Journal of Occupational Hygiene Engineering
Year:2023 | Volume:10 | Issue:1|Papers Count:8

Background and Objective: Noise pollution inside buildings is caused by frequent sound reflection from their inner surfaces. The purpose of this study is to experimentally study the sound emission pattern based on acoustic characteristics in typical industrial manufactories. Materials and Methods: This study was conducted in rectangular cubic manufactories with a volume of less than 2000 m2, between 2000 to 3000, and 3000 to 4000. The space reverberation time was measured according to the ISO 3382-2-2008 standard, and the sound emission pattern in manufactories was performed according to the ISO 11690 standard. The space sound level was measured based on the distance from the source with pink noise. In order to simulate sound parameters, the radiation tracking method was used in Odeon. Data analysis was conducted using the SPSS software. Results: The average reverberation time in manufactories under 2000, between 2000-3000, and between 3000-4000 m2 was 1. 75, 2. 25, and 2. 77 sec, respectively. The measured reverberation time had a significant correlation with the predicted reverberation time (r=0. 95, P=0. 05). The average sound reduction based on the distance from the source was 4, 3, and 3 dB in manufactories under 2000, between 2000-3000, and between 3000-4000 m2, respectively. There was also a negative significant correlation between the sound reduction level and the reverberation time (r=-0. 97, P=0. 05). The correlation between the measured and predicted sound levels was determined (r=0. 95). Conclusion: Reverberation time calculated by Sabin and Eyr ing’, s formula showed higher values than those of the measurement method. There was also a significant relationship between the average sound reduction pattern and the average time of vocalization. Therefore, measuring sound reduction based on the distance from the artificial source can be used to show the sound emission pattern, even on its own, due to the simplicity of the measurement method. It is recommended to be used with the reverberation time to evaluate the sound emission pattern in manufactories.

Background and Objective: Assessment of safety performance in a work environment is one of the most important steps in establishing optimal safety conditions in an organization. The present study aimed to assess safety performance in a food industry. Materials and Methods: This cross-sectional study was conducted in a large food industry in 2021. The sample size in this study was calculated as 231 individuals using Cochran's formula with an accuracy of 0. 05. The studied variables included two groups of reactive (safety training, risk assessment, and control) and reactive (type of accidents, unsafe conditions, and acts) performance indicators, as well as the final safety performance index. The numerical range of this index was 0. 2 to 5. 0. Results: The final safety performance index was evaluated as 1. 76 in this food industry. The results revealed that the amount of six groups of safety performance indicators including risk assessment (4. 01), risk control (3. 93), safety training (3. 85), type of accidents (2. 47), unsafe acts (2. 17), and unsafe conditions (2. 05) were respectively estimated in this industry. In addition, the lowest and highest indicators were related to unsafe equipment (0. 13) and use of personal protective equipment (2. 09), respectively among the 32 evaluated indicators. Conclusion: The findings of the study indicated that although the level of safety performance in this food industry is not unfavorable, practical and beneficial measures should be implemented in line with the six groups and 32 indicators to achieve a favorable safety performance index.

Background and Objective: This study aimed to provide a risk assessment method based on a Fuzzy Bayesian Network (FBN) to prevent the failure of firefighting systems (FSs). Materials and Methods: In this research, the fault tree structure was validated, and the failure factors were identified. Triangular fuzzy numbers and the combined CoA/Sum-Product method were used to calculate the failure rate. Subsequently, deductive and inductive reasoning, as well as sensitivity analysis were performed using fuzzy logic and fault tree transmission in a Bayesian Network (BN). Results: The results of a case study on methanol storage tanks showed that the combination of FBN and validation of structures can be presented as a suitable method to evaluate the reliability of FSs. The content validity index of the final basic events was over 0. 79. The highest and lowest failure rates were related to the foam system and valve, respectively. Moreover, the failure rate for the failure of FSs was 5. 7×10-6 based on the fuzzy fault tree (FFT). After updating with BN, the previous rate of failure of FSs with FBN was calculated to be 0. 022978, which was greater than the value of the FFT. The reliability of the system was equal to 0. 77022. Conclusion: The present approach can help the decision-making process of managers and analysts of the petrochemical industry to prevent the failure of FSs in tanks due to changes in systems.

Background and Objective: Human error is the leading cause of accidents in industries. The present study aimed to evaluate the safety culture and model the factors affecting it in a process industry using the structural equation modeling method. Materials and Methods: In this cross-sectional study, safety culture was assessed using a 10 dimensions' questionnaire constructed by researchers with a Likert scale. This study was conducted in the petrochemical industry in 2021. Questionnaires were distributed among 312 employees, and 308 questionnaires were completed. SPSS 23. 0 and AMOS 23. 0 were used for data analysis. Results: The safety culture score was calculated at 3. 35. The results of SEM demonstrated that the factor loadings of the effect of income, education, and work experience on safety culture were 0. 322, 0. 445, and 0. 328, respectively, and the factor loadings of the effects of education, work experience, and age on accident experience were-0. 336,-0. 312, and-0. 214, respectively. The relationship between safety culture and accident experience had a factor loading of-0. 477, and GFI was obtained at 0. 97. Conclusion: The results of the safety culture assessment indicated that this organization had a positive safety culture, with a high score being related to the dimensions of utilizing protective equipment, training and understanding of issues, and the commitment of managers and supervisors. The results of structural equation modeling revealed that education, income, and work experience all had a positive impact on safety culture. Accident experience was inversely related to such factors as age, education, and work exper ience, and safety culture was likewise inversely correlated with accident experience.

