Children living in communities that ban smoking in indoor public places are 39 percent less likely to have chemical biomarkers indicating exposure to tobacco smoke, according to researchers at the Harvard School of Public Health.
Researchers led by Melanie Dove analyzed the levels of cotinine — a nicotine metabolite — in the blood of 11,486 nonsmoking youth ages 3-19, comparing children living in counties with smokefree laws to those who lived in counties that lacked such laws.
Children living in nonsmoking homes had 43-percent lower mean cotinine levels, the study found. Researchers said that the home is the most common source for youth secondhand-smoke exposure; 20 percent of kids in the study lived with a smoker.
The study is published online in the journal Pediatrics.