Workload and psychophysiological stress reactions in air traffic controllers

Interactions between workload and psychophysiological stress symptoms were investigated in a population of 205 predominantly male air traffic controllers (ATCs) from the area control centre (ACC) and the airport control tower (TWR) in Zurich and Geneva. Each subject completed two questioning sessions and two working sessions, the first time during a period of low traffic and the second time during a period of high traffic. For the questioning sessions standardized questionnaires were used. For all investigated working sessions, different aspects of the subjective and objective workload were recorded. Before and after each session, a saliva sample for assessing the concentration of secreted cortisol was taken. The questionnaire parameters represented psychological stress symptoms, such as complaints of physical discomfort, depression, negative self-communication, work-increased anxiety, coping behaviour and subjective rating, and interpretation of various aspects of the working situation. The mean values measured were within the normal range, and only a few significant differences between the two questioning sessions were found. However, about 10 to 15% of the ATCs showed elevated values in psychological stress symptoms to an extent indicating that they might have serious stress problems at work and/or in their private life. The investigated working sessions showed that the ATCs' subjective ratings correspond clearly to their cortisol response and the objective workload. Thus, ATCs' complaints regarding excess work stress should be taken seriously.