TUESDAY, May 10, 2005 (HealthDay News) -- Children who show high levels of lead in their blood during routine screenings often don't get the necessary follow-up tests to make sure those lead levels are coming down, researchers report.
Only 54 percent of children with elevated lead levels received follow-up testing within six months, putting them at risk for cognitive impairment, according to a study in the May 11 issue of the Journal of the American Medical Association.
Even more alarming, said one of the study's authors, Dr. Alex Kemper, is that "the higher the risk children had in the first place, the less likely they were to have follow-up testing." Kemper is an assistant professor of pediatrics at the University of Michigan in Ann Arbor.
While the number of children with lead poisoning has dropped dramatically since lead was banned in paint and gasoline, about 2 percent of America's children still test positive for high levels of lead in their blood. And, according to Kemper, low-income children on Medicaid are at a three-fold increased risk of high blood levels of lead.
Excess levels of lead, even at low amounts, can cause anemia and impair cognitive development, Kemper said. He added that signs of excessive lead contamination aren't always physically apparent -- which is why screening is so important.
Screening for lead used to be done on all children because it was so prevalent in the environment. In 1997, the U.S. Centers for Disease Control and Prevention changed its recommendations for screening, and suggested that only at-risk children needed to be screened because many sources of environmental lead, such as paint and gasoline, had been eliminated.
Two specific groups remain at highest risk, according to an accompanying editorial in the journal: Children who live in poorly maintained rental properties, often in urban areas, and more affluent children who live in older homes that are being renovated. The predominant sources of lead exposure are lead-based paint, which contaminates indoor dust, and traces of the element in water from lead used in plumbing, according to Dr. Bruce Lanphear, director of Cincinnati Children's Environmental Health Center, and the editorial's author.
For the study, Kemper and his colleagues concentrated on 3,682 children under 6 years old enrolled in the Medicaid program.
The children were tested between January 2002 and June 2003. All of the children had a screening blood lead level of more than 10 micrograms per deciliter, a level that is considered elevated.
Generally, Kemper said, follow-up testing should be done within three months of an elevated test. The researchers determined that follow-up testing had taken place if it was performed within 180 days of the initial blood lead screening, he said.
The researchers found that only 53.9 percent of the children with elevated lead levels received the necessary follow-up testing.
Race had a slight effect on the likelihood of follow-up, with white children about 9 percent more likely to get follow-up screening. Where the children lived also affected follow-up rates, with urban children about 8 percent less likely to get follow-up checks.
Children most at risk of high lead levels were 6 percent less likely to receive follow-up testing than those at low risk, the study found.
Kemper said the researchers initially thought the children weren't getting the follow-up tests because they didn't have the opportunity or the resources to see their health-care provider. But the researchers found that almost 60 percent of those who didn't receive follow-up testing had at least one visit with a health professional after the initial screening.
"The main thrust of this study is to highlight a typical practice -- not identifying kids with elevated lead levels often enough, and then when we do, failing to follow-up and do adequate testing," said Lanphear.
"We're really just failing children again," said Lanphear, who added that other countries moved to ban lead in paint long before the United States did. He said as long as 100 years ago, other countries recognized that lead was toxic, and as early as 1909 some European countries started banning the substance.
Lanphear said education efforts aren't enough, and regulations are needed to further protect children from lead poisoning. He suggested that homes be screened for lead before they are sold. He also said it's "time to revisit the EPA (Environmental Protection Agency) standards to make sure they're adequate to protect children and pregnant women."
Kemper advised that parents living in an older home get their children tested for lead poisoning. They should also contact their local health department to find out what services are available locally to test for -- and remove -- lead in the home.
For more information on the health effects of lead and how to reduce lead exposure, visit the U.S. Environmental Protection Agency.