Background and Objective: A proper safety culture is one of the important factors that ensure a healthy and safe work environment. In order to ensure safety performance in the workplace, healthcare departments are required to establish safety rules and procedures and ensure they are applied throughout the organization. Therefore, the present study aimed to investigate the safety culture among healthcare workers (HCWs) in Borujerd. Materials and Methods: This cross-sectional-analytical study was conducted on 452 HCWs in Boroujerd (1400-1401). Study subjects were selected by random stratified sampling method. The standard safety culture questionnaire was used to assess safety culture. The linear regression was used in SPSS (version 22) to identify factors related to safety culture. Results: The mean age of the study subjects was 33. 97±, 5. 69 years, and most of them were female (58%). The mean score of safety culture was 172. 64±, 23. 53,moreover, 7. 1% and 92. 9% of subjects had a negative and positive safety culture, respectively. Linear regression analysis demonstrated that the overall score of safety culture decreases with an increase in age. The overall score of safety culture in the occupational group of discharge and income and guards was lower than in the radiography group, and it was higher in participants with illness and accident history than in those without illness and accident history. Conclusion: As evidenced by the obtained results, the safety culture in the HCWs in this study was at a high level. The variables of age, history of accidents, illness, and occupation are the factors influencing the safety culture score.

Background and Objective: Lower back pain is one of the most common musculoskeletal disorders and an important cause of early retirement due to disability in employees in industrialized and developing countries. The present study aimed to determine the work ability index and its relationship with low back pain among employees of the Tehran offset printing industry. Materials and Methods: This cross-sectional descriptive-analytical study was performed within six months in 2020. Data from 220 employers working in the offset printing industry were collected through survey questionnaires, including Nordic Musculoskeletal Questionnaires and Work Ability Index. Data analysis was performed using SPSS software (version 24) with a significance level of p<0. 05. Results: In general, more than half of the participants (62. 5%) indicated high symptoms of lower back pain. The results of the Pearson correlation test showed that there was a positive and significant correlation between the level of work ability and the severity of low back pain (p<0. 001). Conclusion: The results of the present study indicated the need to increase awareness through training courses, and identify and control the risk factors that cause back pain in the studied employees to strengthen appropriate practices and create motivation in adopting appropriate preventive measures to reduce the prevalence of back pain and increase the work ability.

Background and Objective: Work stress is a negative physical and mental reaction that is the second most common work-related problem after musculoskeletal disorders. Fatigue is a state that occurs during a work period and causes a person to lose efficiency. This study was thus conducted to determine the relationship between job stress and job fatigue in nurses. Materials and Methods: It was a cross-sectional descriptive-analytical study conducted in teaching and therapeutic hospitals of Gorgan, Iran, including Sayad Shirazi Hospital, 5 Azar Hospital, and Taleghani Hospital in 2021. A total of 277 nurses were included in the study after random stratified sampling. Data were collected by the OSIPOW job stress questionnaire and the Swedish SOFI job fatigue questionnaire and analyzed by the SPSS software (version 23). Results: The mean score of job tension was 180. 05±, 23. 4, which was classified as moderate to severe. The highest score was related to the role of the workload dimension and the lowest to the physical environment dimension. The mean score of job fatigue was 53. 18±, 22. 5 and was evaluated at a lower-than-average level. The highest score was related to the dimension of lack of energy and the lowest to the dimension of physical ef fort. There was also a weak direct and significant relationship between job tension and job fatigue, as well as all its dimensions. Conclusion: Considering the relationship between job stress and job fatigue, it is suggested to provide the necessary infrastructure and facilities to reduce stress in nurses and provide training on how to deal with stress to the hospital staff.

Background and Objective: COVID-19 spread faster in crowded public places,therefore, industrial workers are more prone to COVID-19 infection. The present study aimed to evaluate the prevalence of COVID-19 and its association with adherence to sanitary protocols in detergent industries in Alborz province, Iran. Materials and Methods: Given a 95% confidence interval, a 3% permissible error level, and an 11% prevalence rate, a total sample of 552 from seven industrial units were recruited. Demographics and COVID-19 infection data were gathered using a questionnaire. The level of adherence to sanitary protocols was assessed using a checklist approved by the Ministry of Health. Results: The average age of the subjects was 35. 17±, 7. 27 years, and 14. 3% were female. The level of adherence to sanitary protocols was 94. 36±, 6% in each industry. The prevalence of COVID-19 infection was 33. 5% in detergent industries, with the highest rate in the packaging unit (42%). The results suggested that COVID-19 prevalence was associated with education level, history of an infected family member, exposure to crowded places, and disinfection (P<0. 05). Conclusion: The contact history of workers with an infected family member played a significant role in their COVID-19 contraction. Enhancing air-conditioning systems, social distancing in working stations, evaluating the workers with a history of contact with infected family members, and developing management measures, including educating workers' families, quarantining, and granting leave to workers in contact with infected family members, are integral for the prevention and control of the epidemic in industries.