THURSDAY, April 4 (HealthDay News) -- There has been a big drop in the number of American children with elevated blood lead levels over the past four decades, but about 2.6 percent of children aged 1 to 5 years still have too much lead in their systems, federal officials reported Thursday.
An estimated 535,000 children in that age group had blood lead levels at or above 5 micrograms per deciliter (mcg/dL) in 2007 to 2010, according to an analysis of data from the U.S. National Health and Nutrition Examination Survey.
A lead level at or above 5 mcg/dL is considered "a level of concern" by the U.S. Centers for Disease Control and Prevention. This level was adopted by the CDC in 2012.
One expert said the new numbers remain worrisome.
"We have made extraordinary progress against childhood lead poisoning in the United States over the past two decades," said Dr. Philip Landrigan, director of the Children's Environmental Health Center at the Mount Sinai Medical Center, in New York City. However, "despite this success, lead poisoning is still epidemic in American children," he added.
The consequences of lead transmitting from the environment to children can be dire, added Landrigan, who was not involved in the new report. He said that the 535,000 children cited in the report are vulnerable to "brain damage with loss of IQ, shortening of attention span and lifelong disruptions in their behavior as a direct result of their exposure to lead."
"Because the brain damage caused to children by lead is permanent, untreatable and extremely costly, prevention of lead exposure is the only logical and medically proven approach for dealing with the lead poisoning epidemic," Landrigan said.
The CDC noted that previous "level of concern" for blood lead levels in children was set at or above 10 mcg/dL. The new study found significant progress over the past four decades in reducing the number of children with this level of lead in their blood.
From 1976 to 1980, an estimated 88 percent of children aged 1 to 5 had blood lead levels at or above 10 mcg/dL, compared with 4.4 percent in 1991-1994, 1.6 percent in 1999-2002 and 0.8 percent in 2007-2010.
However, there are persistent differences in the blood lead levels of children in different racial/ethnic and income groups that are linked to disparities in housing quality, environmental conditions, nutrition and other factors, the study said.
Efforts to prevent lead poisoning should target areas and communities where children are most at risk, the study authors recommended in the April 5 issue of the CDC's Morbidity and Mortality Weekly Report.
Another expert not involved with the report described what parents can do.
"Parents may help protect their children by ensuring that their home environments are free of lead-based paint and by keeping children away from old windows and areas with peeling paint," said Dr. Roya Samuels, a pediatrician at Cohen Children's Medical Center in New Hyde Park, N.Y.
"Maintaining a clean home and encouraging frequent hand-washing are good preventative measures as well," Samuels said. "A healthy, well-balanced diet including foods rich in calcium and iron will also help children absorb less lead if exposed to the toxic metal."
Over the past decades, nationwide efforts to reduce lead levels in children have included removing lead from gasoline, eliminating lead paint in homes, reducing lead levels in children's products and screening those at high risk.
The Nemours Foundation has more about children and lead.