Structural Modeling of Safety Performance in Construction Industry

Background: With rapid economic development and industrialization, the construction industry continues to rank among the most hazardous industries in the world. Therefore, construction safety is always a significant concern for both practitioners and researchers. The objective of this study was to create a structural modeling of components that influence the safety performance in construction projects. Methods: We followed a two-stage Structural Equation Model based on a questionnaire study (n=230). In the first stage, we applied the Structural Equation Model to the proposed model to test the validity of the observed variables of each latent variable. In the next stage, we modified the proposed model. The LISREL 8.8 software was used to conduct the analysis of the structural model. Results: A good-fit structural model (Goodness of Fit Index=0.92; Root Mean Square Residual=0.04; Root Mean Square Error of Approximation=0.04; Comparative Fit Index=0.98; Normalized Fit Index=0.96) indicated that social and organizational constructs influence safety performance via the general component of the safety climate. Conclusion: The new structural model can be used to provide better understanding of the links between safety performance indicators and contributing components, and make stronger recommendations for effective intervention in construction projects

Development and Evaluation of a New Questionnaire for Rating of Cognitive Failures at Work

Cognitive-based human errors have major contribution to performance and safety in working environment. This study designed to develop a measurement tool in order to evaluate this type of errors in the occupational settings. An Occupational Cognitive Failure Questionnaire (OCFQ) was developed. Content validity of the OCFQ was performed using a quantitative approach. Reliability of questionnaire was assessed by internal consistency and test-retest methods. A preliminary list of 35-items was prepared as a starting point. After evaluation of validity, five items were rejected. The new measurement instrument with 30-items was finally developed. The content validity index (CVI) for the final OCFQ was found acceptable (CVI=0.7). Results show that final OCFQ was internally consistent (α=96) and intraclass correlation coefficients (ICC) was 0.99. Measurement of cognitive failure in the workplace requires a valid and reliable tool. In respect to probable outcomes of cognitive failures occurrence at work, the present study suggested that OCFQ would be a useful instrument for measurement of cognitive failure in the working environment

Mental workload and its relation with fatigue among urban bus drivers

Introduction: Driving crash is one of major&nbsp;concerns in all countries. Mental workload reflects the level of attention resources required to meet both objec&shy;tive and subjective performance criteria, which may be affected by task demand, external support, and past experience. Mental workload has been commonly cited as a major cause of workplace and transportation accidents. The objective of this study was assessment of mental workload and its relation with fatigue among urban bus drivers in Tehran, Iran. Methods: In this descriptive and analytical study, the NASA-TLX workload scale and the Samn-Perelli fatigue scale were completed by 194 professional bus drivers. Descriptive statistics as well as correlation and regression analysis were performed for data processing. Results: The total mental workload had highest correlation with the physical demand(r=0.73, p<0.001), the mental demand (r=0.68, p<0.001) and the time pressure (r=0.58, p<0.001). The total fatigue perceived by bus driver had highest correlation with the frustration level (r=0.42, p<0.001), the time pressure (r=0.24, p<0.001) and the mental workload (r=0.21, p<0.001). Conclusion: Mental workload, physical workload and time pressure are important determinants of the total mental workload and fatigue perceived by urban bus drivers. A comprehensive intervention program, include work turnover, trip and work-rest scheduling as well as smoking cessation, was recommended to improve mental workload and fatigue.&nbsp

Inter and intra-rater reliability of a new assessment tool for Health٫ Safety, and Environment (HSE) in urban districts: a case study in Tehran city

Introduction: In recent years, a growing attention has been paid to assess the physical characteristics of rich and poor urban districts to understand social health differences. Urban districts environment play a major role in health of the residents. Previous few studies have considered some aspects of limited neighborhood environment. The current study was designed to investigate the reliability of the Neighborhood Health, Safety and Environment (NHSE) tool in one of Tehran city neighborhoods. Material and Method: Dimensions and related items of the NHSE were extracted based on the previous studies and interviews with city experts. Five observers completed the NHSE in a selected neighborhood in order to test inter and intra-rater reliability of the tool. Data analysis was done using the Cronbach&rsquo;s alpha, Interclass Correlation Coefficient (ICC) and kappa coefficient. Result: The ICC and Cronbach&rsquo;s alpha were estimated 0.86 for all dimensions of the NHSE. The calculated kappa values were in the range of 57%-66% for inter-rater reliability and 0.47-0.62 for intra-rater reliability. Conclusion: The NHSE tool was shown to have a desirable inter and intra-rater reliability and a good level of internal consistency for assessing the health, safety, and environment (HSE) of the neighborhoods

