Investigating the effect of workplace noise exposure on cardiovascular disease risk factors in a power plant industry: A case-control study.

BACKGROUND: Occupational noise exposure is a significant health problem. In addition to hearing impairments, noise as a stressor may cause cardiovascular problems. OBJECTIVE: This study aimed to investigate the effect of exposure to workplace noise on cardiovascular disease risk factors. METHODS: This case-control study was conducted in 2021 in a power plant in Iran. In this study, the health status of 406 employees in both exposed (n = 203) and non-exposed (n = 203) to noise groups was examined for cardiovascular disease risk factors. Also, the trend of changes in the studied variables from 2012 to 2020 in exposed employees was examined. Data were collected from participants' annual physical examinations and occupational noise exposure measurements. To measure the noise in the present study, the KIMO-DB300 noise level meter was used. Data were analyzed in SPSS-26 software. RESULTS: The results revealed that mean fasting blood sugar (FBS), triglyceride, liver enzyme (SGOT), blood pressure, and body mass index were significantly different in the two groups (p-value<0.05). There was no significant difference in the mean of creatinine, cholesterol, and liver enzyme (SGPT) between the two groups (p-value>0.05). In the exposed group, the mean of all studied variables except diastolic blood pressure was statistically different during the study years (p-value<0.05). CONCLUSION: This study demonstrates that exposure to noise above the permissible level can affect the cardiovascular disease risk factors, so it is recommended to apply engineering and management measures like using Hearing Conservation Programme (HCP) to reduce the risk of these diseases with periodically assessing the health status of employees and timely diagnosis.

Development of an ergonomics management model in the workplace: Introduction of the TUGA ergonomics management and analysis model (TEMA).

BACKGROUND: Conducting practical studies in ergonomics requires attention to all aspects of ergonomics with a comprehensive approach and focus on continuous improvement cycles. OBJECTIVE: This study aimed to develop and present an ergonomics management model in the workplace. METHODS: This study was performed using a three-stage Delphi study with 30 experts and a fuzzy analytical hierarchy process. According to the literature review and experts' opinions, the general cycle of the ergonomics management system with eight steps was developed. New methods were formed in two of these eight steps: the 3rd step (developing an ergonomic evaluation method) and the 5th step (creating a cost-benefit evaluation method). RESULTS: The eight implementation steps of the TEMA were determined as follows: 1) Performing task analysis (TTA), 2) Ergonomic hazard identification, 3) Estimating the ergonomic index, 4) Determining control measures, 5) Evaluating cost-benefit parameter, 6) Implementing control measures, 7) Continuous monitoring, and 8) Evaluating the effectiveness of control measures. The Delphi study revealed that the number of deleted parameters includes one item (burnout), and the remaining parameters were 16 items. The mean CVI and CVR values were 0.92 and 0.80, respectively. Cronbach's alpha values for each of the physical, environmental, and cognitive components and the entire model were 0.91, 0.87, 0.85, and 0.89, respectively. CONCLUSION: Using the mentioned management model can be a practical step towards properly evaluating the most critical dimensions of ergonomics in the workplace and optimal planning to implement control measures to establish a dynamic management system to reduce ergonomic risk factors in the workplace.

Development of a novel ergonomic index assessment in the workplace based on physical, cognitive, and environmental components.

BACKGROUND: Currently, proper assessment of the existing ergonomic hazards, focusing on improving the health of individuals, is of great importance. OBJECTIVE: This study aims to develop a new model for ergonomic index assessment in the workplace, focusing on physical, cognitive, and environmental components. METHODS: To determine the parameters to be measured for each group of occupations, the most critical indicators in each ergonomic dimension were identified using a review of scientific texts and obtaining expert opinions. The opinions of 30 experts were studied in three stages Delphi study. Cronbach's alpha was used to calculate model reliability in SPSS version 25. An analytical hierarchy process was used to determine the weight values of each component and parameter. The weights were calculated in Expert Choice version 11. RESULTS: The mean CVI and CVR values were 0.92 and 0.80, respectively. Cronbach's alpha values for each of the physical, environmental, and cognitive components and the entire model were 0.91, 0.87, 0.85, and 0.89, respectively. Physical components and parameters of physical condition during work, mental workload, lighting, and thermal stress in the workplace were among the most important parameters in the three groups of office, operational, and services jobs. CONCLUSION: The model can be a practical step toward properly evaluating the ergonomic components and planning to implement control measures to reduce physical, cognitive, and environmental risk factors. Considering the study of different variables in occupational ergonomic risk assessment, this model can be a helpful tool in ergonomic management systems used in different occupational environments.

Evaluating the potential severity of biogas toxic release, fire and explosion: consequence modeling of biogas dispersion in a large urban treatment plant.

Objectives. Biogas production in treatment plants for energy generation has increased in recent years. This study aimed to model the consequence of biogas release in a large urban treatment plant. Methods. The study modeled biogas storage tank consequences in a large urban treatment plant in Iran. Due to potential for biogas harmfulness, three consequences of toxic release, fire and explosion were evaluated. Scenarios were evaluated in the worst-case situation. All modeling steps were performed using PHAST version 7.2. Results. In the case of catastrophic reservoir rupture in summer, distances of 3788.94, 128.86 and 91.72 m from the reservoir in the wind direction will be in the range of 100, 500 and 1000 ppm biogas, respectively. Study of pressure values due to explosion in the catastrophic rupture scenario revealed that distances of 57.19, 14.70 and 115.84 m from the biogas reservoir were in the range of 0.02, 0.13 and 0.2 bar pressure increase, respectively. Conclusion. Due to the treatment plant's location in a dense urban area, biogas dispersion could lead to exposure of many people to high-risk areas. Therefore, taking control measures comparable with the consequence modeling output can be a practical step toward reducing vulnerability against such incidents.