Respiratory symptoms, lung function and contributing factors among iron foundry workers in Dar es Salaam, Tanzania.

Abstract

Background: Common activities in foundry such as welding, heating, cutting, molding etc expose workers to dusts, gases and fumes which as a result lead to respiratory symptoms like wheeze and dyspnea on acute. Prevalence of respiratory symptoms have been studied in different areas like in coffee, sisal, coal and spray painting none has been done on iron foundry industry in Tanzania. This study focused on respiratory symptoms, lung function and contributing factors among iron foundry workers in Dar es Salaam. Method: Analytical cross-sectional study was conducted. A purposive non random proportionate to sample size was used to obtain 300 iron foundry workers from three iron foundries, who were interviewed, measured peak flow rates and dust sampling. Results: Proportion of respiratory symptoms highly reported were Wheezing 39% (n=117) and Cough 32.3% (n=97), SoB 21.7 %( 65) and phlegm25.3 % (76). Workers who did not get on job training have shown high odds of getting shortness of breath 1.265(0.548-2.917. After adjusting for age iron foundry workers who did not get job training showed odds of 1.188(0.588-2.400) of developing wheeze symptom. Workers who did not get on job training showed odds of 1.112 (0.521-2.372) of developing phlegm. Iron foundry workers with no on job training showed odds of 1.320 (0.647-2.691) of developing cough symptom. The mean peak expiratory flow rates for iron foundry workers was 440.55 ± 107.66 less than predicted mean peak flow rates 606.12 ± 42.27. Dust measument in Industry A= 1.1041mg/m3, industry B= 2.2894mg/m3 and industry C= 0.5398mg/m3. Dust measurements among job categories were Furnace 2.1858mg/m3, raw mill was 0.530mg/m3 and Loading was 0.573mg/m3. Dust measument results could not show statistical significant association with the respiratory symptoms. Conclusion and recommendations: Prevalence of respiratory symptoms highly reported were wheeze and cough, there was significant decreased in lung functioning due to decreased in peak expiratory flow rates. Observed contributing factors were lack of on job training, cigarettes smoking and long working experience, poor use of dust filters, and job tasks. Recommended cigarette smoking cessation, job trainings, job rotation and work shifts, use of protective gears, and further cohort studies in iron foundry.