Carefully lighting the way

As cities replace streetlights with more energy-efficient LEDs, decisions about the type of LED lights selected should be taken into consideration, doctors say.

The American Medical Association adopted a community guidance report at its annual meeting this summer to help communities select lights that will have the least amount of human and environmental effects.

According to a news release on the AMA website, high-intensity LEDs put off a large amount of blue light that creates glare and is a road hazard. In addition to decreasing visual sharpness, the blue-rich LEDs suppress melatonin during the night and impact circadian rhythms. The impact is felt in animal species, as well.

“Brighter residential nighttime lighting is associated with reduced sleep time, dissatisfaction with sleep quality, nighttime awakenings, excessive sleepiness, impaired daytime functioning and obesity,” the report says. “White LED streetlighting patterns also could contribute to the risk of chronic disease in the populations of cities in which they have been installed.”

The AMA recommends “3,000K or lower lighting for outdoor installations such as roadways” and that municipalities shield their lights and consider dimming them in off-peak periods.