"This study shows that certain groups of children have an increased sensitivity to environmental exposures," says Tanya Froehlich, M.D., a physician at Cincinnati Children's and the study's lead author. "More studies like this one are needed to help set exposure standards that adequately protect the most susceptible members of society."
The study will be presented at 10:15 a.m. Pacific time Monday, May 1, at the annual Pediatric Academic Societies meeting in San Francisco.
The Cincinnati Children's researchers examined the impact of lead exposure on executive function the ability to plan and organize activities and behaviors. Executive function is impaired in individuals with ADHD. They particularly wanted to determine whether lead's effects are influenced by an individual's underlying genetic and biological make-up, including the impact of gender and variations in the DRD4 dopamine receptor gene. The DRD4 receptor helps regulate brain levels of dopamine, a chemical in the brain that is essential for attention and cognition, and variations in DRD4's composition have been linked to ADHD.
The study findings indicate that increasing lead exposure is linked to impairment on a number of executive functions, including planning, memory span and attentional flexibility (the ability to revise one's plan or strategy in the face of obstacles or new information). However, certain genetic and biological factors seemed to predispose an individual to the negative effects of lead exposure. For instance, only children with certain variations of the DRD4 gene seemed vulnerable to lead's adverse effects on atten
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Contact: Jim Feuer
jim.feuer@cchmc.org
513-636-4656
Cincinnati Children's Hospital Medical Center
1-May-2006