Experience and limited lighting may affect sleepiness of tunnel workers

BACKGROUND: Working on shifts, especially on a night shift, influences the endogenous sleep regulation system leading to diminished sleep time and increased somnolence. We attempted to evaluate the impact of shifts on sleepiness and correlate the sleepiness score to the experience in a shift schedule. MATERIALS AND METHODS: This cross-sectional study consists of 42 male and 2 female workers involved in a tunnel construction. They underwent spirometry, pulse oximetry and were asked to complete the Epworth Sleepiness Scale questionnaire. RESULTS: Statistical analysis revealed that workers of lower Epworth had a mean age of 43.6 years, compared to the mean age of 36.4 years of workers with higher Epworth. Furthermore, workers of lower Epworth were characterized by a mean number of shift years equal to 14.8, while those of higher Epworth possessed a mean number of shift years equal to 8. The shift schedule did not reveal any statistically significant correlation. CONCLUSIONS: Workers employed for a longer time had diminished sleepiness. However, there is no relationship between night shifts and sleepiness, possibly because of exposure to artificial lighting in the construction site.