A cross-sectional study with an improved methodology to assess occupational air pollution exposure and respiratory health in motorcycle taxi driving.

Introduction: Motorcycle taxi driving is common in many African cities. This study tested whether this occupation is associated with more respiratory disorders in a context of widespread urban air pollution with an improved methodology.

Methods: In a cross sectional study we compared 85 male motorcycle taxi drivers in the capital city of the Republic of Benin (Cotonou) with an age and neighborhood matched control group. All participants carried a portable carbon monoxide data logger for 8 hours per day to assess exposure to air pollution. Respiratory symptoms were obtained using a standardized questionnaire and pulmonary function was assessed by spirometry.

Results: The two groups did not differ significantly (p>0.10) in their age, height, educational level, and exposures to smoke from biomass fuels and tobacco products. The taxi drivers were exposed to higher mean (SD) levels of carbon monoxide (7.6±4.9ppmvs. 5.4±3.8ppm p=0.001). They reported more phlegm and tended to have slightly lower levels of lung function, although these differences were not statistically significant.

Conclusion: In this cross sectional study of young motorcycle taxi drivers with substantial exposure to urban traffic and a matched control group, we found no evidence for respiratory impairment. A follow-up of such study population with other pollution exposure surrogate and other clinical endpoint may provide a more robust conclusion regarding the exposure response in this professional group.