Spring forward and fall back if you must, but be careful. A study released Thursday found a connection between Daylight Saving Time and an increase in fatal auto accidents. During the week or so after the spring time change, researchers determined that the risk of fatal car crashes rises about 6%—another 28 accidents, Courthouse News Service reports. The study considered whether the time change has other unwanted effects, such as causing more workplace accidents, heart attacks, or suicides. The evidence on those theories was inconclusive. But "the acute adverse effects of DST on fatal traffic accident risk are real and can be prevented," said Céline Vetter, senior author of the study and a circadian sleep scientist at the University of Colorado.
Sleep deprivation and circadian misalignment are part of the problem, says the study published in Current Biology. The dramatic change in lighting in the early morning each spring derails drivers' circadian rhythms for a period, making the darker, early morning commutes more dangerous. The effects of the change don't last long. But Vetter said, "We must not forget that DST transition affects billions of people every year, and thus small changes in risk can have a substantial public health impact." And she pointed out that the study didn't count serious but nonfatal accidents. The researchers said their goal is to see governments end Daylight Saving Time. (Read more Daylight Saving Time stories.)