ABSTRACT
Characteristics of shiftwork schedules can have distinct impacts on workers' sleep. This report presents comparisons of the effects of two different shiftwork schedules on duration and quality of the main sleep episodes in comparable worker populations at two different petrochemical plants. No significant differences were found for sleep duration in comparing the two plants. However, within each plant's shift cycles, morning and night shifts showed shorter sleep durations than all other workdays and days off. Quality of sleep was perceived as lowest for night shifts of both plant schedules, and of lesser quality for weekly than for fast-rotating shifts. These results support recommendations for reducing the number of consecutive nights of shiftwork. However, before recommending any optimal shift schedule, interactions of sleep duration and quality with shift schedules need much further evaluation.
Subject(s)
Personnel Staffing and Scheduling , Sleep/physiology , Workplace/organization & administration , Adolescent , Adult , Analysis of Variance , Chemical Industry , Cross-Sectional Studies , Humans , Male , Middle AgedABSTRACT
Cross-sectional studies of working and living conditions were conducted in two Brazilian petrochemical plants between 1988-1989. This paper presents analyses of reported activities undertaken during day- and shiftworkers' leisure time. One hundred and sixteen workers (67 continuous shiftworkers) daily logged standard protocols of all leisure activities, for three consecutive weeks. Workers logged 11,957 instances grouped in 27 different activities. The 14 most commonly mentioned leisure activities were analysed. Those most reported were meals with the family (breakfast, lunch, and dinner) and home TV viewing. Using chi 2 statistics, the results showed that the two factors studied--activities and work schedules (day and shift)--were not related. Analysing estimated coefficients of a second order log linear model, only a very few of the 14 activities most mentioned, did not differ in their frequencies between day and shiftworkers of the same plant. The same happened with the 12 activities most-mentioned of both plants: shiftworkers and dayworkers showed significant differences (p < 0.0001) on almost all frequencies of those activities mentioned. Hypotheses are made to explain some of the results. Home placement, and types of shiftwork schedules (weekly or swiftly rotating shifts) can be responsible for some of the activities performed during the workers' leisure time. Further investigation of those activities which are disturbed or cannot be performed due to work schedules is suggested.
