Objective To understand pulmonary ventilation function damage among excavation workers, and to identify impact of dust exposure duration on pulmonary function.
Methods A total of 221 excavation workers in a coal mine were selected as dust exposure group, and 83 workers without dust exposure in the same mine as controls. Unified physical examinations and pulmonary function tests were provided. All results were presented as relative values. Chi-square test and covariance analysis were used for statistical analysis.
Results Significant differences in abnormal lung function rates were found between subjests having smoking history in the exposure and the control groups (P < 0.05), but not found between those without smoking history. The rate of abnormality in excavation worker's pulmonary function was higher than that of the controls (P < 0.05). In covariance analysis, with smoking as the covariant, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1.0), peak expiratory flow rate (PEFR), FVC best, FEV1.0 best were significantly lower in the excavation workers than in the controls (P < 0.05); PEFR and the maximum flow rate at 25% of FVC devided by body height (V25/Ht) were significantly lower in the workers with ≥ 30 years of work duration than in those with ≥ 10 years and ≥ 20 years of work duration; the distributions of chronic obstructive pulmonary diseases were not significantly different between the exposure and the control groups, and same results were found between the exposure groups with different lengths of work duration.
Conclusion Excavation worker's lung function is significantly worse than controls'. The pulmonary ventilation functions reduce with extention of the length of dust exposure. Pulmonary function tests can be used to monitor lung damages in workers exposed to dust.
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