Secondhand smoke ups kids' antisocial behavior risk

Canadian study makes the case for the promotion of an unpolluted domestic environment for children.

By JUDY SIEGEL-ITZKOVICH
Smoking cigarette 370 (photo credit: Daniel Munoz/Reuters)
Smoking cigarette 370
(photo credit: Daniel Munoz/Reuters)
Children that are exposed to secondhand smoke in early childhood are more likely to grow up to be physically aggressive and antisocial – regardless if they were exposed during pregnancy or their parents have a history of being antisocial – researchers at the University of Montreal published in the Journal of Epidemiology and Community Health.
Researchers Dr. Linda Pagani and Caroline Fitzpatrick said that no study to date had controlled for these factors.
“Secondhand smoke is in fact more dangerous than inhaled smoke and 40 percent of children worldwide are exposed to it,” Pagani said.
Sidestream smoke, which emanates from a burning cigarette and comprises 85 percent of secondhand smoke, contains a higher concentration of many dispersed respirable pollutants than the inhaled-and-then-exhaled mainstream smoke.
“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 10 years of age, including parent reports about secondhand smoke exposure and from teachers and children themselves about classroom behavior. 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.”
Asked to comment, Prof. Alan Apter – head of psychological medicine at Schneider Children’s Medical Center in Petah Tikva – said that “I think that this is yet another indication of the hazards of smoke exposure on the developing brain and thus adds to a mass of compelling evidence that smoking and secondhand exposure should be as limited as possible.”
Apter continued that identifying children in this category can also shed light on additional detrimental environmental factors that would affect their psychological well-being.
“It is possible that exposure to secondhand smoke is a marker for being disadvantaged and goes in hand with other deleterious effects of adversity such as stress, poor general health and more psychopathology in the parents.”
Since it would be unethical to expose children to secondhand smoke, Pagani relied on longitudinal data collected by Quebec health authorities from birth onward on an annual basis. Parents went about raising their children while participating in the study and the data provided a natural experiment of variations in the child population of household smoke exposure throughout early childhood. Although no direct causal link can be proven, the statistical correlation suggests that secondhand smoke exposure does forecast deviant behavior in later childhood, the authors wrote.
The detailed information collated for the Quebec Longitudinal Study of Child Development enabled Pagani to do something no other researcher had done to date – distinguish the unique contribution of secondhand smoke exposure on children’s later deviant 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,” she said.
Pagani said that past studies rarely took into account antisocial behavior in the parents, prolonged exposure to secondhand smoke and that disadvantaged families are less likely to participate in long term studies.
“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 neuro-behavioral development and makes the case for the promotion of an unpolluted domestic environment for children.”
Pagani said this is yet another indication of the hazards of smoke exposure on the developing brain and thus adds to a mass of compelling evidence that smoking and secondhand exposure should be as limited as possible.