Smoking, passive smoking and urinary cotinine level in an older Chinese cohort: The Guangzhou biobank cohort study

Abstract

Objective: To measure the smoking status in an older Chinese cohort and their urinary cotinine levels.

Methods: 7349 women and 3064 men aged 50-89 years were recruited in the first phase of the Guangzhou Biobank Cohort Study during 2003~2004. Information on smoking history, second hand smoke exposure, other lifestyles and socioeconomic factors was collected by standardized interview. Urinary continine levels were measured by HP-SMS fused-silica capillary column separation and GC-MS identification.

Results: (1) The mean (± SD) age in men and women was 64.0±6.0 and 66.2±5.8 years respectively. (2) 10% were farmers , 46% factory workers, and 44% technicians, managers and others. (3) About one half had no formal schooling or had primary education. Only 9% had college education or above. (4) In women, 7.3% (269/7349) were current smokers, 4.1% (301/7349) ex-smokers, 49.7% (3652/7349) never smokers; and of the never smokers, 42.6% (3127/7349) were exposed to second hand smoke in the workplace or at home . In men, 30.5% (932/3064) were current smokers, 36.8% (1124/3064) ex-smokers, 28.8% (882/3064) never smokers; and of the never smokers, 4.1% (126/3064) were exposed to second hand smoke in the workplace. (5) urinary cotinine levels in men were: never smokers (NS) 5.74±11.66, passive smokers (PS) 5.99±11.82, occasional smokers (OS) 17.40±40.74, ex-smokers (ES) 20.74±43.54, and current smokers (CS) 73.52±72.24 ug/L. The corresponding figures in women were: NS, 1.31±6.67; PS, 1.38±5.48; OS, 3.45±9.91; ES, 9.91±24.99 and CS, 23.22±28.56 ug/L.