Abstract
Background: Silica exposure has remained a severe public health threat to millions of workers worldwide. Silica exposure and silicosis are health hazard and risk, respectively, that has also been recognised in South Africa. There are limited studies which have investigated factors that influence silica exposure within the railway railroad environment. Objectives: To examine the factors that influence silica dust exposure in South African rail industries from 2008 to 2018. Methods: A descriptive cross-sectional study was conducted to investigate the relationship between silica exposures and type of activities, duration of activities, environmental conditions and existing engineering controls. Silica exposure data from Occupational Hygiene reports for the period 2008 to 2018 were collected using a data abstraction form. Logistic regression models were used to analyze data using SPSS version 25. Results: Participants in the study were 475, of which (50.8%) worked full-time. in this study. Rail maintenance participants were more likely to have >10% Occupational Exposure Limit (OEL) of exposure to silica, crude odd ratios (OR) 3.38: 95%CI (2.34 – 4.89) as compared to other occupations, while participants doing Ballast offloading had OR=2.84: 95%CI (1.60 – 5.02). Participants who performed occupational activities daily compared to once a month were less likely to have >10% OEL exposure to silica OR: 0.12 95%CI (0.04 – 0.44), and AOR 0.11 95% CI (0.03 – 0.43). For the duration of work, participants who worked 9 hours compared to 8 hours were more likely to have >%10 OEL silica exposure OR 1.64 95% CI (1.12 – 2.40). Participants performing outdoor activities were more likely to have >10% OEL silica exposure OR 3.53 95% CI (1.76 – 7.06). Participants who used Personal Protective Equipment (PPE) controls, were more likely to have >10% OEL silica exposure compared to Engineering controls, OR 8.23 95% CI (3.83 – 17.66) and those who identified “raining” weather were less likely to have >10% OEL silica exposure OR 0.03 95% CI (0.01 – 0.23). Conclusion: The study revealed that the employment category, occupation type, occupational activities, frequency of activities, duration of work and types of existing controls all impact employees’ exposure to silica at the rail industry in South Africa. The results emphasise the need to keep exposure minimal and monitor these factors at workplaces to keep silica exposure as low as possible.
M.A. (Public Health)