Saliva Cotinine as an Indicator of Cigarette Smoking in Adolescents

Abstract

Summary Saliva cotinine and expired‐air carbon monoxide (CO) concentrations were measured in 508 girls aged 11–16 years attending an inner London comprehensive school. A saliva cotinine cut‐point of 14.7 ng/ml detected 99% of regular daily smokers and performed better than expired‐air CO (cut‐point 7 ppm) in identifying smoking (69% versus 54%). The mean saliva cotinine among the regular daily smokers was 200.8 ng/ml, and comparisons with adult smokers suggested that these adolescents were inhaling a similar dose of nicotine per cigarette. Within our sample no evidence was found for an increase in smoke inhalation per cigarette with increasing age suggesting that inhalation develops early in the smoking career.