[Exposure to environmental tobacco smoke and salivary cotinine concentration in a sample of students from Barcelona, Spain].

BACKGROUND AND

OBJECTIVE

The objective of this study was to assess the exposure to environmental tobacco smoke (ETS) by means of the concentration of salivary cotinine in a sample of adolescent students, and its relationship with active and passive tobacco consumption.

METHODS

A cross-sectional survey was conducted in 92 secondary education and high school pupils (16-20 years). Salivary samples were collected and salivary cotinine was measured by gas chromatography/mass spectrometry. Salivary cotinine medians and interquartile ranges were calculated. Significant statistical differences were detected with the non parametric test for medians.

RESULTS

The median of salivary cotinine concentration in current smokers was 91.5 ng/ml (RI: 62.4-125); in former smokers 7.9 ng/ml (RI: 5.1-15.5) and in never smokers 1.9 ng/ml (RI: 0-3.6). In smokers of more than 10 cigarettes per day, the result was 98.3 ng/ml (RI:63.4-142.9). Among non-smokers (never-smoker and ex-smokers), the median of salivary cotinine in non-smokers living with smokers was 3.3 ng/ml (RI: 0-8.6) versus 2.9 ng/ml (RI: 1.1-6.9) in those living with non-smokers.

CONCLUSIONS

The salivary cotinine concentration increases with the intensity of tobacco consumption and the perception of passive exposure to tobacco smoke.