Background: Tricyclists are continuously exposed to vehicle emissions and other environmental pollutants, due to the na- ture of their job and vehicle design, which may be hazardous to health. However, there is paucity of data on the pulmonary functions of commercial tricyclists in Nigeria, which should have provided insight into any relevant health concerns in this population, hence this study. Objectives: This study evaluated the pulmonary functions of tricyclists, in comparison with those of age-matched non-tri- cyclists. Methods: Two hundred and ten (210) [150 commercial tricyclists; 60 non-tricyclists] males (aged 20-65years) participated in this unmatched case-control study in Enugu, Enugu state, Nigeria. Their pulmonary functions [Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), Peak Expiratory Flow Rate (PEFR)] were assessed using a computerized spirometer. Independent T-test and Pearson Chi-square were used to analyze data at a significant level of P<0.05. Results: Cough (46.0%) and dust allergies (40.7%) were the commonest reported respiratory symptoms among tricyclists. There were significant differences in the FVC (P<0.001), FEV1 (P<0.001) and PEFR (P<0.001) between the two groups, with tricyclists showing lower pulmonary function values. FEV1/FVC was <70% with increased FVC in 83.3% of the tricy- clists, suggesting restrictive pulmonary abnormalities. Conclusion: Decreased pulmonary function values of commercial tricyclists in this study is suggestive of their predisposi- tion to occupation-related pulmonary disorders, particularly the restrictive patterns. Keywords: Tricyclists; Keke Napep riders; pulmonary functionss; Nigeria.

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