Normal values of carboxyhemoglobinemia and methemoglobinemia in a sample of conscripts

Carboxyhemoglobin (COHb) and methemoglobin (MetHb) values in blood were measured in a population of 296 asymptomatic conscripts who were not under medical treatment and had no occupational exposure. The mean COHb value was 3.25 (S.D. = 1.45%) in smokers and 1.34 (S.D. = 0.8) in non-smokers, with a wide variability in both subgroups, particularly among smokers. The COHb levels in moderate smokers were lower than in heavy smokers, but smoking just before the blood test greatly increased the COHb levels. Non-smoking country dwellers had lower COHb levels than non-smoking city dwellers, but the COHb levels of smokers were independent of residence and were only smoking-related. The sample MetHb level was 0.81 (S.D. = 0.37) and was influenced by country living and smoking. Levels were lowest in non-smoking country dwellers (0.66, S.D. = 0.38%) and increased with moderate smoking (0.71, S.D. = 0.40%). Heavy smoker levels were independent of residence. Smoking just before the blood test had no effect on the value.