Many US cities have been making the move from sodium street lights to LEDs—the bulbs are not only up to 50% more energy efficient than their predecessors, but they last for as many as 20 years and distribute light more evenly. Unfortunately, numerous studies suggest that the levels of blue light in the high-intensity LED bulbs could have health ramifications, including sleep problems and even increased risk for cancer and heart disease. The evidence is apparently strong enough to prompt the American Medical Association to issue a warning in June that LED street lights can impair and even damage nighttime vision, reports Tech Times.
Problem is, almost 13% of roadway lighting now uses LEDs, with many places planning a switch, reports the Washington Post. Seattle has been downright dismissive of any health concerns, while New York has gone so far as to switch to lower-intensity LED bulbs the AMA considers safe when residents complain. Lake Worth, Fla., meanwhile, has plans to replace its sodium street lights with more than 4,000 LED lights that have less of the potentially harmful blue light and more of an amber hue, while Gloucester, Mass., has consulted its own residents and decided to play it safe and go with less blue in their LEDs, which they'll finish installing next month. But not everybody's convinced the danger is real: "Nobody says don’t watch television or use your computer after 9pm because of blue lights," grouses one Phoenix official to the Post. (This major company is making the switch to LEDs.)