VIGILANCE AND WORKING CONDITIONS

  In the modern world , the problem of maintaining vigilance arises with more and more acute . Indeed, the ongoing work tends to generalize in the industrial environment , and most services should now be accessible to users day and night. Moreover , the general trend is to reduce the number of operators and focus their work on monitoring tasks that require more attention. The problem of maintaining vigilance therefore arises whenever one asks a person to perform difficult tasks for a very long time or times of the day and night where its ability to stay awake are more reduced.

  Indeed , human performance is the level of vigilance and attention abilities that fluctuate with time of day . In some cases , the consequences of mistakes can be very serious . This problem of maintaining vigilance arises for anyone to work takes a more important dimension for people affected by night work or shift work . In addition, the recent introduction of 35 hours sometimes had unintended consequences on sleep quality of the employees concerned .

Night Work

  Whatever type of activity, night work is more difficult and requires a greater effort of attention compared to daytime work . The fall in the level of vigilance that normally occurs during the night leads to a strong desire to sleep or at least a reduction in the level of activity. These effects are associated with a reduction in attention span and perception of ambient signals that can lead to error . The feeling of fatigue and need for sleep are accentuated by the fact that the night worker is in a state of chronic sleep reduction , for sleep taken during the day is always shorter than the nighttime sleep . Industrial or aviation disasters occurred during the night , when vigilance is physiologically reduced, such as nuclear power plant at Three Mile Highland United States and Chernobyl in Russia.

  The sleep-wake system of man is designed to prepare the body and brain to sleep at night and be awake during the day . These natural rhythms make it difficult to sleep during daylight hours and oppose continued vigilance night hours , even in people who are well rested . It is even possible that the human body can never fully adjust to the activity at night and sleep during the day, even those who work permanently at night.

  Night work is particularly disturbing. Night workers trying to sleep during the day are often awakened by noise, light , telephone, other family members ... All disruptive elements that do not occur during the sleep of night workers diurnal protected by social habits that keep noise and disruption to a minimum during the night.