WASHINGTON (AP) —Reports of sleeping air traffic controllers highlight a long-known and often ignored hazard: Workers on night shifts can have trouble concentrating and even staying awake.
Czeisler said studies show that 30 percent to 50 percent of night-shift workers report falling asleep at least once a week while on the job.
So the notion that this has happened only a few times among the thousands of controllers “is preposterous,” Czeisler said in a telephone interview.
In a sign of growing awareness of the problem, the Federal Aviation Administration said it was changing air traffic controllers' work schedules most likely to cause fatigue. The announcement came after the agency disclosed another incident in which a controller fell asleep while on duty early Saturday morning at a busy Miami regional facility. According to a preliminary review, there was no impact on flight operations, the FAA said.
Czeisler said the potential danger isn't limited to air traffic controllers but can also apply to truck and bus drivers, airline pilots and those in the maritime industry.
Who else? Factory workers, police, firefighters, emergency workers, nurses and doctors, cooks, hotel employees, people in the media and others on night or changing shifts.
“We live in a very sleep-deprived society where many people are burning the candle at both ends,” Czeisler said. He said that a half-century ago, just two percent of people slept six hours or less per night; today it's 28 percent.
Dr. William Fishbein, a neuroscientist at the City University of New York, said that when people work odd shifts “it mucks up their biological rhythms.”
Hormones are synchronized with the wake-sleep cycle. When people change shifts, the brain never knows when it's supposed to be asleep, so this affects how people function.
People who change shifts every few days are going to have all kinds of problems related to memory and learning, Fishbein said. This kind of schedule especially affects what he called relational memories which involve the ability to understand how one thing is related to another.
In addition to drowsiness and inability to concentrate, people working night shifts are more subject to chronic intestinal and heart diseases and have been shown to have a higher incidence of some forms of cancer. The World Health Organization has classified shift work as a probable carcinogen.
One old solution back in the news is allowing night workers to nap.
“There should be sanctioned on-shift napping. That's the way to handle night shift work,” said Gregory Belenky, a sleep expert at Washington State University in Spokane.
A NASA study suggested that pilots on long-distance flights would perform much better if given a chance to take a scheduled nap, as long the rest was planned and the both pilots didn't sleep at the same time.
“But even though that's been known for decades, it's never been allowed because we prefer to pretend that these things are not happening,” instead of managing the problem, Czeisler said. “We have a bury-our-head-in-the-sand attitude.”
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Brigham and Women's Hospital's Division of Sleep Medicine: