Passive Smoking Leads to Aggressive Behaviour in Children

A new study by researchers at the University of Montreal revealed that children who are exposed to second-hand smoke from early childhood tend to be physically aggressive and anti-social once they grow up. This finding according to the researchers is regardless of whether they were exposed during pregnancy or their parent's have a history of being antisocial.

The study was conducted by Linda Pagani and Caroline Fitzpatrick and the university's affiliated CHU Sainte-Justine hospital. It was published in Journal of Epidemiology and Community Health on 21 May.

According to pagani, second-hand smoke is more dangerous than inhaled smoke and around 40 percent of the world's children are exposed to it. "Exposure to this smoke at early childhood is particularly dangerous, as the child's brain is still developing," she said in a statement published on the university's news site.

"I looked at the 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 class room 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." 

Second-hand smoke encompasses 85 percent of sideline smoke which is considered to be more toxic than mainstream smoke, because of its higher concentration of pollutants. The other 15 percent comprises of the inhaled and exhaled mainstream smoke.

For the study, Pagani said she relied on longitudinal data collected by health authorities from birth onwards on an annual basis. This detailed data collection from the 'natural experiment' enabled Pagani to distinguish the unique contribution of second-hand smoke exposure on children's deviant behaviour later in their lives. 

The study's findings calls for the need of an unpolluted environment for children, as it proposes postnatal period to be the most important time for the prevention of impaired neurobehavioural development in them.