A Study of Determination of Exhaled Carbon Monoxide and Carboxyhemoglobin in School Children

Background: carbon monoxide (CO) may play a role in pathophysiology of airway diseases. School children are at risk of exposure to environmental smoke. Adequate data regarding are not available. The measurement of exhaled CO level may provide an immediate, non-invasive method of fractional concentrations of CO in expired air. Exhaled CO levels & Carboxyhaemoglobin (COHb) reflects the exposure to environmental smoke. Aim: Hence, this study was done to investigate whether school children are exposed to environmental pollution by measuring the exhaled COHb and CO levels. Method: 654 school children of North Chennai with 329 clinically normal girls and 329 boys of age group 13 to 18 were included in the study. A single measure of CO was obtained with a CO CHECKPLUS machine. Exhaled CO levels in ppm and equivalent COHb in % are recorded at the same time. Results: The mean exhaled CO concentration and mean carboxyhaemoglobin (COHb) are not significantly changed in school children. The boys showed a significant (p<0.01) elevated mean exhaled CO concentration and mean carboxyhaemoglobin (COHb) levels than girls. Conclusion: The increased exhaled CO level in school boys than girls may be due to social and behavioral reasons.