Archives of

     
Table 4) Results of ANOVA regarding six domains of RSI

Category	P-value
Manual Material Handling	0.03
Handwork	0.45
Posture	0.00
Sensory	0.82
Environment	0.02
Personal Protective Equipment	0.76

 
handling (P<0.05). However, this test reported no significant relationship of the occurrence of occupational hazards in different jobs with the handwork, senses, and PPE domains (P>0.05, Table 4).
 
 

Discussion

 
This study aimed to conduct a job risk assessment using a macro-ergonomic viewpoint and RSI in an oil refinery repair workshop. Previously conducted studies have been shown that several factors, such as unsuitable working environment conditions and workstations, high workload, and the values of harmful factors in the working environment can have different effects on workers' health that leads to MSDs (23). On the other hand, regarding gathering data on the macro-ergonomic status of the organization, one can be informed about the general situation and harms of each job and use this information to allocate budget and time for further analysis to decrease the MSDs, thereby increasing the organization productivity (24).
Based on the results, it was found that among six domains related to the RSI, undesirable posture, manual material handling, and environment are the most important dimensions. Dehghan et al. and Tahmasebi et al. reported that undesirable posture was one of the most important risk factors for the development of MSDs, which was consistent with the findings of the present study (25, 26). It is impossible that the workers maintain the proper posture for the entire duration of the work. Moreover, due to the lack of a suitable workstation, all jobs in this field have some weaknesses. A limited number of studies have been performed so far to investigate the association of RSI parameters with MSDs in the industries. Therefore, the results cannot be compared in detail with those of other studies. Akbari et al. carried out a job risk assessment in a textile industry using the RSI. The results of their study showed that among the six domains, handwork and sensory have a significant relationship with occupation hazards. Furthermore, posture and manual material handling obtained the lowest and highest scores in RSI, respectively. The results of a study conducted by Akbari are consistent with the findings of the current study in terms of posture, not other domains. The discrepancies may be due to the differences between the two studies in terms of the work environment. Another reason may be the high effectiveness of environmental risk factors reported by the workers in the RSI calculation in the current study, including noise, humidity, work at high altitude and vibration, and heat in the working environment of the oil refinery repair workshop.
However, in a study carried out by Akbari, these factors have not been reported by the workers (21). Moreover, Barbarian assessed the job risks in the pharmaceutical industry using the RSI and reported that the MHL was the most important domain among the six RSI domains, which was in line with the findings of the present study (20). In a study performed by Kazemi et al. on 15 job groups in the textile industry, it was found that all job groups were in the green or safe zone; moreover, Dolatab and flyer jobs obtained the highest and lowest RSI values, respectively.
In addition to evaluating the environment, the RSI measures the level of individuals' fitness for performing tasks. The present study was also conducted in the textile industry (21). However, it is not possible to compare the score obtained from the RSI because of the different occupations. Based on the results, the rest was in the warning group indicating the dispersion of hazard levels in the workshop. In general, auxiliary devices, such as cranes, are used for transferring and moving the objects; however, in this workshop, the objects and loads were transferred manually since the cranes were defective. Moreover, the manual handling of loads is prevalent during a work shift in the workshop (20). In addition, Mousavi et al. and Moradi et al. concluded that employees working in the oil refinery are exposed to harmful factors, such as gases and chemical vapors, noise, shift work, and undesirable workstations, which can be cited as another reason for obtaining the highest score from the environment domain, compared to other domains (27, 28). The studied workshop is located in a closed environment with different sections and workers working with special expertise. The indoor environment and the lack of a proper ventilation system create a bad condition, which will affect the workers in different sections. For instance, the fume produced during the welding process or the noise generated during cutting can also influence other people, such as electricians working in other sections.
 Among the available jobs in the workshop, the welders obtained the lowest RSI value indicating that these workers are at high risk of exposure to harmful environmental factors. The reason for the low RSI score in welders is the undesirable posture and the bending and twisting of the low back due to the lack of a suitable workstation. The results of a study conducted by Choubineh et al. on the assessment of the risk of developing MSDs among welders showed that the risk of developing MSDs among welders was very high, and the poor posture at work was considered the most important factor in increasing the risk of developing MSDs among welders.
Similarly, Malikraj et al. found that welders tolerated an unfavorable physical condition for a long time so that they had to work in a sitting position with the trunk bent forward, which made the susceptibility to MSDs. This result is consistent with the findings of the present study (29, 30). In this study, macro-ergonomics was used to obtain a proper understanding of job requirements in the organization; additionally, 13 job groups and dangerous risk factors were identified in an oil refinery repair workshop. Hassani et al. stated that the negligence of the workplace and equipment standard created and exacerbated the MSDs. The body dimensions of the working people were studied from the viewpoint of the macro-ergonomics, and it was found that the workstation inadequacy caused an unfavorable posture in workers with a high level of risk (31).
Therefore, the results of this study can be used to eliminate or minimize the effects of exposure to these risk factors, which reduce the likelihood of musculoskeletal complications, accidents, as well as direct and indirect costs. This study was only performed on sensitive jobs with a small number of cases in each job due to taking a great deal of time, which can be mentioned as a limitation. However, since there are similarities between the work environment in oil refineries and the job characteristics, the results of this study can be used in other central workshops; nonetheless, necessary precautions should be considered. Therefore, it is suggested that future studies be conducted on a larger sample size in each job to remove the limitations.
 
 

Conclusion

 
Manual material handling, work environment, and undesired posture were identified as the most important risk factors associated with the development of MSDs in different job groups in an oil refinery central repair workshop. Therefore, some measures, such as the improvement of the workshop environment, establishment of an air conditioning system in the workshop, education on how to maintain proper posture while working, elimination or reduction of work activities, and enhancement of the workers’ workstation can be recommended to reduce the probability of the risk of developing MSDs among workers.
 
 

Footnotes

 
Acknowledgements
The authors would like to express special thanks to all those who contributed to performing this study.
 
Funding
This study was funded by Lorestan University of Medical Sciences, Lorestan, Iran (IR.LUMS.REC.1397.112).
 
Conflict of Interest
The authors declare no conflict of interest regarding the publication of the study.