Exposure to occupational dust and changes in pulmonary function among cobblestone paving workers of Jimma, Ethiopia

Abstract

The classic diseases of "dusty" occupations may be on decline, but they are not yet extinct. Studies have found associations between changes in ambient particulate air pollution and increased cardiorespiratory morbidity and mortality. A cross-sectional comparative study design was employed on 127 male nonsmoker cobblestone paving workers and 194 matched employed office workers as a reference in order to assess changes in pulmonary function related to dust exposure among cobblestone road paving workers of Jimma zone, Ethiopia. Data was collected using structured questionnaires and spirometric measurements after ethical clearance was obtained. Data was analyzed using unpaired t-tests to examine the differences between the groups. P-values equal or less than 0.05 were considered statistically significant; odds were calculated at a 95% confidence interval. Cobblestone road paving workers had significantly higher odds of respiratory symptoms, dry cough (p < 0.05), cough (p < 0.01) and sore throat (p< 0.001) compared to the reference. The FEV1 for workers exposed to cobblestone road paving workers ranged between 3.12 - 4.73 L, with a mean of 3.96 ± 0.6 L, significantly lower than the reference groups who had a range of 3.3 - 4.78 L and a mean of 4.01 ± 0.6 L (p < 0.05). The mean value of the ratio of FEV1/FVC was significantly decreased in the cobblestone road paving workers compared to the controls (87.2 (SD 4.3) v 89.5 (SD 5.4), p = 0.01). In conclusion, the study revealed clear evidence of the need for health education and for the promotion of activities directed towards mitigating respiratory hazards in order to foster a safe and healthy work environment.