Restrictions on smoking at home and urinary cotinine levels: First report

Introduction: Exposure to secondhand smoke causes many diseases among children. There are more than 700 million secondhand smokers aged less than 5 in the world. Homes and cars seem to be the main places where children are exposed to secondhand smoke. The purpose of this study was to assess the extent of exposure to environmental tobacco smoke in infants by using cotinine biomarker.
 Methods:The data used in this study were part of a randomized controlled trial of a smoking change intervention for parents of infants attending a health center affiliated with Tehran University of Medical Sciences in Tehran in 2008. A total of 130 smoking households with children before the age of 1 year consented to participate in this study. Data was collected from parent of children through face-to-face interview. Cotinine levels of urine samples from children measured smoke exposure to confirm reports of home smoking status.

 Results:The mean age of infants was 4.2 months and 60.0% were boys. Overall, 40.8% of parents reported ban on smoking in the home to some extent; but only 12.3% smoking ban in their home with no exceptions; 17.7%, smoking was limited to one part of the home; and 26.9%, unrestricted smoking was allowed in common rooms of the home. Of the 53 respondents who had a car; only 5.7% reported that smoking was restricted completely in the car. Children living in homes with complete smoking restrictions had less exposure to secondhand smoke, as measured by urinary cotinine to creatinine ratios.

Conclusion:Many children remain exposed to secondhand smoke in the home and car. Preliminary analysis indicates a need to increase efforts to encourage the adoption of smoke-free home and car rules for children who have parents who smoke.