Aggressive behavior linked specifically to secondhand smoke exposure in childhood

Children who are exposed to secondhand smoke in early childhood are more likely to grow up to physically aggressive and antisocial, regardless of whether they were exposed during pregnancy, according to Linda Pagani and Caroline Fitzpatrick.

“Secondhand smoke is in fact more dangerous that inhaled smoke, and 40% 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,” Pagani said. “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 time they finished fourth grade.”

Given that it would be unethical to exposure children to secondhand smoke, Pagani relied on longitudinal data collected birth onward on an annual basis. The data provided a natural experiment of variations in the child population of household smoke exposure throughout early childhood. The statistical correlation suggests that secondhand smoke exposure does forecast deviant behavior in later childhood. The very detailed information collated enabled her to do something no other researcher has done to date: distinguish the unique contribution of secondhand smoke exposure on children’s later deviant behavior. Dr. 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.

The statistics are backed by other biological studies into the effects of smoke on the brain. Secondhand smoke comprises 85% sidestream smoke emanated from a burning cigarette and 15% inhaled and then exhaled mainstream smoke. Sidestream smoke is considered more toxic than mainstream smoke because it contains a higher concentration of many dispersed respirable 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,” Dr. 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.

Source: Science daily

N.H.Kh