Millions of U.S. children and adolescents could have deficits in reading and other skills caused by breathing secondhand smoke, researchers estimate. A new study links poor performance on several cognitive tests to tobacco-smoke exposure, even at low levels.
Past studies identified intellectual and behavioral problems in children of parents who smoked but didn't determine the pervasiveness of exposure or the consequences of different degrees of exposure. Also, most previous research didn't separate the effects of exposure in the womb from those of breathing tobacco smoke during childhood.
To fill these gaps, Kimberly Yolton of Cincinnati Children's Hospital Medical Center and her colleagues sifted data from a large study of the U.S. kids' health.