Fakhradin Ghasemi, Mostafa Mirzaei, Mohsen Mahdinia, Ebrahim Darvishi, Reza Shahidi,
Volume 6, Issue 2 (Journal of Ergonomics 2018)
Abstract
Introduction: Many organizational, social, and personal factors can affect safety performance of employees. Personal commitment to safety is another factor in this regard to which has been paid less attention in previous studies. The main objective of the present study is to investigate the role of this factor in shaping safety performance of employees.
Materials & Methods: This cross-sectional study was conducted among 302 workers from several small manufacturing industries in several provinces located in the center of Iran. Data were collected using a researcher-made questionnaire. In order to determine the role of personal commitment to safety, several hypotheses were defined. According to them, personal commitment to safety can mediate the effect of organizational factors on safety performance. Structural equation modeling (SEM) was employed for examining the hypotheses.
Results: The model demonstrated that personal commitment to safety has significant direct effect on safety performance. Management commitment to safety is the main factor affecting personal commitment to safety (P<0.01, path coefficient= 0.257). Supportive environment was another important factor in this regard (P<0.01, path coefficient= 0.175). In contrast, safety training had no significant effect on personal commitment to safety (P=0.328), demonstrating its poor designing.
Conclusion: Personal commitment to safety can be promoted by improving organization and social factors, such as management commitment to safety and supportive environment, which in turn would result in improvement of safety performance.
Reza Shahidi, Rostam Golmohammadi, Zahra Pirmoradi Rizevandi, Azar Soltani, Nassrin Shirmohammadi Khoram, Reza Kazemi,
Volume 8, Issue 1 (Iranian Journal of Ergonomics 2020)
Abstract
Background and Aim: Undesirable lighting at work environment causes visual and non-visual effects on employers. The aim of this study was to compare the quantity and quality of combined and artificial lighting in daytime and its relationship with the indexes of mental performance.
Methods: This study was carried out at 65 rooms and on 81 employees randomly selected from different clusters. Measurement of lighting parameters was done using a spectrometer. To assess the cognitive function, the Pshycomotor Vigiliance Task (PVT) test and for the sake of visual comfort, alertness and sleep quality, the Conlone, KSS (Karolinska Sleepiness Scale) and PSQI (Pittsburgh Sleep Quality Index) questionnaires were used respectively.
Results: Most artificial sources used in the rooms included fluorescent lights in different shapes and colors. The average indexes of combined lighting was more than artificial lightings (P<0.001). Visual comfort was correlated with high color temperature (P=0.006, r = 0.315). The employees with natural lighting had less visually impairment. The sleep quality of the subjects was related to the type of work environment lighting (Chi2=0.59, P=0.44). Alertness of subjects exposed to high color temperature or natural light was better at 8 and 11 hours. The results of cognitive performance test showed no significant difference between different lighting conditions.
Conclusion: Using natural light or artificial lights with adequate illuminance and high correlated color temperature can increase the alertness and visual comfort to some extent and improve the sleep quality of day staff employers.