Respiratory symptoms, lung function and dust exposure among workers in grain milling industries in Dar Es Salaam, Tanzania

Abstract

Background: Workers in grain milling industries are exposed to grain dust released during milling processes. Exposure to grain dust is associated to various respiratory symptoms such as phlegm, breathlessness, and cough and wheezing and it also leads reduced lung function. This study aimed at determining grain dust exposure levels and the prevalence of respiratory symptoms and Lung function among grain mill workers Dar es Salaam. Methodology: A descriptive cross sectional study was used to collect information on Respiratory symptoms among 264 grain mill workers and 100 controls by using a Questionnaire. Lung function tests were carried out on 180 grain mill workers and 68 controls by using an easy one spirometer while Personal dust exposure was measured on 30 grain mill workers and 5 controls by using PVC filters of 8µm pore size on two piece filter cassette mounted on Sidekick Casella (SKC) pump. P value of less than 0.05 was used as criteria for significant association. Ethical clearance was approved by the ethical clearance board of Muhimbili University of Health and Allied Sciences research and publication Committee. Results: Grain workers were exposed to higher levels of total dust with GM 12.15mg/m3 (GSD 1.53) than the control GM mg/m3 (GSD). Most of the workers in grain milling industries 66.7% were exposed to dust concentrations above the OEL (10mg/m3). The Prevalence of respiratory symptoms was higher among grain mill workers, (51.1%, 41.3%, 33.7%, 17%and 9.8% for cough, phlegm, breathlessness, tightness and wheezing respectively than in controls (28%, 19%, 21%, 8% and 5% for cough, phlegm, breathlessness, tightness and wheezing respectively. 26% and 21% of Grain workers were exposed to higher levels of total dust with GM 12.15 mg/m3(GSD 1.53) than control GM 0.17 mg/m3 (GSD 0.35). Conclusion: Exposure to grain dust in a working environment causes the increase in work related respiratory symptoms and reduced lung function. This study recommends the use of control measures to decrease dust exposure level among mill workers, also periodic medical examination should be conducted to assess workers health. A cohort study nationwide might give yield a more generalized outcome.