Smoke-Free Laws Benefit Kids, Too

June 7, 2010 -- Kids benefit from laws that regulate locations where smoking is allowed, a new study shows.

Smoke-free-air laws have already been shown to reduce exposure to secondhand smoke among adults. Now a study shows that such laws benefit children and adolescents, too, as long as they don't live with a smoker.

Researchers analyzed data from the 1999-2006 National Health and Nutrition Examination Survey and found that youngsters who live in a county with extensive smoke-free-air laws had a 39% lower prevalence of cotinine in their blood.

Cotinine, an alkaloid found in tobacco, is a major metabolite of nicotine and a common biomarker of secondhand smoke exposure. It is detectable in blood for a minimum of several days after exposure to tobacco smoke.

Researchers measured cotinine levels for 11,486 nonsmoking young people from 117 survey locations. Each location was categorized into one of three groups, indicating extensive, limited, and no coverage by a smoke-free law.

Among youngsters not exposed to secondhand smoke at home, those living in a county with extensive coverage of smoke-free-air regulations had a 39% lower prevalence of detectable cotinine in their blood compared with youth without a smoke-free air law.

The research suggests that smoke-free laws work and benefit kids except those who are exposed to secondhand smoke at home.

Researchers say 69.7% of the nonsmoking youths in the study lived in counties without smoke-free laws, 8.6% lived in counties with limited coverage, and 21.7% in counties with extensive coverage.

More than half, or 56.4%, of all nonsmoking youths had some cotinine levels in their blood.

The researchers also report that:

• Young people from areas with extensive coverage of a smoke-free law had a lower percentage with detectable cotinine (32.7%), compared with kids from a county with limited coverage (49.6%) or no coverage (64.6%).
• About 21% reported exposure to secondhand smoke at home; 98% of this group had detectable levels of cotinine.
• 45.4% of kids in homes with no smokers had detectable traces of cotinine.

"The findings suggest that smoke-free laws are an effective strategy to protect both children and adults from exposure to secondhand smoke. In addition, interventions designed to reduce or prevent adults from smoking around children are needed," says study researcher Melanie Dove, PhD, MPH, of the Harvard School of Public Health.

The researchers conclude that smoke-free laws should continue to be enacted, and say more steps are needed to convince adult smokers to quit, since about 20% of youths in the study lived with a smoker in the home. Smoking parents may need counseling from doctors to quit, the researchers say.