Overhauling the lighting systems on U.S. roadways with light emitting diodes (LED) could have adverse consequences if improper LED technology is used, the American Medical Association (AMA) warned. In response, the group has adopted guidance for communities on selecting LED lighting options to minimize potential harmful human and environmental effects.
Converting conventional street lights to energy-efficient LED lighting has benefits such as increasing cost and energy savings and lowering reliance to fossil-based fuels. About a tenth of the U.S. street lighting has been converted to solid state LED technology with efforts to accelerate this conversion.
“Despite the energy efficiency benefits, some LED lights are harmful when used as street lighting,”say AMA Board Member Maya A. Babu, M.D., M.B.A. “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.”
High-intensity LED lighting designs emit a large amount of blue light that appears white to the naked eye and creates worse nighttime glare than conventional lighting, the AMA warned. Discomfort and disability from intense, blue-rich LED lighting can decrease visual acuity and safety, which could create a road hazard.
Additionally, the blue-rich LED streetlights operate at a wavelength that most adversely suppresses melatonin during the night, which can impact circadian sleep rhythms. A recent large survey found that brighter residential nighttime lighting can lead to reduced sleep times, dissatisfaction with sleep quality, excessive sleepiness, impaired daytime functioning and obesity.
Excessive outdoor lighting also disrupts many species of animals that need a dark environment, leading U.S. national parks to adopt optimal lighting designs and practices to minimize the effects of light pollution on the environment.
Recognizing the detrimental effects of poorly designed, high-intensity LED lighting, the AMA encourages communities to minimize and control blue-rich environmental lighting by using the lowest emission of blue light possible to reduce glare, the association said in a statement. “The AMA also recommends all LED lighting should be properly shielded to minimize glare and detrimental human health and environmental effects, and consideration should be given to utilize the ability of LED lighting to be dimmed for off-peak time periods.”
Source: American Medical Association