Ahjo (16.01.2004 - Mika Peltonen/UP) Continuous sleep deficit causes a serious safety risk at the workplace, says sleep researcher and neurologist Markku Partinen. "A tired employee more readily takes risks than a well rested employee, as tiredness weakens attentiveness and observation." For example, a tired worker will not necessarily notice that an industrial control room meter is over the red line and the process is running foul.

"In the long run a tired employee is no good to the employer, either. Even where loss of life and serious catastrophes are avoided, the financial losses may be really serious." According to Partinen, a 16-hour period without sleep already poses a significant risk, and is comparable to a blood alcohol content of 0.5 per mille.

Staying awake for 24 hours is comparable to a blood alcohol content of 1.0 per mille, and 36 hours without sleep corresponds to drunkenness of 1.5 per mille.

Sleeping too little night after night is also a problem. If human beings sleep for a clearly shorter period than they need for six consecutive nights, then the mind no longer functions normally, matters are overlooked and judgement is impaired.

Stress is the most common cause of insomnia. Work alone does not necessarily cause stress, Partinen says, but if, for example, problems at home coincide with difficulties at work, then the pressure accumulates and the consequences become easily recognisable.

The people who usually suffer most from sleep deficit are those who are the most profitable employees, Partinen reports. "This reflects the paradox that often it is busy, responsible individuals who are committed to their work who suffer from insomnia. They begin to take their work home and neglect their social life and relaxation.

According to Partinen, the cheapest preventive occupational safety measure would be good quality sleep. However, one problem is that physicians and other health care personnel know too little about the significance of sleep deficit.

"There has been no systematic instruction in the medical science of sleep. This has resulted in haphazard provision of care in cases of sleep deficit."