Comparison of Shift Work-related Health Problems in 12-hour Shift Schedules of Petrochemical Industries

Shiftwork that affects diverse aspects of human life is arranged in various schedules, each has its own advantages and disadvantages. This study was carried out with the objectives of determination of common 12-hour shift schedules in petrochemical plants, comparison of shift work health-related problems among employees working in different shift schedules and recommendation of appropriate shift schedule for decrement of related health problems.

This cross-sectional study was conducted at 8 petrochemical plants in Asalooyeh region related to National Petrochemical Industries in which 12-hour shift schedules were applied. Study population consisted of 549 shift workers with age mean of 29.83±5.75 years. Data on personal details, shift schedule and adverse health effects of shiftwork (i.e. gastrointestinal, cardiovascular, musculoskeletal, psychological, sleep etc. disorders) were collected by anonymous questionnaire.

Among 549 studied shift employees, 39.6% worked in 4N-7D-3N-7Res (4night-7day-3night-7rest), 29.1% in 7N-7D-7Res and 31.3% in 7D-7N-7Res schedules. Statistical comparison showed that the prevalence of h ealth problems such as gastrointestinal, cardiovascular and musculoskeletal disorders among 7D-7N-7Res schedule shiftworkers were significantly higher than that of other schedules (p<0.05). Furthermore, the results revealed that the prevalence rates of health problems among 4N-7D-3N-7Res schedule shift workers were higher than 7N-7D-7Res schedule workers, but the differences were not significant (p>0.05).

Prevalence of gastrointestinal, cardiovascular and musculoskeletal disorders in all schedules were high, but odds ratios of all problems among 7D-7N-7Res schedule shiftworkers were significantly more than those of the shiftworkers of the other schedules. This schedule should, therefore, be changed to decrease related-health problems. Fixed 14D/14N schedule may be an appropriate substitution.