A fast-growing body of research has linked artificial light exposure to disruptions in circadian rhythms, the light-triggered releases of hormones that regulate bodily function. Circadian disruption has in turn been linked to a host of health problems, from cancer to diabetes, obesity and depression. “Everything changed with electricity. Now we can have bright light in the middle of night. And that changes our circadian physiology almost immediately,” says Richard Stevens, a cancer epidemiologist at the University of Connecticut. “What we don’t know, and what so many people are interested in, are the effects of having that light chronically.”
Stevens, one of the field’s most prominent researchers, reviews the literature on light exposure and human health the latest Philosophical Transactions of the Royal Society B. The new article comes nearly two decades after Stevens first sounded the alarm about light exposure possibly causing harm; writing in 1996, he said the evidence was “sparse but provocative.” Since then, nighttime light has become even more ubiquitous: an estimated 95 percent of Americans regularly use screens shortly before going to sleep, and incandescent bulbs have been mostly replaced by LED and compact fluorescent lights that emit light in potentially more problematic wavelengths… READ THE FULL ARTICLE: www.wired.com
