However, the study, published in Cancer Epidemiology, Biomarkers & Prevention, doesn't show if babies exposed to chronic secondhand-smoke exposure later have a higher cancer risk.
"The take-home message is, 'Don't smoke around your kids,'" researcher Stephen Hecht, Ph.D., says in a news release. Hecht is the Wallin Professor of Cancer Prevention at the University of Minnesota's Cancer Center.
Hecht and colleagues studied 144 Minneapolis babies. The babies were 3 to 12 months old and lived in homes with a mother (and possibly other people) who smoked.
The scientists took urine samples from the babies. They also interviewed the babies' mothers about smoking habits and the infants' exposure to secondhand smoke at home, in cars, or at other places.
The goal: Check the babies' urine samples for total NNAL, a biomarker of a tobacco-specific carcinogen (something that may cause cancer).
Tobacco Chemicals Detected
The urine samples of 67 babies (about 46 percent) showed detectable levels of total NNAL. Those babies came from households where 76 cigarettes per week were smoked, compared with 27 weekly cigarettes in households where total NNAL wasn't detected.
"With more sensitive analytical equipment, the NNAL from urine of babies in lower frequency cigarette smoking households would most likely be detectable," Hecht says in the news release.
The babies were not studied over time, so the researchers don't know how (or if) chronic secondhand-smoke exposure affected the kids' health later in life. Previous studies of secondhand smoke typically haven't focused on infants, note Hecht and colleagues.
The best solution is for all household members to quit smoking, ideally before pregnancy, and to have a no-smoking policy in the home and cars, the researchers note.
They add that nicotine has been found in dust and surfaces in smokers' households. For that reason, "the complete elimination of smoking in homes is preferable to an emphasis on not smoking in the presence of children," Hecht's team writes.
Sources:Hecht, S. Cancer Epidemiology Biomarkers & Prevention, May 2006; Vol. 15: pp. 988-992. News release, American Association for Cancer Research.
By Miranda Hitti
Reviewed by Louise Chang, M.D.
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