According to a new study, secondhand smoke (also known as passive smoking) may be tied to a greater risk of attention deficit hyperactivity disorder (ADHD) and learning disabilities in children.
The study — funded by the Centers for Disease Control and Prevention (CDC) and the National Center for Health Statistics — finds that children exposed to secondhand smoke in the home are twice as likely to develop either ADHD or a learning disability. The researchers found that approximately 6 percent of children ages 11 and younger — 5 million American children — are regularly exposed to cigarette or tobacco smoke in their homes.
Researchers from the Harvard School of Public Health examined health data generated by a 2007 national survey. They analyzed the responses of the U.S. parents of guardians of over 50,000 children ages 11 and younger.
The researchers found that in smoking homes, children had a learning disability 8.2 percent of the time, ADHD nearly 6 percent of the time, or another conduct disorder 3.6 percent of the time.
Treatment costs associated with treating a child with a mental disorder or learning disability is estimated to be over $14,000 per year. On a national level, that comes out to be about $9.2 billion each year, the study noted.
The researchers could not determine a causal relationship between secondhand smoking and a child getting either ADHD or a learning disability. However, the authors noted, “Assuming a causal relationship, 274,100 excess cases of these disorders could have been prevented had the children not been exposed to secondhand smoke in their homes.”
An earlier report from the National Center for Addiction and Substance Abuse found that 9 out of 10 people who are substance abusers began smoking, drinking or using other drugs before they turned 18.
Another new study suggests that children who are exposed to secondhand smoke are more likely to become smokers themselves. This study, by Christina N. Lessov-Schlaggar, Ph.D., and colleagues, looked at over 200 preteens’ smoking attitudes and behaviors.
The new study was published in the journal Pediatrics.