Passive smoking can make kids aggressive and antisocial

Kids who are exposed to secondhand smoke in early childhood are more likely to grow up to be physically aggressive and antisocial, a new study has warned.
Researchers from University of Montreal in Canada found that aggressive behaviour in kids was linked specifically to secondhand smoke exposure in childhood regardless of whether they were exposed during pregnancy or their parents have a history of being antisocial.
"Secondhand smoke is in fact more dangerous that inhaled smoke, and 40 per cent of children worldwide are exposed to it. Moreover, exposure to this smoke at early childhood is particularly dangerous, as the child's brain is still developing," said researcher Linda Pagani.

"I looked at data that was collected about 2,055 kids from their birth until ten years of age, including parent reports about secondhand smoke exposure and from teachers and children themselves about classroom behaviour.
"Those having been exposed to secondhand smoke, even temporarily, were much more likely to report themselves as being more aggressive by the time they finished fourth grade," Pagani said.
Pagani relied on longitudinal data collected by Quebec health authorities from birth onward on an annual basis.

Although no direct causal link can be determined, the statistical correlation suggests that secondhand smoke exposure does forecast deviant behaviour in later childhood, the study found.

The very detailed information collated for the Quebec Longitudinal Study of Child Development enabled Pagani to do something no other researcher has done to date: distinguish the unique contribution of secondhand smoke exposure on children's later deviant behaviour.
"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 said.
"Furthermore, few studies have looked at antisocial behaviour 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," Pagani said.
The study was published in the Journal of Epidemiology and Community Health.