BACKGROUND: The measurement of carbon monoxide concentration in expired air is used as an objective method to analyze the smoking status. This method has been proven to be reliable and is used throughout the world but it has been only recently accepted in Korea. Therefore the purpose of this study was to examine if measuring the concentration in expired air accurately reflects the Korean's smoking status. METHODS: The subjects were from ages of 19 through 75 healthy people including smokers and nonsmokers. The smokers had their carbon monoxide measured after answering a questionnaire. This questionnaire was formed to obtain information concerning smoking status, smoking habit and factors that influence carbon monoxide measurement. Micro II smokerlyzer (Bedfont Instruments Ltd., England) was used to analyze CO concentration in expired air. The method used for measuring CO concentration was to deeply inhale and hold one's breath for 15 seconds and measure CO concentration while exhaling. RESULTS: The total number of subjects was 148(143 males, 5 females) consisting of 114 smokers, 34 non smokers(never smokers 23, ex smokers 11). The average CO concentration in exhaled air in smokers was 17.247.30 ppm, in nonsmokers 6.031.06 ppm(in ex smokers 6.361.29 ppm, in never smokers 5.870.92 ppm). A significant difference was evident between smokers and non smokers(P<0.0001). The CO concentration values compared among the groups divided in terms of daily smoking rate were as the following 11.885.57 ppm in subjects smoking less than 10 cigarettes/day, 17.356.48 ppm in those smoking 11 20 cigarettes/day, 20.006.35 ppm in the 21 30 cigarettes/day group, and 24.889.70 ppm in the 31 cigarettes/day group (p<0.0001). In addition, the CO concentration was influenced by the change of the degree of inhalation and the elapsed time since last smoking. CONCLUSION: The measurement of CO concentration in exhaled air among the Koreans proved to be an accurate and reliable method reflecting the present smoking status.
Carbon Monoxide* ; Carbon* ; Exhalation ; Humans ; Inhalation ; Korea ; Male ; Smoke* ; Smoking* ; Surveys and Questionnaires

Sakai's method has been known as the simplest one for determination of erythrocyte pyrimidine 5'-nucleotidase (P5N) activity using high performance liquid chromatography(HPLC). However the drawback of the method is that it is difficult to wash the erythrocyte for isolation. To search for the simpler method, we compared Sakai's method with other methods using whole blood treated with heparin and concanavalin A or whole blood treated with EDTA-2K instead of washing the erythrocyte. The mean concentrations of lead in blood samples collected from 44 male and 16 female workers who are healthy without any exposure to lead in their workplace were 4.30 +/- 1.31 microgram /dl (mean +/-standard deviation), which were measured by frameless atomic absorption spectrophotometer. Erythrocyte P5N activities were measured by 3 methods; Sakai's method(Method I), using whole blood treated with heparin and concanavalin A (Method II), and using whole blood treated with EDTA-2K (Method III). The results were obtained as follows ; 1. The mean of erythrocyte P5N activity by Sakai's method(Method I) were 12.7 +/-2.47 amole uridine/hr/gm of Hb. 2. The mean of erythrocyte P5N activity by the method using heparinized whole blood treated with concanavalin A(Method II) were 13.1 +/-2.41 micromole uridine/hr/gm of Hb. 3. The difference of mean erythrocyte P5N activity between Method I and Method was not significant. 4. The erythrocyte P5N activity by the method using whole blood treated with EDTA-2K (Method III) was significantly different from Method I. We thought that omission of incubation period which was required on Method III using EDTA-2K caused the difference between Method I and Method III. 5. Simple linear regression equation for erythrocyte P5N activity between Method I (Y) and Method II(X) was significant: Y = -0.012 + 0.9724 X. These results suggest that the method using whole blood treated with heparin and concanavalin A is simpler to examine the erythrocyte P5N activity as a biological indicator of lead intoxication than Sakai's method.
5'-Nucleotidase* ; Absorption ; Concanavalin A ; Erythrocytes* ; Female ; Heparin ; Humans ; Linear Models ; Male

Sakai's method has been known as the simplest one for determination of erythrocyte pyrimidine 5'-nucleotidase (P5N) activity using high performance liquid chromatography(HPLC). However the drawback of the method is that it is difficult to wash the erythrocyte for isolation. To search for the simpler method, we compared Sakai's method with other methods using whole blood treated with heparin and concanavalin A or whole blood treated with EDTA-2K instead of washing the erythrocyte. The mean concentrations of lead in blood samples collected from 44 male and 16 female workers who are healthy without any exposure to lead in their workplace were 4.30 +/- 1.31 microgram /dl (mean +/-standard deviation), which were measured by frameless atomic absorption spectrophotometer. Erythrocyte P5N activities were measured by 3 methods; Sakai's method(Method I), using whole blood treated with heparin and concanavalin A (Method II), and using whole blood treated with EDTA-2K (Method III). The results were obtained as follows ; 1. The mean of erythrocyte P5N activity by Sakai's method(Method I) were 12.7 +/-2.47 amole uridine/hr/gm of Hb. 2. The mean of erythrocyte P5N activity by the method using heparinized whole blood treated with concanavalin A(Method II) were 13.1 +/-2.41 micromole uridine/hr/gm of Hb. 3. The difference of mean erythrocyte P5N activity between Method I and Method was not significant. 4. The erythrocyte P5N activity by the method using whole blood treated with EDTA-2K (Method III) was significantly different from Method I. We thought that omission of incubation period which was required on Method III using EDTA-2K caused the difference between Method I and Method III. 5. Simple linear regression equation for erythrocyte P5N activity between Method I (Y) and Method II(X) was significant: Y = -0.012 + 0.9724 X. These results suggest that the method using whole blood treated with heparin and concanavalin A is simpler to examine the erythrocyte P5N activity as a biological indicator of lead intoxication than Sakai's method.
5'-Nucleotidase* ; Absorption ; Concanavalin A ; Erythrocytes* ; Female ; Heparin ; Humans ; Linear Models ; Male