Exposure to Tobacco May Increase Risk of ADHD

Scientists at the Cincinnati Children's Hospital Medical Center have determined in a new investigation that children who are prenatally exposed to high levels of lead or tobacco smoke run a much higher risk than others of developing ADHD. The attention deficit hyperactivity disorder is a condition that many children today are suffering from, even though its causes and triggers are not precisely known at this point. The investigation also seems to point out that more than 35 percent of existing ADHD cases in children aged eight to 15 may be cured if these two factors disappear, PhysOrg reports.

Some official numbers show that, if this were to happen, then the number of children suffering from ADHD could be reduced by as much as 800,000. Full details of the research appear in the November 23 issue of the scientific journal Pediatrics. “Tobacco and lead exposure each have their own important adverse effect. But if children are exposed to both lead and prenatal tobacco, the combined effect is synergistic,” CCHMC Division of Developmental and Behavioral Pediatrics physician Tanya Froehlich, MD, explains. She has also been the lead author of the new journal entry.

“Although we tend to focus on ADHD treatment rather than prevention, our study suggests that reducing exposures to environmental toxicants might be an important way to lower rates of ADHD,” the senior author of the research, Robert Kahn, MD, MPH, adds. The expert is also a physician and a researcher at Cincinnati Children's. After the careful analysis of study results, it was made apparent that children who had been exposed to nicotine were at a 2.4 times higher chance of developing ADHD, as opposed to their peers, who had not been exposed to the same conditions.

The risk of developing the condition was found to be up to eight times greater for children exposed to both lead and nicotine than for their peers. The correlation stood even if the lead levels in participants' blood samples did not exceed the action level of ten micrograms per deciliter, set up by the US Centers for Disease Control and Prevention (CDC). The investigation is based on data of a representative population sample, collected between 2001 and 2004, in the National Health and Nutrition Examination Survey (NHANES). The survey was carried out by the National Center for Health Statistic, a division of CDC.