Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, January 25, 1994 TAG: 9401250052
SECTION: EXTRA PAGE: 1 EDITION: METRO
SOURCE: Jane Brody
DATELINE: LENGTH: Long
Chances are, every one of those sleep-deprived people is less than fully alert and is performing below par. Many are so sleepy that they are likely to nod off at the drop of a hat - while reading, listening to a lecture, driving on a monotonous road, flying on autopilot.
Even if they do not fall asleep, their ability to attend to crucial details, like which runway to land on, and their judgment are likely to be seriously impaired.
It is more than a coincidence that most of the major catastrophes of our time, including Three Mile Island, Chernobyl, Bhopal and the Exxon Valdez oil spill, occurred at night under the auspices of workers who had been awake for many hours, including the wee hours of the morning when the human body is programmed to sleep.
Nor is it unheard of for all three officers in the cockpit to doze off at the same time, as aviation experts have repeatedly reported.
Although no major airline accident has been linked directly to a sleepy cockpit crew, undue fatigue has resulted in pilots' failing to read gauges correctly and landing not only on the wrong runway but even at the wrong airport.
Among drivers of automobiles, long-haul trucks and even buses, sleepiness is believed to be responsible for a large share of fatal and nonfatal accidents. Those drivers who live to tell the tale often report that they did not know they were about to fall asleep; it just happened.
Dr. William Dement, a sleep disorders specialist at Stanford University, says many sleep-deprived people are as likely to fall asleep suddenly under inappropriate and even dangerous circumstances as are people with serious sleep disorders, like sleep apnea and narcolepsy.
Sleepiness has become an endemic condition in our modern 24-hour society, where light bulbs and television sets prompt people to postpone bedtimes and assign alarm clocks to arouse them each morning. Meanwhile, one-quarter of the work force must labor all night.
Even for those who work ordinary days, the demands of modern life - job or career, family time, recreational activities, shopping, cooking, cleaning, repairing and staying in shape - leave little time for sleep.
It is not uncommon for top executives to attribute their success to the fact that they sleep only three or four hours a night, but sleep experts say that this is nonsense and that bosses would be far more effective if they slept more.
Evolution programmed humans to go to sleep soon after nightfall and to arise as the dawn breaks, which at the equator (where human beings evolved) means people would sleep about nine hours a night.
And indeed, studies in sleep laboratories, where people live without knowing when it is day and night and have no alarm clocks to tell them when to arise, have shown that most adults need eight to eight and a half hours of sleep a night.
But in real life they get less than seven. With each foreshortened night, they add to their growing sleep debt until they reach a point where they can no longer voluntarily stay awake. Should involuntary sleep occur while they are driving, the consequences can be life-threatening, and not just for the sleepy driver.
The federal Department of Transportation estimates that each year 200,000 reported automobile accidents are sleep-related. The National Transportation Safety Board has found that fatigue accounts for nearly one-third of the trucking accidents in which the driver dies, and four innocent victims die along with every commercial trucker.
According to Dr. James Maas, a professor of psychology who is a sleep researcher at Cornell University, the most sleep-deprived of all are high school and college students.
As Maas knows from firsthand observation, college students are notorious for falling asleep in class, in the library or in their rooms surrounded by piles of books.
From the ages of 17 to 25, sleep needs are greater than at any other time of life after early childhood, but the pressures to postpone or even skip sleep are also greatly increased.
Sleep studies have shown that these young people need about 10 hours of sleep a night. Yet the average student sleeps only six hours, accumulating a sleep debt that grows by four hours a night.
Even if they do not doze off in class, their alertness, ability to remember, judgment, reaction time and mood can be severely compromised by their inherent sleepiness.
Many parents bemoan their teenagers' "laziness" because they sleep until noon on weekends, but most of these young people are only trying to cancel some of their week-long sleep debt.
Experts believe a large share of accidents caused by young drivers are related to sleep deprivation, either directly, for those who fall asleep at the wheel, or indirectly, for those who fail to respond quickly and appropriately to avert a possible accident.
In addition, against a background of sleepiness, a small amount of alcohol can have a large intoxicating effect.
Dement said that in a person with a typical student's sleep debt, one beer has an impairing effect equivalent to that of a six-pack consumed by a well-rested person. Yet few students would refrain from driving after drinking one beer.
Elderly people also are often sleepy when they want to be most alert. Contrary to popular impression, sleep needs do not decline with age. Rather, the ability to get a consolidated night's sleep diminishes.
Illness, pain or simply the need to urinate one or more times a night disrupts the sleep of many older people, some of whom can become as sleep-deprived as those with actual sleep disorders unless they are able to nap during the day when they feel sleepy.
Another group of people who are chronically sleep-deprived are those who work nights, and especially those who do shift work that rotates from day to night and back again.
Night and night-shift workers typically come home exhausted, yet have difficulty falling asleep and staying asleep during the day. Their biological clocks, which are set by daily cycles of light days and dark nights, never adjust to night work. Their disrupted weekday sleep is often compounded by their desire to join family and friends for daytime activities on weekends.
According to Mark Rosekind, a sleep specialist at the space agency's Ames Research Center at Mountain View, Calif., "an estimated 75 percent of night workers experience sleepiness on every night shift, and for 20 percent sleepiness is so severe that they actually fall asleep."
Shift workers also have high rates of serious health problems, including gastrointestinal and cardiovascular disorders, which probably result from stresses inherent in their disrupted sleep lives.
Night workers and rotating shift workers also have high rates of psychosocial problems, including family difficulties and emotional disorders.
Next week: how to recognize and correct sleep deprivation.
New York Times
by CNB