Traffic-Related Carbon Monoxide Exposure, Carboxyhaemoglobin Levels,and Arterial Stiffness among Public Transport Workers in Dakar, Senegal:A Cross-Sectional Study

Introduction: Air pollution is a major public health concern, particularly in rapidly urbanizing African cities where vehicular traffic dominates. Road transport workers are at risk of chronic carbon monoxide (CO) exposure, but data on its health effects are limited. This study assessed CO exposure, carboxyhemoglobin (HbCO) levels, and their association with subclinical symptoms and arterial stiffness among public transport workers in Dakar, Senegal. Methods: A cross-sectional study enrolled 76 publics transports workers. Sociodemographic, occupational, and smoking data were collected via questionnaire. Exhaled CO and HbCO levels were measured, and pulse wave velocity (PWV) was assessed. Logistic and linear regression analyses evaluated associations between HbCO and respiratory symptoms or PWV, adjusting for age, BMI, smoking, and employment duration. Results: Participants were predominantly male, mean age 35.2 ± 8.3 years, BMI 24.8 ± 3.1 kg/m², working 16 ± 1.5 hours/day and 6.2 ± 0.8 days/week; 11.8% were current smokers. Mean exhaled CO was 3.72 ± 3.21 ppm, and mean HbCO was 1.26 ± 0.53%, with 26% exceeding 1.5%. HbCO strongly correlated with exhaled CO (r = 0.68, p < 0.001). Neurological (headache 23.7%) and musculoskeletal (back pain 21.1%) complaints were common. Respiratory symptoms occurred in 19.7% of participants, with higher prevalence in those with HbCO >1.5% (27% vs 8%, p = 0.003). PWV averaged 12.03 ± 14.0 m/s; participants with HbCO >1.5% had significantly higher PWV, and linear regression showed a positive association between HbCO and PWV (β = 0.29, 95% CI 0.02–0.56, p = 0.034). Conclusion: Public transport workers in Dakar experience chronic CO exposure. Elevated HbCO was associated with increased respiratory symptoms and arterial stiffness, suggesting early subclinical cardiovascular and respiratory effects. These findings highlight the need for occupational health interventions and further research on air pollution impacts in sub-Saharan Africa.