Rasoul Hemmatjo, Abolfazl Ghahramani, Mansour Mahmood Aghbash,
Volume 12, Issue 4 (Iranian Journal of Ergonomics 2025)
Abstract
Objectives: Numerous factors such as job types and conditions, work organizations, and individual characteristics affect work ability of the workers. Furthermore, occupational stress is not solely influenced by individual characteristics; a stressful work environment is also a significant source of stress. Noise has been recognized as one of the major occupational hazards that adversely affects work condition in many industries. In the present study, the association of noise exposure with occupational stress and work ability of the workers in a food processing plant was investigated.
Methods: This descriptive-analytic study was performed on 142 workers of a food processing plant in various work groups. The OSIPOW questionnaire results were utilized to measure occupational stress and the work ability of the workers was determined by Work Ability Index (WAI) questionnaire. Noise exposure of the workers was calculated as a measure of 8-hour time weighted average. The association between noise exposure and work ability was analyzed using Pearson and Spearman correlation tests. Multiple regression test was utilized to analyze the simultaneous effect of variables. Moreover, one-way analysis of variance (one-way ANOVA) was used to analyze the mean difference of independent variables.
Results: The findings demonstrated a significant positive association between noise exposure and stress level across various work groups (P<0.001). Furthermore, a significant negative relationship can be found between noise exposure and work ability of the workers (P<0.001). A simultaneous analysis of variables influencing occupational stress and WAI showed that noise had the most effect. Although occupational stress levels were not significantly different across working groups, mean difference of WAI was significant.
Conclusion: Based on the obtained findings, higher levels of noise exposure may contribute to increased occupational stress and decreased work ability among workers.
Zahra Sadat Sharifi, Rasoul Hemmatjo, Abolfazl Ghahramani,
Volume 13, Issue 3 (Iranian Journal of Ergonomics-In Press 2025)
Abstract
Background and Objectives: Nowadays, electronic devices such as computers, mobile phones, and tablets have played an important role in people's work and lives, and the main complaint of users of video terminals is eye symptoms caused by them. This study aimed to evaluate the intensity of lighting and brightness and its possible relationship with visual fatigue in users of video terminals at Tabriz University of Medical Sciences.
Methods: This cross-sectional study was conducted on 171 users of video terminals at Tabriz University of Medical Sciences. In this study, the local illuminance intensity at the work surface and the luminance intensity from the screen at the user's eye level were measured. A 15-question visual fatigue questionnaire was used to assess visual fatigue. The results were analyzed using paired t-tests and chi-square tests using SPSS software.
Results: In this study, the average local illumination intensity on the desk was 306.6 lux and the average luminance intensity was 73.9 candelas per square meter. Local illumination intensity was lower than the recommended level in 41.6 percent of cases. There was no statistically significant relationship between illumination intensity and users' vision during the study, and there was also no statistically significant relationship between users' luminance and vision. The results of this study showed that vision at the end of the work has a significant relationship with the individual's vision at the beginning of the work. The results of this study also showed that there is a significant relationship between visual fatigue and the type of work.
Conclusion: According to the findings of the study, it is recommended that, if possible, the time to start working with visual terminals should be when there is no feeling of visual fatigue. Also, since one of the factors affecting visual fatigue is the type of work, it is recommended that users manage their work in such a way that they are mostly inactive (reading the page).
