Development of a framework for the protection of quarry and allied workers from occupational respiratory infections in Namibia.
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Date
2025
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Publisher
Namibia University of Science and Technology
Abstract
Background: Workplace frameworks ensure compliance with fundamental Occupational Health and Safety (OHS) legal provisions, effectively reducing workplace accidents and illnesses. Namibia lacks a comprehensive respiratory framework for protecting high-risk workers in quarry and allied industries. This study aimed to develop a respiratory protection framework that safeguards quarry and allied workers who are susceptible to occupational respiratory diseases in Namibia.
Methodology: A phased methodological approach was adopted in the study, which involved mixed methods (qualitative and quantitative) experimental techniques and secondary data review. Phases 1 and 2 assessed existing respiratory protection practices by quarry and allied workers and their knowledge, attitudes, and practices on occupational respiratory protection, respectively. This was conducted through self-administration of 320 questionnaires to workers, using a multi-tier sampling technique, as well as interviewing the managerial staff. Phase 3 involved a laboratory assessment of the Particle Filtration Efficiency (PFE) of N95 masks used by the workers. Phase 4 reviewed the Namibian legal provisions aligned with respiratory protection. Premised on the study findings, a respiratory protection outline was proposed, addressing gaps in policy and practice in phase 5.
Results: Characteristics and variables such as age, gender, work experience, beards, level of education, knowledge (training) of respiratory protection hazards, and risk perceptions of respiratory protection exacerbate the workers' risk of respirable dust inhalation. Results revealed that about 69.7% of the quarry and allied workers currently experience respiratory protection. However, 66.8%, 57.2%, and 69.7% have inadequate respiratory protection knowledge, negative attitudes, and poor protective practices, respectively. Three (3) themes were identified: One (1). Employee knowledge of respiratory protection. Two (2) Employee attitudes aligned with respiratory protection and three (3) Employee practices on respiratory protection. The Particle Filtration Efficiency (PFE) gravimetric weighing had minimal dust retention, with higher dust exposure at Sites C, D, F, and G. Particle size analysis revealed that most masks failed to effectively filter smaller particles below PM10. Reduced mask efficacy due to membrane saturation was also recorded after prolonged use. Sites A, B, and C demonstrated PM10 particle retention at 100%, while Site D showed only 60%. The review of Namibian legal provisions protecting quarry and allied workers showed fragmentation and no clarity on implementation, thereby ineffectively protecting the workers. Guidelines to operationalise the framework were developed based on the study findings obtained through questionnaires from workers, interviews from management, Particle Filtration Efficiency (PFE) experiment results, and the review of Namibian legal provisions. The framework was evaluated by experts in academia, occupational health professionals, and industry stakeholders to assess each framework component's relevance, clarity, and completeness.
Conclusion: This study underscores substantial gaps in respiratory protection, knowledge, attitudes, and practices among quarry and allied workers in Namibia, contributing to increased exposure to
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respirable dust and associated health risks. The inefficacy of the N95 masks used by workers in filtering fine particulate matter of Particulate Matter PM10 further emphasised the critical need for a robust respiratory protection framework. Furthermore, the fragmented and unclear legal provisions fail to offer adequate protection for high-risk workers. Based on these findings, the proposed respiratory protection framework provides a comprehensive approach to improving workplace safety through enhanced policies, effective training programmes, and the adoption of higher-efficiency respiratory protective equipment. Implementing this framework is crucial for safeguarding workers' health and ensuring long-term occupational safety in Namibia’s quarry and allied industries.
Description
A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy in Health Sciences in the Faculty of Health, Natural Resources, and Applied Sciences
Keywords
Framework, Occupational Health and Safety, Quarry and Allied Workers, Respiratory Protection, Particle Filtration Efficiency, Filters/Masks.
Citation
Shihepo, S. (2025). Development of a framework for the protection of quarry and allied workers from occupational respiratory infections in Namibia.