职称英语卫生类考试考前每日一练 Sleep Loss and Its Effects Mental fatigue can be as threatening as a heart attack. Recent evidence indicates that sleepiness is a leading cause of traffic and industrial accidents. Human error causes between 60% and 90%of all workplace accidents, depending on the type of job, observes biological psychologist David Dinges of the University of Pennsylvania.And inadequate sleep is a major factor in human error. Other research suggests that sleep loss contributes to everything from drug abuse to poor grades in school. A typical adult needs about eight hours of shuteye a night to function effectively. By that standard, millions of Americans are for a long time sleep deprived, trying to get by on six hours or even less. In many household, cheating on sleep has become an unconscious and harmful habit. In its mild form, its watching Ted Koppel and going to bed late and then getting up early to get to the gym, says Cornells Pollak. In extreme cases people stay up most of the night, seeing holy little sleep will keep them going. They try to compensate by sleeping late on weekends, but that makes up for only part of the shortfall. Over the months and years, some researchers believe, the imbalance builds up and. the effects accumulate. Most Americans no longer know what it feels like to be fully alert, contends Dr. William Dement, director of Stanford University s Sleep Center.
