Children with lead levels lower than the U.S. standard may still suffer lower IQs or other problems, a government advisory panel said Thursday as it urged doctors to be more alert to lead poisoning signs.
The warning, from the U.S. Centers for Disease Control and Prevention, comes amid concerns over imported toys with lead.
The CDC has never set a threshold for what defines lead poisoning. But it created a standard of sorts in 1991 when it said a lead level of 10 micrograms per deciliter of blood should prompt a doctor to assess the child's environment and take other steps.
"You can have toxicity at levels all the way down to zero," said Dr. Morri Markowitz, director of the pediatric environmental sciences clinic at New York City's Montefiore Medical Center. He was not involved in the report.
Lead poisoning can cause learning disabilities and behavioral problems and, at high levels, seizures, coma and death.
Ten micrograms has become the number doctors use when deciding to refer a child for further attention.
This is the first time the Advisory Committee on Childhood Lead Poisoning Prevention has focused on risks to children with lower lead levels, said Dr. Helen Binns of Northwestern University, primary author of the report. The panel isn't proposing a new standard, she said, but is "emphasizing that all levels are important."
Children with blood lead levels below 10, or even those up to 20, exhibit no obvious symptoms. But scientists believe intellectual development may be affected at lower levels.
The new report was driven by recent research that indicated differences in intellectual development of children with measurable levels of lead poisoning as compared with other kids.
There's no treatment proven effective at reducing these lead levels in children, said Mary Jean Brown, chief of the CDC's lead poisoning prevention branch.