Background: Ethiopia's sugar plants are growing to help the country's economy prosper. However, there is inconclusive evidence on the level of bagasse dust exposure and its respiratory health impacts among workers in sugar plants. This study assessed the degree of bagasse dust exposure and its effect on the respiratory health of the workers.

Methods: A longitudinal study was conducted among randomly selected samples of 1,043 participants in the sugar factories in Ethiopia. We measured the dust intensity using a calibrated hand-held real-time dust monitor once a month for five months, totaling 50 dust samples. Chronic respiratory symptoms were assessed using the American Thoracic Society respiratory symptoms questionnaire. Statistical analyses were done by SPSS version 26 software.

Results: In the boiler and power turbine sections, the geometric means of the dust concentrations were 9.55 and 7.89 mg/m3, respectively. This represented an exposure level to bagasse dust of 85.52% (95 % CI: 83.2 % -87.6 %). The extent of chronic respiratory symptoms was 60.6%, with wheezing (96.8%), cough (89.7%), and breathlessness (80.9%). Lack of dust control technology (β= 0.64, 95% CI; 0.53–0.75), and not practicing of wet spray (β = 0.27, 95% CI; 0.21–0.41) were factors associated with dust exposure. Chronic respiratory symptoms were associated with not wearing respiratory protection devices (β = 0.12, 95% CI; 0.30–0.56) and being exposed to bagasse (β = 0.56, 95% CI; 0.14–0.98).

Conclusions: Occupational dust exposure and respiratory health abnormalities were worrying concerns for sugar factory workers. The absence of dust control technologies and the practice of wet spray increased the level of exposure. Also, being exposed to bagasse dust and not wearing the correct respiratory protection gear increased the odds of having respiratory abnormalities. Thus, the use of mechanical solutions to stop dust emissions at their sources and the wearing of respiratory protection gear is highly advised.