Journal of Health and Safety at Work

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Introduction: Individuals’ jobs performance is one the most important factors in industries and organizations. The aim of the present study was to investigate the simultaneous effect of exposure to noise, lighting and heat stress on the workers’ job performance.
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Material and Method: In this analytical-descriptive study, 30 employees of the auto parts manufacturer, in Tehran city, were chosen by simple random sampling. By controlling and limiting confounding factors, the simultaneous effect of noise, lighting and heat stress on the participants’ job performance was investigated, using tow series of mental and manual testes. Data were analyzed by SPSS software version 18, using descriptive statistic, ANOVA and Tukey testes and also person correlation coefficient.
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Result: The results showed that by increasing the noise and heat stress (P = 0.046, r=0.344) and decreasing of lighting (P =0.008, r = -0.472), the required time for performing the Minnesota placement test has been gone up. Moreover, the result revealed that by increase in noise and heat stress (P = 0.007, r = 0.478) and decrease in lighting (P=0.003, r = 0.523) the required time for competing hand tool dexterity test has been also increased at surface and mid level.
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Conclusion: Finding of the present research manifested that increase in noise and heat stress and also reduction in lighting lessen the speed of manual tests and time and accuracy of mathematical calculations. Therefore this result confirm the effects of various environmental factors on individuals’ job performance, in a way that by variation of different environmental factors, time of manual test and time and accuracy of mental tests would be changed.

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Introduction: IBioaerosols are usually defined as aerosols or particles with microbial, plant or animal origin. Textile industries are of the working environments in witch workers are exposed to bioaerosols. In textile industry, the highest contamination concentration is the belonged to carding step. Since, textile industry in iran is native and a large number of employers are working in this industry, this study was undertaken to assess bacterial bioaerosols concentration in a textile in industry in iran.
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Material and Method: In cross-sectional study was done in different units and also outdoor environment of a cotton textile plant. The concentration of bioaerosols were sampled and measured according 0800 method presented by NIOSH, during summer. Diagnosis of type of colonies and bactories, grown on blood agar, was done using gram staining.
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Result: The mean bioaerosols concentration obtained the highest and lowest values in outdoor environment (94±9.5 CFU/m3) and unit 2 (Ring site) (64±18.0 CFU/m3), respectively. The mean difference of bioaerosols concentration in unit 1 (Carding sites) and unit 2 (Ring site), was statistically significant in this study. The highest number of bioaerosols colony was for staphylococcus Epiderms (N=1743) and the lowest number was for streptococcus pneumonia (N=64) in the whole plant.
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Conclusion: Although the bioaerosols concentration obtained in the present study is lower than those reported in other studies, these values are above the threshold recommended.

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Introduction: To evaluate heat stress in the workplace different indices are used. But, none of these measures have been widely accepted. The aim of this study was to determine effective criteria in selecting a heat stress index and weighting of these criteria.

Material and Method:  This study is a qualitative study that was designed and conducted within 10 stages. In the current study, effective criteria for choosing a heat stress index was determined by using Delphi technique and expert’s opinions (30 people), and then the fuzzy analytic hierarchy process was used for weighting and prioritization of these criteria.

Results: Analyzing the completed questionnaires by the experts and according to the percentage of respondents, 11 criteria were finally selected. “Simplicity” criteria by %76.6 had the highest percentage of response. But, the relative weight of this criteria was 0.041, and had the lowest weight after the “low cost” criteria.  The criteria relating to the “Standard” item was 0.141as the highest relative weight.

Conclusion: It can be concluded that the first step to have a reliable and accurate measurement is to choose a proper and correct index. Based on specialists and expert’s opinions, standardization of the index is the most important selection criteria. Other criteria that must be considered were accuracy, reliability and good correlation with the physiological strain indices.

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Introduction: Heat stress is caused by many factors such as individual factors, environmental factors, and management factors. Individual risk factors can decrease the heat tolerance, and play an important role in heat stress disorders incidence. The aim of this study was to review individual parameters influencing the thermal stress and review the preceding studies.

Material and Method: In this review study sites such as Web of Science, Scopus, Pubmed, Iran Medex, Magiran, Google Scholar and SID databases were used for search. The keywords included heat stress, personal factors and heat exposure. The period of 1995 to 2015 was investigated, and finally 75 original articles were identified.

Result: At the individual level, exposure with a single risk factor may reduce the workers’ heat tolerance; while exposure with a combination of several risk factors probably synergistically increases the risk of heat-related disorders. Individual risk factors include age, gender, obesity, fatigue, race, and previous heat disorders and dehydration. In addition, some diseases (such as cardiovascular disease, diabetes and infectious diseases) or use of certain drugs or alcohol can reduce the heat tolerance.

Conclusion: It is necessary to pay attention to the mentioned items when selecting workers in the hot environments. Also, due to the lack of awareness and knowledge of workers, it is necessary to provide appropriate training programs to reduce the effects of heat stress.

