are 3000K CCT or lower
* Use luminaires that are properly shielded to prevent glare
* Consider dimming during off-peak operating times
Click here to download the AMA guidance (registration required).
Some AMA statements resulted in instant controversy.
The Illuminating Engineering Society issued a statement that said: “Of primary concern to the IES is the potential for this report and its ensuing press to misinform the public with incomplete or inaccurate claims and improper interpretations. We intend to respond to this through a proper analysis.”
IES added it hopes to work with AMA to ensure any lighting recommendations involve discussion with the IES.
Click here to read the IES response.
The Lighting Research Center issued a statement that included these key points:
* InGaN LED sources have greater potential than HPS to suppress melatonin (the hormone that regulates sleep-wake cycles)
* However, the amount and duration of exposure must be known before saying InGaN LED sources affect melatonin at night
* CCT alone is not enough to characterize the effect of a light source, in fact it’s misleading as it’s not really designed as a light and health metric
* Glare is mainly determined by amount and distribution of light entering eye, not light’s spectral content
Click here to download the LRC response.
The U.S. Department of Energy responded by stating there is nothing inherently dangerous about LED streetlighting. LED sources, in fact, offer advantages such as precise optical control, tailored spectral content and relative ease of dimming.
“Some media coverage can give the impression that LEDs are the enemy when in fact they’re a critical part of the solution, which the AMA acknowledges,” says Jim Brodrick, SSL Program Manager, DOE. “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 another technology, LEDs offer the capability to provide, for each application, the right amount of light, with the right spectrum, where you need, when you need it.”
Click here to read the DOE response.
NEMA also responded:
* AMA guidance aligns with industry recommendations for lighting controls, proper source shielding, and minimizing light levels and energy necessary for the task
* AMA recommendations for spectral content is problematic–it is one factor, and a single solution is not effective for all applications
“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,” NEMA stated. “As indicated by the U.S. Department of Energy (DOE) in its June 21, 2016, statement, CCT does not explicitly characterize the potential for nonvisual effects, which also depend on quantity and duration of exposure to light. The DOE further clarifies than 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. NEMA will issue additional technical guidance specific to the issues and tradeoffs related to the spectral content of lighting solutions.”
Click here to read the NEMA response.
It appears the AMA is well-intentioned here and raising some legitimate concerns, though their conclusions are questionable based on the research, and their solution may be oversimplified. They should consult the lighting industry on any lighting guidelines. IES has said it will contact AMA and seek to represent the lighting industry on lighting-related guidelines, which is very positive. As the lighting industry has been talking about light and health for some time, I’m surprised that link doesn’t already exist.
But even that would not have solved one of the biggest problems here, which is media ignorance about lighting and constant need to quickly and simply convey a story, which results in misleading instead of informing. In my opinion, IES needs to go even further to ensure that if the AMA sends a press release, that release not only promulgates guidelines IES endorses but also puts forward one or more lighting experts who can talk to the media and represent the lighting industry. These experts would get some type of media training.