ADHD Linked To Lead Exposure And Smoking During Pregnancy
About one third of ADHD cases in the United States are probably linked to the mother smoking during pregnancy and exposure to lead during childhood, say researchers from Cincinnati Children's Hospital Medical Center.
(ADHD = Attention Deficit Hypera
You can read about this new study in the journal Environmental Health Perspectives.
Bruce P. Lanphear and team wanted to examine the link between exposures to tobacco smoke and environmental lead and ADHD.
Information on 4,704 children, aged 4-15, was examined by the researchers. This total included 4.2% who suffered from ADHD. They found that a child whose mother smoked while he/she was in her womb is 2.5 times more likely to develop ADHD than a child whose mother had not smoked while she was pregnant.
They also found that a child whose lead blood levels were over 2 micrograms per deciliter had a 4 times higher likelihood of having ADHD, when compared to a child whose lead blood levels were under 0.8 micrograms per deciliter.
About 300,000 kids under five in the USA have lead blood levels above the nationally acceptable limit of 10 micrograms per deciliter.
If the 4.2% of children out the 4,704 had ADHD - we could extrapolate that 1.8 million American kids under 15 have ADHD. Current estimates for ADHD among US children range from 3% to 8%.
"Exposures to Environmental Toxicants and Attention Deficit Hyperactivity Disorder in US Children"
Joe Braun, Robert S. Kahn, Tanya Froehlich, Peggy Auinger and Bruce P. Lanphear
doi:10.1289/ehp.9478 (available at http://dx.doi.org/) Online 19 September 2006
Environmental Health Perspectives