Shift work-related health problems in "12-hour shift" schedule in petrochemical industries.

Background and aims: Shift work is a major feature of working life that affects diverse aspects of human life. The main purposes of this study were to investigate work-related health problems and their risk factors among workers of 12-hour shift schedule. Methods: This cross-sectional study was carried out at 8 petrochemical industries in Asalooyeh area. Study population consisted of 1203 workers including 549 worker (46%) and 654 day worker (54%). Data on personal details, schedule and adverse effects of work were collected by anonymous questionnaire. Statistical analyses were performed using SPSS, version 11.5. The level of significance was set at 5%. Results: Although, the results showed that health problems among workers was more prevalent than day workers, but the differences were just significant in gastrointestinal and musculoskeletal disorders (p<0.05). Multiple linear regressions indicated that in addition to working, other variants such as long work hours, type of employment, second job, number of children and job title were associated with health problems. Conclusions: Prevalence rates of gastrointestinal and musculoskeletal problems among workers were significantly higher than that of day workers. Although, working in system was the main significant factor associated with the reported problems, but other demographic and work variables were also found to have association.