Factors Associated with Secondhand Smoke Exposure in Infants


1 Department of Reproductive Health, Tehran University of Medical Sciences

2 Department of Toxicology

3 Department of Statistic

4 Department of Clinical Biochemistry, Tarbiat Modares University

5 Tobacco Prevention and Control Research Center, Shahid Beheshti University M.C.

6 Iranian Ministry of Health and Medical Education, TEHRAN-IRAN.


Background: Determining the factors associated with secondhand smoke (SHS) exposure in children provides valuable information for smoking control strategies. This study aimed to assess factors related to SHS exposure in infants based on urinary cotinine measures. Materials and Methods: A cross-sectional analysis of the data that were collected as part of the randomized controlled trial was conducted. Participants were 130 smoking households with children under the age of 1 year attending a health care center in southern Tehran. Eligible parents consented to participate in this study and completed a questionnaire including demographic data, questions regarding smoking at home, smoking status and Fagerström test through face-to-face interview. The Infants’ urinary cotinine level was measured using gas chromatography, adjusted with urinary creatinine level and reported as cotinine (ng)/ creatinine (mg). Factors related to infants’ SHS exposure were assessed using the multivariate logistic regression model based on standard cut-point (30 ng of urinary cotinine/mg creatinine). Results: The final multivariate logistic regression model showed that social status (p=0.002), home smoking restriction (p=0.05) and the infant's age (p=0.01) were associated with the infants’ SHS exposure determined based on urinary cotinine levels. Conclusion: These results support the influence of social status, home smoking restriction and infant's age on the exposure of infants to SHS. (Tanaffos2010; 9(2): 43-49)