Some children in the United States are still at risk for lead poisoning

May 10 2005

Despite efforts to remove lead from many products, such as gasoline and paint, some children in the United States are still at risk for lead poisoning. A new study shows that children at the greatest risk for lead poisoning, and also those identified with elevated blood lead levels through screening, were the least likely to get follow-up testing needed for prevention.

In the first population-based study of its kind, researchers from the University of Michigan Health System's Child Health Evaluation and Research (CHEAR) Unit found that only 53.9 percent of children in Medicaid with elevated blood lead levels identified through screening got the necessary follow-up testing to prevent lead poisoning, and of those children, nearly half still had elevated blood lead levels.

The results of this study are published in the May 11, 2005 issue of the Journal of the American Medical Association (JAMA).

Significant efforts have been made by the Centers for Disease Control and Prevention and state health departments to improve blood lead screening among 1- to 5-year-old children at the greatest risk for lead poisoning – those enrolled in Medicaid or other public assistance program, or living in communities known to have higher levels of lead in the environment.

But screening is only one step in the process to prevent lead poisoning, which even at low levels can impair cognitive development and cause anemia, says lead author Alex R. Kemper, M.D., MPH, a member of the CHEAR team in the U-M Division of General Pediatrics.

"Screening children for lead is so important because its symptoms are not physical. But it's only effective with appropriate follow-up testing," says Kemper, an assistant professor of pediatrics at the U-M Medical School. "Follow-up testing is the cornerstone of lead poisoning management and an essential component of secondary prevention, and kids aren't making it to that necessary next step."

Using a group of 3,682 Michigan Medicaid-enrolled children under the age of 6 with an elevated blood lead level screening, Kemper and his team set out to determine if children were receiving the necessary follow-up testing within 180 days of their screening. The six-month interval following an elevated screening is critical to determine if blood lead levels are increasing and if the child is responding to any medical intervention.

The study was based in Michigan since the state has a reporting mechanism for all blood lead levels, and compared to other states, Michigan has a higher number of children with lead poisoning.

Most children in the study were Hispanic or non-white, lived in urban areas and had a high risk of lead exposure. More than half in the study were 1-year-old and 2-year-old children.

The study found that a little more than half (53.9 percent) of the children received follow-up testing. Of those who had follow-up testing, testing occurred an average of 69 days after screening revealed the elevated blood lead level, and 47.5 percent continued to have an elevated blood lead level.

But the children initially at the highest risk for lead poisoning or exposure were the least likely to get follow-up testing after a blood lead level screening.

In fact, the study showed the likelihood for follow-up testing was lower for Hispanic or non-white children, children living in urban areas, and children with a high risk for lead exposure.

Most revealing is that among those children who did not have follow-up testing, 58.6 percent had at least one medical encounter during the 180 days following the elevated screening blood lead level.

While the majority of these visits were for evaluation and medical care management, more than 13 percent had at least one visit for preventive care and more than 26 percent had an emergency department visit – all of which account for missed opportunities for follow-up testing, Kemper says.

"Based on this study, we know kids are not getting the care they need to prevent lead poisoning, but it doesn't tell us the specific reasons as to why follow-up testing is not occurring," says Kemper. "More research is still needed to best understand the specific barriers to optimal care for children with elevated screen blood lead levels and to clearly define the responsibilities of public and private health care providers."

In addition to Kemper, the study was co-authored by Lisa M. Cohn, MS; Kathryn E. Fant, MPH; and Kevin J. Dombkowski, DrPH, with the Child Health Evaluation and Research (CHEAR) Unit in the Division of General Pediatrics at the U-M Health System; and Sharon R. Hudson, RN, MSN, CNM, coordinator, Childhood Lead Poisoning Prevention Program in the Michigan Department of Community Health.