STEVE INSKEEP, host:
This is MORNING EDITION from NPR News. I'm Steve Inskeep.
Today's report on your personal health examines shift work. One in five Americans routinely works nights. Scientists know that odd schedules create health problems, but solutions are not easy. In the first of two reports, NPR's Snigdha Prakash gives us one worker's solutions.
SNIGDHA PRAKASH reporting:
Night workers have a couple of biological strikes against them: They're working at a time when the body's internal clock is telling them to sleep, and they often build up what's called a sleep debt. That's because it's difficult to sleep during the day, so each night, as workers return to work, they're more tired than they were the night before. John McKinnon(ph) has been a shift worker all his working life. He's 58, and since 1986, he's worked at the Nuclear Regulatory Commission's Incident Response Center in Rockville, Maryland. The center was set up after the Three Mile Island accident to respond to problems of the nation's nuclear power plants, and it's staffed around the clock. McKinnon worked from midnight to noon this day, and soon, he'll be in bed. He's religious about his sleep schedule.
Mr. JOHN McKINNON (Shift Worker, Nuclear Regulatory Commission's Incident Response Center): It is now 12:31. I just arrived home, and I'll be going up the stairs here; driving home, felt a little tired like I normally do. Go upstairs, see my wife, read the newspaper, have something to eat, take a shower, go to bed.
PRAKASH: Eight hours after he goes to bed, around 10 in the evening, McKinnon wakes up, and he sounds pretty groggy.
Mr. McKINNON: At 10:18, my wife walks in the bedroom and tells me it's time to get up. She said, `Feel OK?' I said, `Yeah.' And then after that, I go in to the bathroom and wash my face, brush my teeth, and I'll be leaving the house here around 10:45 tonight. And right now, it's 10:27 in the evening.
PRAKASH: Experts say that to be successful at shift work, you have to take your sleep seriously, just as John McKinnon does. Charles Czeisler is professor of sleep medicine at the Harvard Medical School's Brigham and Women's Hospital.
Professor CHARLES CZEISLER (Harvard Medical School's Brigham and Women's Hospital): Those who end up succeeding at doing shift work for five, 10, 20 years actually have quite a structured routine that they start as soon as they are scheduled to work at night, and it involves setting aside an adequate amount of time for sleep every day and a cool, dark and quiet place in which to sleep.
PRAKASH: John McKinnon arrives at midnight at the NRC's Incident Response Center where he works. It's among a handful of work sites that use sophisticated technology to lessen the impact of shift work on employees; in this case, lighting run by a computer.
(Soundbite of door opening)
Mr. McKINNON: OK.
PRAKASH: This is very brightly lit.
Mr. McKINNON: This is actually lowest level right now of the lighting system.
PRAKASH: We're in a small working space. The walls are covered with maps. There are banks of phones and computers, and on the ceiling, there are 32 panels of lights. McKinnon says each panel has six fluorescent lightbulbs. They're special bulbs that emit wide spectrum light. And at 3:30 in the morning, they automatically start getting brighter. They do that for 30 minutes.
Mr. McKINNON: The time is 4:00 in the morning, Eastern time, and the lights are the brightest they're going to be right now. So it would be like a bright sunny day, so it makes you more alert, and you feel like you're outdoors. I'm not tired at all, and it's 4 in the morning.
PRAKASH: The lights will remain at the maximum level of brightness until 10 in the morning. Then, they'll gradually dim to ease McKinnon's transition at the end of his shift, 12 noon, so he can get to sleep when he gets home. A handful of government agencies use this technology. The astronauts at NASA use it; so do forecasters at the National Weather Service. The lights are based on research by Harvard's Charles Czeisler and others, and Czeisler says they help to reset the body's biological clock.
Prof. CZEISLER: If we get an adequate amount of light exposure during the night shift, we can, in essence, trick the brain; the night becomes our biological daytime, and the daytime becomes our biological night.
PRAKASH: But Czeisler says the lights are no panacea for the millions of workers on the night shift. They wouldn't work too well in trucker's cabs, for example, where bright lights would obscure the dark road. Czeisler says a lot is known about how to manage shift work, but the information isn't used. He says it's no surprise. As a society, Americans undervalue sleep. Snigdha Prakash, NPR News, Washington. Transcript provided by NPR, Copyright NPR.
