Dad's in-home smoking may harm family's health

Fathers-to-be who smoke and want to protect the health of their families should take it outside, suggests new research from Korea.

Newborns whose fathers had smoked in the home had higher levels of nicotine in their hair than babies born to non-smoking dads, Dr. Moon-Woo Seong of the National Center in Goyang and colleagues found. But infants whose fathers smoked, but only did so outdoors, had no more nicotine in their hair than babies whose fathers did not smoke at all.

"Outside smoking substantially reduces maternal and fetal exposure," they conclude.

The study, reported in the latest issue of the American Journal of Epidemiology, included 63 mother-father-newborn trios. None of the mothers in the study were smokers, or were regularly exposed to second-hand smoke outside the home. In 27 families neither parent smoked, fathers only smoked outdoors in 27 of the families, and in 9 families the father smoked indoors.

Mothers living with smokers had significantly more nicotine and its byproduct cotinine in their hair, Seong and colleagues found, but there were no significant difference between nicotine and cotinine levels in the hair of babies with non-smoking fathers and those with smoking fathers.

However, when the researchers looked separately at indoor and outdoor smoking, they did find higher nicotine levels in the children of indoor smokers compared to outdoor smokers.

Based on average nicotine levels, note the researchers, the wife of an indoor smoker is exposed to 7.4 percent of all of the smoke her husband consumes, while 16.7 percent of the smoke a mother inhales is passed to her fetus.

"Our findings," the team concludes, "indicate that paternal smoking inside the home leads to significant fetal and maternal exposure to environmental tobacco smoke. We also found that paternal smoking outside the home helpfully reduces levels of environmental tobacco smoke to which the smoker's wife and her fetus are exposed."