Study of daytime sleepiness among tunnel workers on rotating schedule

Introduction : Working on shifts, and especially, on a night shift, influences the endogenous sleep regulation system leading to diminished sleep time and increased somnolence. This may be dangerous in some cases, especially in large scale constructions, such as tunnels. Aims and objectives : The aim of our study was to examine whether sleep duration and daytime sleepiness differed between day and night shifts among tunnel workers. Methods : In this study 42 male workers (during the last semester) in a tunnel construction were recruited and examined at workplace. They underwent spirometric control and they were asked to complete a questionnaire referring to demographic factors, status of health and the Epworth Sleepiness Scale. Results : The workers present a mean age of 42 years old and a mean Body Mass Index (BMI) of 27.2 kg/m 2 . 69% of them were active smokers, while 31% have never tried smoking. Interestingly, 93% of the tunnel workers were consuming two coffees per day at least, while the remaining 7% were not drinking coffee at all. Almost one third of them reported alcohol consumption on a daily basis. Severe cardiologic, respiratory or endocrine disease was not reported among the participants and neither were depression and anxiety disorders. Our results showed that almost all the workers had gathered a score less than 10 in the Epworth Sleepiness Scale (a score of 10 or more is considered sleepy), except for two subjects in which statistical analysis did not reveal any statistically significant correlation between somnolence and the work schedule (p=0.88). Conclusions : The rotating shift in a dark and demanding environment, as in the tunnel construction, does not play a significant role in daytime sleepiness.