Peak Expiratory Flow Rate (PEFR) is a safe, easy, quick test of lung function that is commonly applied in clinical and occupational health. PEFR values vary with physiological factors like age, height and sex, and hence the use of a reference equation is necessary to interpret the values accurately. This study aimed to determine PEFR and its correlates among sawmill workers in Osogbo, Nigeria, using the Fawibe reference equation for Nigerian adults. The study design used was descriptive cross sectional, comprising of 250 sawmill workers that were obtained by multistage sampling. PEFR was measured with the use of portable peak flow meter and highest of three measurements was recorded for each participant. The Fawibe equations that take into account age, sex, and height were used to calculate predicted PEFR values, and measured PEFR values were reported as % of predicted PEFR. Respiratory function Abstract was classified as normal (≥80% predicted) or reduced (<80% predicted). Associations between PEFR status and selected variables were assessed using chi-square tests, with statistical significance set at p<0.05. The mean observed PEFR among respondents was 437.1 ± 60.49 L/min, with 42.4% recording a reduced PEFR and 57.6% a normal lung function. The bivariate analysis demonstrated that gender (p = 0.040), regular participation in milling activities (p = 0.001), daily hours spent on milling (p = 0.029) and BMI (p = 0.001) were significantly associated with reduced PEFR. After standardization with the Fawibe reference equation, a significant number of sawmill workers had a reduced PEFR linked to specific demographic, anthropometric and/or occupational factors. The study underscores the importance of routine respiratory health monitoring and strengthening occupational dust control among workers exposed to wood dust.

Reference

 Adeoye, O. A., Adeomi, A. A., Olugbenga-Bello, A. I., Bamidele, J. O., Abodunrin, O. L., & Sabageh, O. A. (2014). Respiratory symptoms and peak expiratory flow among sawmill workers in South Western Nigeria. Journal of Environmental and Occupational Health, 3(3), 141–146. https://doi.org/10.5455/jeos.20140205093223

 Akinbami, L. J., Simon, A. E., & Rossen, L. M. (2019). Changing trends in pulmonary function among adults: Implications for respiratory health assessment. Chest, 155(3), 574–584.

 American Thoracic Society. (2019). Standardization of spirometry: 2019 update. An official American Thoracic Society and European Respiratory Society technical statement. American Journal of Respiratory and Critical Care Medicine, 200(8), e70–e88.

 Boschman, J. S., Frings-Dresen, M. H. W., & Sluiter, J. K. (2017). Exposure-response relationship between occupational wood dust exposure and lung function: A systematic review. Occupational and Environmental Medicine, 74(5), 315–321.  Eze, C. U., Aguwa, E. N., & Aniebue, P. N. (2021). Lung function among woodworkers in Nigeria. BMC Public Health, 21, 1234.

 Fawibe, A. E., Odeigah, L. O., & Sanya, E. O. (2017). Reference equations for peak expiratory flow rate in Nigerian adults. Annals of Ibadan Postgraduate Medicine, 15(1), 20–25.

 Forno, E., & Celedón, J. C. (2017). The effect of obesity on lung function. Journal of Allergy and Clinical Immunology, 139(4), 1071–1081.

 Global Initiative for Asthma. (2025). Global strategy for asthma management and prevention. https://ginasthma.org

 Ibhazehiebo, K., & Iyawe, V. (2019). Respiratory health of sawmill workers in Nigeria. Nigerian Journal of Clinical Practice, 22(5), 678–684.  International Labour Organization. (2024). Safety and health in forestry and wood-processing industries. Geneva, Switzerland: Author.

 Meo, S. A. (2019). Gender differences in lung function: Implications for respiratory health assessment. International Journal of Environmental Research and Public Health, 16(3), 1–10.

 Olatoke, F. (2020). Occupational exposure and lung function decline among industrial workers. Pan African Medical Journal, 35, 45.

 Pellegrino, R., Viegi, G., & Brusasco, V. (2005). Interpretative strategies for lung function tests. European Respiratory Journal, 26(5), 948–968.

 Peters, U., Suratt, B. T., Bates, J. H. T., & Dixon, A. E. (2018). Beyond BMI: Obesity and lung function. Thorax, 73(2), 190–195.  Quanjer, P. H., Stanojevic, S., & Cole, T. J. (2019). Multi-ethnic reference values for spirometry. European Respiratory Journal, 54(3), 1802143.

 World Health Organization. (2024). Protecting workers' health. Geneva, Switzerland: Author.