When lead was taken out of products like paint and gasoline, levels of the metal in the blood of U.S. children dropped. But the American Academy of Pediatrics says the problem is not over.
"Most existing lead standards fail to protect children," members of the AAP's environmental health council report in a statement published Monday in the journal Pediatrics. Standards for the amount of lead that can be present in paint, water, dust and soil are not based on health standards, the pediatricians say, but instead on what's been feasible to attain. Such standards, they write, create "an illusion of safety."
"We've taken lead out of the paint and out of the gasoline, but the history is still present," says Dr. Jennifer Lowry, a co-author of the academy's report and a medical toxicologist with Children's Mercy, a hospital in Kansas City, Mo.
Older homes with paint and plumbing from earlier time, or homes that stand on what was once an industrial site, can have contaminated dust, water and soil. When children ingest those materials, the metal can get into their bloodstream.
Human bodies have no use for lead, but it can be mistaken for calcium or iron, settling in bones and disrupting important biological processes. And children's bodies absorb more lead than adult bodies do.
"Lead is a neurotoxin," Lowry says. "It gets into the brain and it can cause damage."
It's unethical, of course, to purposefully poison kids with varying amounts of lead and then see what happens with their blood lead level and how that corresponds to developmental problems. So it's hard to say what the effect of exposure to low levels of lead is for an individual child. But on a population level, low-level lead exposure has been shown to affect IQ, attention and behavior. By some estimates, preventing children from coming into contact with lead would prevent the loss of more than 20 million IQ points.
According to the Centers for Disease Control and Prevention, if a child's blood has more than 5 micrograms of lead per deciliter of blood, it's a red flag for health care providers. It means that child is in the 2.5 percent of children in the country with the highest levels of lead in the blood.
"But at that point, when we find out that they have an elevated lead level, the harm has already been done," Lowry says. "We cannot have our children be canaries in the coal mine, where they get exposed first and then we have to try to fix it. If we want to actually do the right thing, we should prevent it from happening in the first place."
The academy recommends that pediatricians and primary care providers proactively test children for high blood lead levels, especially if they are between 1 and 2 years old and live in areas with homes built before 1960. It's also calling for updated national limits for lead in house dust, water and soil, and for federal funding for initiatives like removing lead paint and dust from public housing and replacing the lead service lines that bring water into many homes.
"We should know where the old houses are that were built before 1960, where the soil is next to the highways, where we have these lead problems and actually fix it before we send our kids out to live in those environments," says Lowry.
An estimated 37 million homes in the United States still contain lead-based paint. An additional 6 million homes receive their drinking water through lead pipes.
DAVID GREENE, HOST:
All right, there's growing concern about the amount of lead children can safely be exposed to. Some researchers now say the only acceptable amount is none at all. They're calling for stricter regulations on lead children can encounter in water, dust and soil. Here's NPR's Rae Ellen Bichell.
RAE ELLEN BICHELL, BYLINE: When lead was taken out of many products over the last few decades, levels of the metal in U.S. children's blood plummeted. But the American Academy of Pediatrics says the problem is not over.
JENNIFER LOWRY: We have taken the lead out of the paint and we have taken lead out of the gasoline, but the history is still present.
BICHELL: That Dr. Jennifer Lowry. She's a medical toxicologist with Children's Mercy, a hospital in Kansas City, Mo. She's one author on a statement out today in the journal "Pediatrics" that calls for lower limits on the amount of lead allowed in homes, schools and yards. When children breathe in or swallow material with lead in it, the metal can get into the bloodstream. The body can mistake it for calcium or iron, potentially allowing lead to settle into bones or to disrupt important processes. Some lead used to be considered OK.
LOWRY: It kind drives me crazy when people say well, they have a normal lead level. Well, no, they don't have a normal lead level. The normal lead level is zero.
BICHELL: Low-level lead exposure is known to affect behavior and learning. By some estimates, preventing children from coming into contact with lead would prevent the loss of more than 20 million IQ points. According to the CDC, if a child's blood level is more than five, it's a red flag for health care providers. But Lowry says at that point, the harm's already done.
LOWRY: We cannot have our children be canaries in the coal mine where they get exposed first, they get the poison and then we have to try to fix it. If we want to actually do the right thing, we should prevent them from happening in the first place.
BICHELL: The academy is calling for more proactive testing of children's blood. It has also recommended funding by the federal government for initiatives like removing lead paint and dust from public housing and replacing the lead service lines that bring water into many homes. Rae Ellen Bichell, NPR News. Transcript provided by NPR, Copyright NPR.