Journal of Health and Safety at Work

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Introduction: Workplaces often contain potential risks, such as exposure to toxic chemicals. Conducting a thorough health risk assessment helps employers recognize these dangers and implement necessary controls. In the 20th century, modern risk assessment frameworks began to be established with the rise of public health agencies.
Material and Methods: The present study is a narrative review. In order to obtain necessary information, Persian and English texts were searched in Web of Science, PubMed, Scopus, SID and Magiran databases. Keywords such as “health risk assessment”, “chemicals” and “nanomaterials” were used in this study.
Results: Both quantitative and qualitative health risk assessments play critical roles in occupational health, with each method providing different levels of depth and accuracy depending on the situation. EPA Model, Monte-Carlo Simulation, Physiologically Based Pharmacokinetic (PBPK) Modeling, Quantitative Structure-Activity Relationship (QSAR) Models, Probabilistic Risk Assessment (PRA), Life Cycle Impact Assessment (LCIA), and Biologically Based Dose-Response (BBDR) Models, are among the most important quantitative methods for assessing the health risk of chemicals. COSHH Model, ICCT Model, ICMM Model, Australian Model, and Romanian Model, are the most important qualitative methods for health risk assessment of chemicals. In addition to the quantitative and qualitative methods, semi-quantitative methods like Singapore Model, LEC Method, and SEP Model, have also been proposed for assessing the health risk of chemicals. The preference for qualitative over quantitative methods in the risk assessment of activities involving nanomaterials stems from substantial uncertainties, limited data availability, and the unique and complex behaviors of nanomaterials in the workplaces.
Conclusion: Overall, the evolution of health risk assessment methods reflects a continuous drive towards greater accuracy, reliability, and relevance. As we continue to innovate and expand our knowledge, the field is well-positioned to address the complex and evolving landscape of chemical and material risks, ensuring the protection of human health and the environment. 

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Introduction: Nanomaterials are widely applied across diverse scientific and industrial sectors; however, their emergence has introduced a new generation of occupational hazards for workers. Concurrent with discussions on the adverse effects of nanomaterials on human health, researchers have sought to develop methods for assessing occupational risks associated with these materials. Accordingly, this study aims to propose a general framework for the development of such methods.
Material and Methods: This is a critical analysis study designed to evaluate existing methods for assessing occupational risks related to nanomaterials and ultimately propose a modified framework for refining these methods. By examining current approaches and identifying their strengths and weaknesses, the authors have proposed an improved framework for occupational risk assessment of nanomaterials.
Results: The proposed framework is based on two key dimensions: “Severity/Hazard” and “Probability/Exposure.” The first dimension determines the potential risk level arising from exposure to nanomaterials, with the most critical factors being the intrinsic properties and toxicology of the nanomaterial itself, parent materials, and similar substances. The second dimension describes the likelihood and nature of exposure to nanomaterials during work activities, with the most influential factors being worker, job tasks, and workplace environment characteristics.
Conclusion: The lack of sufficient data and numerous uncertainties regarding bio-nano interactions make quantitative risk assessment (the traditional occupational health approach) difficult, less reliable, and in some cases unfeasible for nanomaterials—given current knowledge. Qualitative and semi-quantitative approaches, such as Control Banding, despite demonstrating positive aspects, have faced significant criticism. The framework-based method proposed herein appears capable of partially overcoming these challenges.

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Introduction: Safety in healthcare facilities is critically important for the health and well-being of employees, patients, and organizational effectiveness. In recent years, various studies have examined the relationship between leadership styles or approaches and safety performance as one of the indicators of safety promotion. The present systematic review examines the relationship between different leadership styles and the safety performance of employees in healthcare facilities to provide a better understanding of the positive or negative effects of leadership on safety and to suggest strategies for improving safety performance in healthcare facilities. 
Material and Methods: A search was conducted in Scopus, PubMed, and Web of Science (ISI) databases. Keywords related to leadership, safety performance, and healthcare employees were used. Studies published up to the end of 2024 were identified and reviewed in accordance with PRISMA guidelines.
Results: Nineteen relevant papers were selected and included in the study. During the review of studies, eleven leadership styles or approaches were identified in relation to safety performance in various healthcare facilities. These included transformational leadership, leader-member exchange leadership, leader safety priority communication and feedback, ethical leadership, empowering leadership, inconsistent and destructive leadership, transactional leadership, task-oriented leadership, authentic leadership, safety leadership, and servant leadership. All leadership styles except for inconsistent and destructive leadership had a direct or indirect positive effect on safety performance. Also, the largest number of studies (n=4) focused on transformational leadership style and leader-member exchange leadership.   
Conclusion: The selection of appropriate leadership styles can contribute to enhanced safety, a reduction in occupational incidents, and improving service quality in healthcare settings. The findings of this study highlight the importance of developing effective leadership styles and strengthening appropriate managerial approaches to improve safety in healthcare facilities.