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The Very Real Ways That Light Pollution Affects Your Sleep and Mood
Artificial outdoor lighting doesn’t just drown out the stars
When the lights went out in Los Angeles after an earthquake in 1994, people called emergency centers to report a strange, giant, silvery cloud overhead. It was something they’d never seen before, something many humans alive today have not seen: the Milky Way, a swath of stars toward the center of our galaxy which, under totally dark skies in remote areas, graces the heavens like a river of silk. Without the bright lights of the city, many people experienced the natural phenomena for the first time.
Light pollution, or “loss of night,” as it is sometimes called, has only gotten worse since then, rendering all but a handful of stars invisible from big cities. But the effects go beyond frustrating backyard astronomers. Growing research suggests that bright outdoor lighting negatively affects sleep and moods in people young and old, and may even increase the risk of disease.
In places across America where artificial outdoor light is brightest at night, teenagers sleep on average 11 minutes less than teens in darker areas, according to a new study, published July 8 in the journal JAMA Psychiatry.
