Zemachu Ashuro ^1,2* Berhanu G. Debela ² Chala Daba ³ Habtamu Endashaw Hareru ² Samson W. Abaya ⁴ Anthony Byrne ⁵

• ¹ Dilla University, Dilla, Ethiopia
• ² School of public health, College of Health Science and Medicine, Dilla University, Dilla, Ethiopia
• ³ Department of Environmental Health, College of Medicine and Health Sciences, Wollo University, Dessie, Ethiopia
• ⁴ Department of Preventive Medicine, School of Public Health, College of Health Science, Addis Ababa University, Addis Ababa, Ethiopia
• ⁵ St Vincent’s Health Network Sydney (SVHNS), Sydney, Australia

Introduction: Inadequate ventilation and use of personal protective equipment is often observed in many occupational settings with high risk of dust and other fine particle exposure. Employees exposed to dust in their work environment may experience respiratory health problems. Previous systematic reviews on organic dust exposure and its association with respiratory health outcomes have not assessed. The objective of this systematic review and meta-analysis was therefore to summarize the reported effects of organic dust exposure on lung function parameters among industry employees in Africa.Methods: A compressive literature search was carried out in PubMed, MEDLINE, Google Scholar, EMBASE, the Web of Science, African Journals Online, and Science Direct to identify relevant studies for the review. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the included studies. The lung function indices: Forced Vital Capacity (FVC), Forced Expiratory Volume in the First Second (FEV1), the FEV1/FVC ratio, and Peak expiratory flow rate (PEFR) outcomes were extracted from primary studies and analyzed using STATA version 17. The I 2 -test was used to check the heterogeneity of studies. We used a random effects model to estimate pooled standard mean difference of lung function indices between organic dust exposed and non-exposed industry workers. To analyze the publication bias, funnel plots as well as Egger's test were applied.In this systematic review and meta-analysis, 32 studies with a total of 7,085 participants were included from 13,529 identified studies. The estimated mean differences with 95% confidence intervals FVC were -0.53 [-0.83 to -0.36] L, -0.60 [-0.77 to -0.43] L for FEV1, -0.43 [-0.57, -0.29] L for FEV1/FVC, and -0.69 [-0.88 to -0.50] L/min for PEFR.This systematic review and meta-analysis revealed that lung function indices: FVC, FEV1, FEV1/FVC, and PEFR were statistically significantly lower among organic dust exposed industry workers compared to non-exposed industry workers. Therefore, effective dust control measures should be implemented to prevent employees' exposure to organic dust.