Lighting groups including the IES and the Lighting Research Center at RPI were quick to respond in late June to the American Medical Association (AMA)’s recommendations for minimizing potential harmful effects of “high intensity LED street lighting.” Among its key recommendations in the report entitled “Human and Environmental Effects of Light Emitting Diode (LED) Community Lighting,” the AMA encourages both “minimizing and controlling blue-rich environmental lighting by using the lowest emission of blue light possible to reduce glare” as well as “the use of 3000K or lower lighting for outdoor installations such as roadways….”
The IES issued a preliminary response “to address the potential for the report and ensuing press to misinform the public with incomplete or inaccurate claims and improper interpretations.” The IES’s response includes an overview of the recommendations contained in the report, which was approved as part of the AMA’s Council on Science and Public Health (CSPAH) proceedings. The IES’s preliminary review of the AMA report found that:
- In 2012, the AMA prepared a Report A-12, “Light Pollution: Adverse Health Effects of Nighttime Illumination.” That 2012 report included 134 references and was consistent with IES Standards and findings. The 2012 report recommendations include, “Supports the need for further multidisciplinary research on the risks and benefits of occupational and environmental exposure to light-at-night.
- The new 2016 report contains 37 references, some of which are repeats from the 2012 report. Our first effort is to establish which of these 37 references, if any, provide any new information significant enough to warrant the change in AMA recommendations. We will also determine if any significant references were not included in the report, but should have been, to ensure accuracy.
- The IES was not represented in the deliberations leading to this document. We intend to contact the AMA and work with them to ensure that any lighting related recommendations include some discussion with the IES.
The IES statement concludes: “We are dedicated to performing a thorough and reasoned review of this AMA report, on behalf of the IES, our constituencies and the general public.”
A few days later, the LRC addressed the AMA claims, as professors Mark Rea and Mariana Figueiro of the LRC prepared a response available at https://www.lrc.rpi.edu/resources/newsroom/AMA.pdf.
The key points include:
- Predictions of health consequences from light exposure depend upon an accurate characterization of the physical stimulus as well as the biological response to that stimulus. Without fully defining both the stimulus and the response, nothing meaningful can be stated about the health effects of any light source.
- Notwithstanding certain sub-populations that deserve special attention, blue light hazard from In-Ga-N LEDs is probably not a concern to the majority of the population in most lighting applications due to human’s natural photophobic response.
- Both disability glare and discomfort glare are mostly determined by the amount and distribution of light entering the eye, not its spectral content.
- In-Ga-N LED sources dominated by short wavelengths have greater potential for suppressing the hormone melatonin at night than sodium-based sources commonly used outdoors. However, the amount and the duration of exposure need to be specified before it can be stated that In-Ga-N LED sources affect melatonin suppression at night.
- Until more is known about the effects of long-wavelength light exposure (amount, spectrum, duration) on circadian disruption, it is inappropriate to single out short-wavelength radiation from In-Ga-N LED sources as a causative factor in modern maladies.
- Correlated color temperature (CCT) is not appropriate for characterizing the potential impacts of a light source on human health because the CCT metric is independent of nearly all of the important factors associated with light exposure, namely, its amount, duration, and timing.