Abstract:
Background: Chronic respiratory symptoms—including chronic cough, chronic phlegm,
wheezing, shortness of breath, and chest pain—are common outcomes of occupational exposure
to particulate matter with diameters of 10 μg/m³ (PM₁₀) and 2.5 μg/m³ (PM₂.₅). However, localized
data are scarce, limiting the development of targeted occupational health interventions and leaving
workers at continued risk.
Objective: To assess the level of particulate matter (PM₂.₅ and PM₁₀) and its association with
chronic respiratory symptoms among cement factory workers in Dire Dawa City, Eastern Ethiopia
from February 1 to March 15, 2025.
Methods: An institution-based cross-sectional study was conducted among cement factory
workers in Dire Dawa. Out of a total of 938 workers in the study area, 300 participants were
randomly selected. Because dust exposure varied across different working units, workers were
stratified by department, and samples were proportionally allocated to each stratum. Data were
collected through face-to-face interviews using structured questionnaires.The data were analyzed
using SPSS version 25.0. Binary logistic regression was used to identify candidate variables (p <
0.25 at 95% CI) for inclusion in the multivariable analysis. Subsequently, multivariable logistic
regression was performed to identify factors associated with occupational chronic respiratory
symptoms among cement factory workers. A p-value < 0.05 was considered statistically
significant.
Results: A total of 300 factory workers were approached for the study, achieving an overall
response rate of 97%. Out of this, 179 (61.5%) [95% CI: 55.7-67.1] were experienced one or more
chronic respiratory symptoms in the last 12 months. The emission levels of PM₂.₅ and PM₁₀ varied
across working units in the cement factory, ranging from the lowest in the administrative unit (21.5
and 25.2 μg/m³, respectively) to the highest in the raw material receiving unit (4722 and 4998
μg/m³, respectively), exceeding both national (65 and 150 µg/m3) and WHO (15 and 45 µg/m3) air
quality standards, respectively. Chronic respiratory symptoms were significantly associated with
working in the raw material receiving unit [AOR: 3.2; 95% CI: 1.27–7.80], cement milling unit
[AOR: 4.06; 95% CI: 1.49–11.10], and packing unit; working more than 48 hours per week [AOR:
2.11; 95% CI: 1.03–4.31]; not using PPE [AOR: 2.31; 95% CI: 1.28–4.16]; and cigarette smoking
[AOR: 2.30; 95% CI: 1.14–4.64].
Conclusion: The study indicates a high prevalence of chronic respiratory symptoms among
cement factory workers, with PM₂.₅ and PM₁₀ levels significantly exceeding national and WHO
air quality guidelines, highlighting an urgent need for improved occupational health interventions.
