Smoking, carboxyhaemoglobin, carbon monoxide in expired air and aryl hydrocarbon hydroxylase inducibility. A cross-sectional study and anti-smoking applications in middle-aged men.

In this cross-sectional study we report on the distributions of carboxyhaemoglobin in blood (COHb%), carbon monoxide in expired air (CO), and aryl hydrocarbon hydroxylase (AHH) inducibility in age-matched samples of males born 1934-36 and 1921, attending our ongoing preventive medical health screening program in Malmö. Both COHb% and CO showed great interindividual variations in the smokers; potentially of value as a complement to smoking history to identify smokers at high risk of tobacco-related diseases. They also provide powerful arguments for quitting smoking. Therefore, CO is now measured and discussed by the nurses as part of the screening investigation in all smokers. Neither COHb% nor CO showed correlations to the AHH induction levels. There were no associations between the latter and the smoking category, which supports that AHH inducibility is under genetic control. However, high AHH induction in smokers implies an increased risk of smoking-induced carcinogenesis. Smokers with high AHH inducibility identified in the screening have, therefore, been invited to antismoking information and counselling.