Carboxyhaemoglobin Levels among Traders Exposed to Vehicular Emissions in Three Motor Parks in Ibadan, Nigeria

Abstract EN

Carbon monoxide (CO) remains a leading cause of work-related chemical poisoning.

Vehicular emissions are the primary daily ambient source of CO in urban Nigerian motor parks, where there have been few human exposure studies.

Using a cross-sectional comparative design, we assessed carboxyhaemoglobin levels (% COHb), a biomarker of CO exposure, among traders at three motor parks (AMP, IMP, and NMP) and other traders (nonmotor park workers) in Ibadan, Nigeria, using a noninvasive pulse CO-dosimeter (Rad 57).

Ninety-three traders were proportionally allocated between motor parks; 93 other traders were selected based on specific study inclusion criteria.

Mean ages of motor park traders and other traders were comparable, 37.8±11.1 and 38.7±9.6, respectively.

Mean % COHb for traders (range 3–22) at AMP, IMP, and NMP was 11.2±3.8, 11.6±3.1, and 12.2±3.3, respectively, while mean % COHb for other traders was about three times lower, 4.1±1.7 (range 2–8).

Overall, mean % COHb for motor park traders, 11.7±3.3, was also significantly higher than for other traders (p<0.05).

Nevertheless, mean % COHb for both groups exceeded the current World Health Organization guideline, 2.5%.

This study suggested that motor park traders have higher % COHb and thus are highly susceptible to exposure and more vulnerable to known risks of adverse health effects from exposure to CO.