Human-based dynamics of mental workload in complicated systems

As a dynamic system in which different factors affect human performance via dynamic interactions, mental workload needs a dynamic measure to monito r its factors and evidence in a complicated system, an approach that is lacking in the literature. The present study introduces a system dynamics-based model for designing feedback mechanisms related to the mental workload through literature review and content analysis of the previous studies. A human-based archetype of mental workload was detected from the data collection process. The archetype is presented at various stages, including dynamic theory, behavior over time, leverage points and model verification. The real validation of the dynamic model was confirmed in an urban train simulator. The dynamic model can be used to analyze the long-term behavior of the mental workload. Decision-makers can benefit from the developed archetypes in evaluating the dynamic impact of their decisions on accident prevention in the complicated systems

Factors Influencing Unsafe Behaviors and Accidents on Construction Sites: A Review

Objective. Construction is a hazardous occupation due to the unique nature of activities involved and the repetitiveness of several field behaviors. The aim of this methodological and theoretical review is to explore the empirical factors influencing unsafe behaviors and accidents on construction sites. Methods. In this work, results and findings from 56 related previous studies were investigated. These studies were categorized based on their design, type, methods of data collection, analytical methods, variables, and key findings. A qualitative content analysis procedure was used to extract variables, themes, and factors. In addition, all studies were reviewed to determine the quality rating and to evaluate the strength of provided evidence. Results. The content analysis identified 8 main categories: (a) society, (b) organization, (c) project management, (d) supervision, (e) contractor, (f) site condition, (g) work group, and (h) individual characteristics. The review highlighted the importance of more distal factors, e.g., society and organization, and project management, that may contribute to reducing the likelihood of unsafe behaviors and accidents through the promotion of site condition and individual features (as proximal factors). Conclusion. Further research is necessary to provide a better understanding of the links between unsafe behavior theories and empirical findings, challenge theoretical assumptions, develop new applied theories, and make stronger recommendations

Health, Safety and Environment (HSE) assessment of neighborhoods: A case study in Tehran Municipality

Urbanization is growing rapidly in recent centuries. This phenomenon can cause many changes in various aspects of human life including the economy, education and public health This study was conducted to assess the Health, Safety and Environment (HSE) problems in Tehran neighborhoods. A new instrument was developed based on the results of a literature review and formulated during a pilot study. Through cluster sampling, 10 neighborhoods were selected based from 374 neighborhoods of Tehran. Six observers completed observational items during the field studies. Secondary data were used to obtain non-observation characteristics. Standard descriptive statistics were used to compare the HSE characteristics in sampled neighborhoods. Furthermore, control chart was used to as a decision rule to identify specific variation among sampled neighborhoods. Niavaran neighborhood had the best HSE status (52.80%±25.03) whereas Khak Sefid neighborhood had the worst one (20.09%±27.51). Standard deviations of HSE characteristics were high in different parts of a neighborhood. Statistical analysis indicated that significant differences in HSE characteristics exist among sampled neighborhoods. HSE status was in warning situation in both rich and poor neighborhoods. Community-based interventions were suggested as health promotion programs to involve and empower people in neighborhoods

Executive and hierarchical models for participatory response to health emergencies in the workplace: Lessons from COVID-19

Introduction: Workplaces are high-risk environments for epidemic transmission, and the COVID-19 pandemic has highlighted the significant impacts that health emergencies can have on both the healthcare system and the economy. This study presents executive and hierarchical models for participatory response to health emergencies in the workplace, with a focus on COVID-19. Methods: The study was conducted in three phases. Content analysis of interviews with 101 stakeholders and national documents was used to identify key themes and dimensions for an executive model. A focus group discussion and review of international documents were then used to refine and expand the executive and hierarchical models. The alignment and trustworthiness of the final models, as well as feedback, were gathered from 117 informants working in various workplaces. Results: The executive model highlighted that context understanding, management commitment, and participation play critical roles in developing tailored prevention and response plans, and adequate support is necessary for successful plan implementation. Monitoring and review processes should be established to ensure proper functioning. The hierarchical model emphasizes the need for collaborative efforts from various stakeholders to effectively implement pandemic prevention and participatory response plans. Conclusion: Overall, the executive and hierarchical participatory models presented in this study provide a framework for effectively controlling pandemics and other health emergencies in the workplace, enhancing both health resilience and the sustainability of economic activities