What to Know About Lead Poisoning in Children

How do I know if my children have high blood-lead levels?

Lead exposure can go unnoticed until levels accumulate, doctors say. High levels of lead can result in stomach pain, vomiting, fatigue, learning difficulties, developmental delays and even seizures.

Pediatricians recommend blood tests for infants and toddlers who live in homes built before 1978 or have other risk factors. Medicaid programs and some states require screening, but it is not typically advised for children older than 3.

While officials have said there is no safe level of lead, parents do not automatically need to worry if traces of lead show up in a child’s blood test. The average blood-lead level among young U.S. children is under 1 microgram per deciliter of blood. “I don’t think they should be worried at all,” said Kim Dietrich, a professor emeritus of epidemiology and environmental health at the University of Cincinnati College of Medicine.

Studies finding I.Q. score deficits and links to A.D.H.D. tend to focus on children with levels at 5 and above. According to the C.D.C., about 95 percent of children in the United States have lead levels under 3.5 micrograms per deciliter of blood.

Some experts have even begun to question the C.D.C.’s position that there is “no safe level” of lead, given its ubiquitous nature and the minor effects that low levels have had on millions of children in the United States.