Chronic respiratory symptoms, lung function and associated factors among flour mill factory workers in Hawassa city, southern Ethiopia: "comparative cross-sectional study"

Abstract

Background: Occupational related respiratory diseases arise as a result of the deposition of dust particles in the lungs. Flour milling industries; generate organic dust during industrial processes, such as cleaning, milling, packaging, and loading which release dust into the air and later inhaled by workers. Flour mill workers are at risk of developing respiratory health problems because of exposure in their working environment, but existing data were few. The aim of this study was to assess the prevalence of chronic respiratory symptoms, lung function and associated factors among flour mill factory workers. Methods: A comparative cross-sectional study was conducted among 196 flour mill factory workers and 210 soft drinks factory workers. We selected study participants using a systematic sampling technique. We assessed the chronic respiratory symptoms using the questionnaire adopted from the British Medical Research Council. Binary logistic regression analysis with 95% CI and p < 0.05 was used to identify the factors. Lung function parameters; Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1) and ratio FEV1/FVC was measured by using spirometer and analyzed by using an independent t-test. Results: We included 406 (96.7%) workers in this study. The prevalence of chronic respiratory symptoms was higher among flour mill workers as compared to soft-drinks factory workers (56.6% vs.12.9%). Primary education (AOR = 5.8, 95% CI, 1.3-23.2), mixing department (AOR = 5.3, 95% CI = 1.68-16.56), work experience 6-9 years (AOR = 5.1, 95% CI = 2.05-12.48), work experience ≥10 years (AOR = 2.5, 95% CI = 1.01-6.11) and working over eight hours (AOR = 2.4, 95% CI, 1.16-5.10) were factors that significantly associated with chronic respiratory symptoms among flour mill workers. FVC (p < 0.002), FEV1 (p < 0.001) and FEV1/FVC (p < 0.012) were significantly reduced among flour mill workers. Conclusions: We found chronic respiratory symptoms to be high among flour mill workers. Lower education level, mixing department, increased work experience, and longer working hours were identified factors. The flour mill dust exposed worker's lung function parameters were highly reduced. This study suggested that workers' dust exposure reduction and control methods in flour mill factories need to be implemented.