Although the exact cause of attention-deficit/hyperactivity disorder (ADHD) has not yet been determined, a new study provides evidence that tobacco and lead exposure may increase a child's risk of developing the condition.
In a study published online ahead of print in Pediatrics, researchers assessed data from the 2001-2004 National Health and Nutrition Examination Survey. A total of 2,588 children aged 8 to 15 years were included in the final analysis. The researchers assessed prenatal tobacco exposure through reports of maternal cigarette use during pregnancy and childhood lead exposure through measurement of current blood lead levels. They found that 8.7% of the children met the diagnostic criteria for ADHD. Children with prenatal tobacco exposure and childhood lead exposure had a higher risk of ADHD (adjusted odds ratios, 2.4 and 2.3, respectively). Children who were exposed to both tobacco and lead had an even greater risk of ADHD (adjusted odds ratio, 8.1).
The authors suggested that, based on these results, reduction of exposure to tobacco and lead may be an important step in preventing ADHD.