Bright bluish-white LEDs disrupt sleep, says US medical body

- Nov 15, 2018-

At a time when America is pushing LED lighting in full swing, some health issues pertaining to the use of LEDs have emerged that need to be taken care of, according to American Medical Association (AMA).

With the aim to save power, the US Department of Energy (DOE) has been supporting municipalities to switch to LED lighting. A number of towns and cities across the nation have already replaced their conventional street lamps with LEDs like in Las Vegas, Los Angeles, Seattle, New York City and New Orleans.
AMA’s recommendations

At its annual meeting, the US medical body pointed out that bright LED street lamps can cause harm to human health, particularly, high-intensity LEDs that mostly emit blue light as against the warmer-looking light of older street lamps produce glare, thus disrupting sleep cycles.

AMA recommended least-blue LEDs for those who wish to install LED lighting. Further, it suggests that people should opt for warmer 3000K LEDs rather than harsher 4000 K ones. It is also important to shield the light in a proper manner, AMA suggests.

Bright blue LEDs produce glare and reduce visual acuity, which may as well lead to road hazards, says AMA. Such high-intensity street lamps release a blue light wavelength that represses night time melatonin production, AMA pointed out.

In addition to this, surveys have found that brighter nighttime street lighting is linked with decreased sleep times, displeasure with sleep quality, extreme sleepiness, impaired daytime performance and even obesity, said AMA.

AMA highlighted the importance of proper designing of LED lighting products to prevent it from affecting human health. According to AMA, outdoor lighting at night should not have a color temperature more than 3000 Kelvin.

White LEDs at 4000K or 5000K produces high level of short-wavelength blue-light. This kind of LED street lighting has been installed in many cities like Seattle and New York. However, residents of Davis, California have complained against such lights.

According to AMA, white LED street lighting has two major problems. Firstly, they are discomforting and they glare. They are so high in blue content, that they lead to severe glare resulting into pupillary constriction in the eyes.

As per AMA guidelines, white LED lights are five times more effective in suppressing melatonin at night than high pressure sodium lamps. Melatonin decline is a big indicator of circadian disruption, resulting into disrupted sleep.