title: Examining fatigue and insomnia symptoms among workers of a gas transmission industry in 2013.
abstract: BACKGROUND
  Fatigue, which interferes with one's physical and mental operation, resulting in strength reduction and weakness, is considered one of the most important issues in the workplace. In addition, it can cause diseases, occupational accidents, and a reduction in an individual's efficiency. The aforementioned effects can be aggravated by fatigue in shift workers who experience sleep disturbance. The aim of this study was to investigate fatigue and the Insomnia Severity Index (ISI) among workers of a gas transmission industry in 2013.
  
  
  METHODS
  This descriptive analytical study was conducted among 300 workers of the aforementioned industry and required data was collected via the face-to-face survey method and questionnaires. Data analysis was done with the following techniques: Mann-Whitney, variance analysis test, independent t-test, Kruskal-Wallis, Spearman's correlation test, and chi square test.
  
  
  RESULTS
  The highest fatigue scores among fixed-dayshift and rotating-shift workers were 6 and 7, respectively, and the fatigue level for both groups was 4. The average of all symptoms associated with fatigue and the total score on the Insomnia Severity Index in rotating-shift workers were higher than for dayshift workers and there was a significant difference between them (P=0.001). Lack of concentration, exhaustion, and fatigue during work were the most common symptoms of fatigue among the aforementioned shift workers in this evaluation.
  
  
  CONCLUSIONS
  The findings indicated that the level of fatigue and severity of insomnia among workers of this gas transmission industry is very high. Since this can lead to occupational accidents and efficiency reduction, it is necessary to provide workers with opportunities such as short breaks during working hours, rest and exercise during work, paying adequate attention to the workers' human needs, and improving work systems.
authors.affiliation: M.Sc. Student of Health Safety and Environment (HSE), Aras International Campus, University of Tehran, Tehran, Iran.
authors.forename: Razmik
authors.initials: R
authors.lastname: Moradifar
authors.affiliation: Assistance Professor, Faculty of Environment, University of Tehran, Tehran, Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Hoveidi
authors.affiliation: Assistance Professor, Faculty of Environment, University of Tehran, Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Givehchi
authors.affiliation: M.Sc. Student of Health, Safety and Environment (HSE), Shakhes Pajouh University of Isfahan, Isfahan, Iran.
authors.forename: Faranak
authors.initials: F
authors.lastname: Talebi
keywords: fatigue; fatigue symptoms; insomnia severity index; shift work