Early childhood exposure to secondhand tobacco smoke may cause greater health impacts in girls than their male counterparts, new findings suggest.
University of Cincinnati researchers found that lung function in girls who were exposed to tobacco smoke was six times worse than the boys who had the same level of exposure to smoke and allergic sensitization.
The study which involved 476 kids also disclosed that those who were exposed to high levels of secondhand smoke and also had allergic sensitizations at age 2 were at a higher risk of decreased lung function at the age of 7. 
“Our study shows that the timing of allergic sensitization is crucial because children who are sensitized by age 2 are more likely to suffer the greatest lung deficits during childhood as a result of secondhand-smoke exposure,” said co-author and researcher Kelly Brunst.
“This association was not observed at age 4 or 7, emphasizing the importance of this critical window for lung development,” added Brunst whose study is published in the journal Pediatric Allergy and Immunology.
“It’s likely that the complex interaction between secondhand smoke and pulmonary [lung] function loss in boys and girls is ultimately dependent on the timing of exposure as well as the child’s ‘total load’ in relationship to cumulative risk factors — exposures, allergic sensitization, asthma status, genetic susceptibility and sex hormones,” said lead investigator Grace LeMasters.
