Screening For Lead Poisoning Does Not Appear Effective When No Symptoms Are Present: Study

A group of leading experts indicating that it is unclear whether children or pregnant women should be screened for lead poisoning if they do not already show symptoms.

The U.S. Preventative Services Task Force published findings of an investigation into screening for elevated blood levels in asymptomatic children and pregnant women in the Journal of the American Medical Association (JAMA) on April 16, indicating that the independent panel of medical experts could not reach a conclusion on whether such testing was helpful.

The researchers looked at data on 24 studies, but none of the studies directly evaluated the benefits or harms of screening vs. no screening for children for elevated lead levels in their blood.

According to the findings, screening questionnaires did not help identify children who did not show symptoms of lead poisoning but may have had elevated blood levels. The study also found that chelation therapy, used to separate and remove lead from blood, did not appear to have sustained effects on lowering childhood blood lead levels. However, those who received chelation appeared to be slightly shorter than their peers, and had slightly poorer cognitive outcomes.

“Screening questionnaires were not accurate for identifying children with elevated blood lead levels,” the researchers concluded. “Chelating agents in children were not significantly associated with sustained effects on blood lead levels but were associated with harms.”

Lead poisoning among children has been a serious health concern nationwide for decades, as it is known to increase the risk of nervous system injury, brain damage, seizures or convulsions, growth or mental retardation, coma and even death. Childhood lead poisoning is considered the most preventable environmental disease among young children.

The U.S. Centers for Disease Control and Prevention (CDC) estimate that 535,000 children ages 1-5, or about 2.6% of such children in the U.S., have levels of lead in their blood that place them at risk for adverse health effects. To come up with that number, the CDC analyzed data from the National Health and Nutrition Examination Survey from the years 1999 to 2002, and 2007 through 2010.

Childhood lead poisoning is considered the most preventable environmental disease among young children. More than half a million children in the U.S, have lead blood levels above 5 micrograms per deciliter, the “level of concern” reference set by the CDC.