Search Here

Being exposed to secondhand smoke may make children more physically aggressive and antisocial, according to a new study.

Researchers said the link between aggressive behavior and secondhand smoke holds true, regardless of whether children were exposed to smoke during pregnancy or if their parents have a history of being antisocial.

Lead researcher Linda Pagani of the University of Montreal's School of Psychoeducation said that the findings are troublesome because 40 percent of children worldwide are exposed to secondhand smoke.

"Secondhand smoke is in fact more dangerous that inhaled smoke," Pagani said in a news release.

"Moreover, exposure to this smoke at early childhood is particularly dangerous, as the child's brain is still developing," she added.

The latest study published in the Journal of Epidemiology and Community Health on May 21 involved data from 2,055 kids from their birth until ten years of age.  Researchers examined parent reports about secondhand smoke exposure and reports from teachers and children themselves about classroom behavior.

The study found that kids exposed to secondhand smoke, even temporarily, were significantly more likely to report themselves as being more aggressive by the time they finish the fourth grade.

While the study cannot conclude that there is a direct causal link, researchers said the statistical correlation suggests that exposure to secondhand smoke significantly predicts deviate behavior in later childhood.

Pagani said the latest study is the first to account for other factors like whether children were exposed to smoke in the womb and parent's own antisocial behavior.

"Previous studies looking at groups of children have generally asked mothers whether they smoked or not, and how much at each follow-up, rather than asking whether someone smoked in the home where young children live and play," Pagani explained.

"Furthermore, few studies have looked at antisocial behavior in the parents and even fewer have investigated the subsequent influence of prolonged exposure to secondhand smoke over the long term. None have taken into account the fact that disadvantaged families are less likely to participate in a long study like this one, which of course skews the statistics," she added.

Researchers said that the latest findings are also backed by previous biological studies into the effects of smoke on the brain.

Researchers said that 85 percent of second hand smoke is made up of sidestream smoke emanated from a burning cigarette and 15 percent is made up of inhaled and then exhaled mainstream smoke. Experts said sidestream smoke is more harmful than mainstream smoke because it contains higher concentrations of toxins and pollutants over a longer exposure period.

"We know that the starvation of oxygen caused by smoke exposure in the developing central nervous system can cause low birth weight and slowed fetal brain growth," Pagani said. "Environmental sources of tobacco smoke represent the most passive and preventable cause of disease and disability."

"This study suggests that the postnatal period is important for the prevention of impaired neurobehavioral development and makes the case for the promotion of an unpolluted domestic environment for children," she concluded.