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Introduction: Disasters, incidents and crises are complex and controversial issues for the industries and organizations. Organizational resilience is an effective goal that continuously helps the organization’s performance throughout business, disasters and critical situations. Therefore, the present study aimed to investigate the validity and reliability of organizational resilience questionnaire in dealing with major accidents.
Material and Method: The present study was a descriptive-analytic study. At first, the concept of organizational resilience and its dimensions were determined for the review. Then, for evaluating the content validity, the designed questionnaire was distributed among members of the expert’s panel and the Content Validity Index (CVI) and Content Validity Ratio (CVR) were calculated based on the comments. The reliability of the questionnaire was determined after completing it by 272 employees of the studied industries.
Result: The CVR was higher than the standard value (0.50) considering all items. Also, all dimensions of the questionnaire, except for the responsibility dimension the CVI’s were above 90%. Cronbach’s alpha coefficient for all questionnaire dimensions except for the responsibility dimension was higher than the acceptable value (0.70). This coefficient for the whole questionnaire was 0.967 indicating that this index was in excellent level.
Conclusion: The findings showed that the organizational resilience questionnaire in dealing with major accidents had an acceptable validity and reliability and in order to examine the organizational resilience in organizations, it could be used as a comprehensive, strong and reliable tool.

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Introduction: The carpet industry is one of the most important handicrafts in Iran. This industry is one of the most difficult and harmful professions, in which the employees are often working in a workplace with non-ergonomic, unsafe, and unhealthy conditions. The present study aimed to address the modeling of the individual, job characteristics, and workplace conditions with the general health of carpet weavers through an ergonomic approach.
Material and Methods: The current study was a descriptive-analytic survey. The study population was female workers, who have had a minimum of one-year work experience and working in the workshops located in Meshginshahr city villages. The data collection tool was a combination questionnaire including, Goldberg’s questionnaire (GHQ-28), NIOSH questionnaire (disease history section), and questions about workplace conditions. The obtained data were entered into SPSS-17 software and analyzed statistically using statistical modeling based on the general linear model, multivariate and other statistical tests.
Results: Unpleasant condition was observed among the 37.4% of the examined, in terms of general health. Logistic regression modeling was used to investigate the internal and external factors of carpet weavers with their general health status. According to the model, general health has a significant relationship (p<0.05) with most of the internal factors such as age, marital status, history of disease, etc. However, there was no significant relationship with the workplace conditions.
Conclusion: According to the results of this study, it can be concluded that demographic and job variables are of the most important factors affecting the general health of carpet weavers. Although in the model, the workplace conditions did not show any significant relationship with the components of general health, interpreting these findings requires more studies. More studies are required objectively to identify the effect causes of the general health of carpet weavers (especially workplace conditions).

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Introduction: Individual work performance (IWP) plays a crucial role in both organizational effectiveness and employee well-being. To address the limitations of existing job performance questionnaires, the Individual Work Performance Questionnaire (IWPQ) was developed based on a holistic and systematic framework. This study aimed to translate, culturally adapt, and evaluate the psychometric properties of the Persian/Farsi version of the IWPQ.
Material and Methods: This descriptive methodological study was conducted in two stages: (1) translation and cultural adaptation (assessment of face and content validity), and (2) psychometric evaluation (assessment of internal consistency, test-retest reliability, and construct validity). The sample consisted of 206 administrative employees with a mean age of 34.29 years (SD = 7.66) and an average work experience of 8.48 years (SD = 7.39). The IWPQ was translated using forward and backward translation methods, and its validity was evaluated using exploratory and confirmatory factor analyses.
Results: The Persian IWPQ demonstrated acceptable face and content validity. Exploratory factor analysis confirmed a three-factor structure: task performance, contextual performance, and counterproductive work behavior. Confirmatory factor analysis indices (e.g., CFI = 0.87, SRMR = 0.08 and RMSEA = 0.09) indicated a approached model fit acceptability. Internal consistency and test-retest reliability were satisfactory across all dimensions (Cronbach’s alpha > 0.70 and ICC > 0.80).
Conclusion: The Persian version of the IWPQ is a reliable and valid instrument for assessing individual work performance across diverse occupational groups. It provides a valuable resource for evaluating workplace interventions and strategies aimed at enhancing performance.

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Introduction: Unsafe acts are one of the main causes of workplace accidents. Given the critical role of the steel industry in our country, and the limited research on human factors, and the importance of identifying the contributors to accidents, this study was conducted with the aim of identifying human factors influencing accidents and unsafe behaviors using the Human Factors Analysis and Classification System (HFACS). The identified factors were then prioritized using the Decision-Making Trial and Evaluation Laboratory (DEMATEL) and Analytic Network Process (ANP) methods. Based on the results, appropriate recommendations were proposed for the prevention of accidents and the reduction of unsafe acts.
Material and Methods: This descriptive-analytical study was carried out in the rebar production unit of a steel manufacturing plant. Among 35 recorded accidents over the past two years, 28 were related to the rebar production unit. Data were collected through review of accident reports, seven on-site observations during high-risk shifts, and interviews with employees. After analyzing the occupational accidents, the rebar production process in the rolling unit was identified as a high-risk area. The HFACS checklist was used to assess this process and classify the human factors contributing to accidents. Subsequently, DEMATEL and ANP methods were applied to determine causal relationships and prioritize the factors.
Results: The HFACS analysis identified 236 human factors, among which the preconditions for unsafe acts and organizational factors had the highest frequency (24.57% each), while external factors had the lowest (8.47%). According to DEMATEL results, organizational influences exerted the greatest impact on other levels, whereas external factors had the least effect. In terms of being influenced by other levels, unsafe acts showed the highest level of susceptibility, whereas unsafe supervision had the lowest levels. Based on ANP findings, the preconditions for unsafe acts had the highest importance, while unsafe supervision had the lowest in contributing to unsafe acts.
Conclusion: The findings of this study suggest that improving safety culture, improving organizational regulations, implementing targeted training programs, and updating equipment can play a significant role in reducing accidents caused by unsafe acts. The results provide practical insights for managers and policymakers and can serve as a useful tool for decision-making in occupational health and safety within the steel industry.