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You may have noticed them in your city: High-intensity LED streetlights, which make it easier to see at night but which also tend to have a somewhat harsh quality about them. These lights emit an unseen blue light in addition to the bright white light we see, and that blue light could be seriously affecting people’s health.

The Washington Post reports that the American Medical Association has issued a warning about these lights, adding some credibility to preexisting concerns over this type of lighting. Allegedly, the blue light can disturb sleep rhythms, and can potentially increase the risk of both cancer and cardiovascular disease. Yikes.

Melatonin is secreted at night, and helps our bodies balance between sleeping and waking by regulating our circadian rhythms and keeping the production of other hormones, like adrenaline, in check.

In its warning, the AMA did note that studies had linked bright LED lights to poor sleep quality, a decrease in the amount of time a person sleeps, and more difficulty with daytime functioning.

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While the AMA’s report might make it seem like we should stop using LEDs completely, that’s actually not the case: The organization still praised the lights for their effectiveness and energy efficiency.

However, they recommend LEDs no stronger than 3000K — lighting is measured by kelvin, abbreviated to “K,” which refers to its color temperature. The first LED streetlights had temperatures of 4000K, and produce a lot of that potentially dangerous, unseen blue light. The AMA essentially hopes that cities continue to use LEDs, but minimize their use of harsher, blue-rich lighting above 3000K.

There are LEDs available with lower kelvin ratings – they have about the same level of energy efficiency, don’t admit as much blue light, and have a somewhat amber glow. Overall, they sound better for everyone’s comfort as well as their well-being, and hopefully cities consider them when replacing their older, more traditional streetlights with LED ones.