ADHD Risk Increases With Exposure To Lead, TobaccoNov 24, 2009 | Parker Waichman LLP An emerging study has found a link to attention-deficit/hyperactivity disorder (ADHD) in children exposed in-utero to tobacco smoke and during childhood to lead. The research was conducted at Cincinnati Children's Hospital Medical Center, reported Science Daily.
The National Institute of Mental Health (NIMH) describes ADHD as involving difficulty staying focused, paying attention, and controlling behavior, and hyper- or over-activity.
According to the research, about 35 percent of childhood ADHD cases involving children between eight and 15 years of age could be minimized by removing exposure to lead and tobacco, said Science Daily. The change could affect about 800,000 children. "Tobacco and lead exposure each have their own important adverse effect," said Tanya Froehlich, M.D., a physician in the Division of Developmental and Behavioral Pediatrics at Cincinnati Children's and lead study author. "But if children are exposed to both lead and prenatal tobacco, the combined effect is synergistic," quoted Science Daily. The study appears in the online, November 23 issue of Pediatrics.
"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," said Robert Kahn, MD, MPH., a physician and researcher at Cincinnati Children's and the study's senior author, reported Science Daily.
According to the research, children exposed to tobacco smoke when in the womb were 2.4 times likelier to be diagnosed with ADHD; children with blood lead levels in the top third experienced a 2.3-fold increase of ADHD, said Science Daily. Of note, these levels are considered well below the U.S. Centers for Disease Control and Prevention’s (CDC) action level of 10 micrograms per deciliter. The team also found that the risk of ADHD increased by an astounding eight-fold for children exposed to both tobacco and lead, versus children not exposed to either contaminant, said Science Daily.
The study looked at information on eight-to-15-year-olds from 2001 through 2004 derived from the National Health and Nutrition Examination Survey (NHANES), which was from the National Center for Health Statistics at the Centers for Disease Control and Prevention, said Science Daily. NHANES is a nationally representative sample of the U.S. population and was created so that information about the health and diet of Americans can be collected and analyzed. About 8.7 percent of the 3,907 children in the study met the diagnostic criteria for ADHD.
Yesterday we wrote than a new report found a link between phthalate concentrations in urine to ADHD, citing Science Daily. Phthalates are chemicals that make plastics and vinyls more flexible. The study found a noteworthy link between phthalate metabolite levels in urine to ADHD test results and symptoms, with increased symptoms connected to increased levels, said Science Daily.
Earlier this year we wrote that another study revealed that stimulant medications used to treat ADHD could increase the risk of sudden cardiac death in children, yet the Food & Drug Administration (FDA) opted not to change its recommendations on the way in which such drugs are prescribed. Labeling for drugs like Ritalin, Adderall, Dexedrine, and Concerta already include warnings about the risk of sudden cardiac death in patients with heart problems, but are considered safe for children without pre-existing heart conditions. There have been worries, however, that such stimulants could be risky in children with undiagnosed heart problems. It is not known how often cardiac events occur in children taking these drugs.