Lead exposure linked to ADHD

CINCINNATI, May 5 (UPI) -- A U.S. researcher says a study has linked childhood lead exposure to attention-deficit hyperactivity disorder, or ADHD.

The study estimated that lead levels of more than 1.3 micrograms per deciliter may account for more than 500,000 cases of ADHD among children ages 8 to 15 nationwide.

Dr. Tanya Froehlich of Cincinnati Children's Hospital Medical Center examined data on 2,704 children from the 2001 to 2004 National Health and Nutrition Examination Survey.

Froehlich said children with the highest levels of lead exposure had a more than two-fold increased risk of ADHD compared to children with the lowest lead levels.

The findings were presented at the Pediatric Academic Society annual meeting in Honolulu.

ADHD symptoms include: impulsiveness, hyperactivity, talking when others are talking, inattention, daydreaming and loss of focus.