[Exposure to cassava, corn and soybean dust and respiratory health among artisanal millers in Lubumbashi (Democratic Republic of the Congo)].

Abstract

Objectives: The aim of this study was to determine the prevalence of respiratory symptoms, their determinants, and the state of respiratory function in millers exposed to cassava, maize, and soybean dust in Lubumbashi, Democratic Republic of Congo (DRC), compared with a group of unexposed workers.

Methods: A descriptive and analytical cross-sectional study was conducted in 2015 on 288 millers and 118 agents (n = 406) from a security agency (control group) in Lubumbashi, DRC. Participants were examined at their place of work. Respiratory health information was collected using a standardized questionnaire. Spirometry was performed on each participant.

Results: Mean age was 27.6 ± 9 years in millers and 28.5 ± 7 years in controls. Daily working hours were 12.1±1.7 hours for millers and 14.4±6.2 hours for controls. No significant differences were found when comparing the two groups. However, the prevalence of respiratory symptoms was higher in the millers than in the controls, especially wheezing (1.9 times higher), dyspnea (2.1 times higher), breathlessness at rest (6 times higher), breathlessness on exertion (6.4 times higher), chronic bronchitis (6.2 times higher), cough (5.3 times higher) and morning sputum (5.1 times higher). Thus, an association was found between the milling occupation and all respiratory symptoms. Spirometric data showed that forced expiratory volume in one second (FEV1), peak expiratory flow (PEF) (p<0.05) and Tiffeneau ratio (FEV1/FVC) (p<0.001) were significantly reduced in millers compared to controls.

Conclusions: This study showed a high prevalence of respiratory symptoms with impaired lung function among millers in Lubumbashi, suggesting the need for preventive measures to reduce exposure in mills.