CDC Lowers the Blood Lead Level That Sparks Action for Kids

Approximately 2.5 percent of 1- to 5-year-olds have a blood lead level above the new reference level, which generally prompts an investigation to find the source

Doctor putting a band aid on a toddler after a blood draw. Photo: iStock

During a child’s first years of life, their blood lead level is routinely checked by pediatricians. Not every child is tested, but doctors generally do blood tests for kids in high-risk ZIP codes, those on Medicaid, and those who have other risk factors, like living in an older building or having a sibling with lead exposure, says Aparna Bole, MD, a pediatrician in Cleveland and chair of the American Academy of Pediatrics’ Council on Environmental Health.

Tests that come in above a certain reference level can trigger investigations into the source of lead, lead to medical follow-up or home remediation, and help identify high-risk communities. On Oct. 28, the Centers for Disease Control and Prevention announced that—for the first time since 2012—the agency was lowering that blood lead reference level, which is used to determine which kids are most exposed to lead. It had been 5 micrograms per deciliter; the new reference level is 3.5 mcg/dL.

In many ways, this doesn’t change anything directly for parents, because any lead exposure should be avoided, Bole says. “There is no safe level of lead,” she says. But the lower limit “could help shine a light on hotspots where lead exposure remains a significant issue.”

Lowering the Blood Lead Level

The blood lead reference value is meant to identify the 2.5 percent of children exposed to the highest levels of lead in the U.S. As overall blood levels of lead have fallen, so has the number.

“Back when I was a resident, the level was 10, before that, the level was 20,” Bole says. The fact that it is now 3.5 shows how changes like removing lead from gasoline and banning lead paint in homes have dramatically reduced children’s exposure to lead in the U.S.

More on Heavy Metals

But that doesn’t mean that the risk that lead poses to children is gone, experts say. While it’s good to see that lead levels have fallen overall, researchers have also realized over time that even low levels of lead exposure can lead to developmental and health problems, says Michael Hansen, PhD, a senior staff scientist at Consumer Reports. And in some populations, including the community that Bole works with in Cleveland, as many as 1 in 4 children still have a blood level higher than 5 mcg/dL, she says.

“Updating the reference value allows CDC, healthcare providers, federal agencies, and health departments to focus on children with the highest exposure,” says Patrick Breysse, PhD, director of the National Center for Environmental Health and the Agency for Toxic Substances and Disease Registry at the CDC. “If a child has a blood lead level of 3.5, parents will now be told that their child is in the highest risk category for the negative effects of lead exposure.”

The updated value should help identify children with a blood lead level between 3.5 and 5 mcg/dL, who previously may have slipped through the cracks, according to Breysse. 

“The key with this is we need to prioritize the kids who are at highest exposure,” says Perry Gottesfeld, executive director of Occupational Knowledge International, a nonprofit organization focused on environmental health. He was also co-chair of the CDC committee that had last revised the blood level in 2012. “This is not only the way to identify individual kids but also the way to identify potential contaminated communities.”

“The Flint incident,” Gottesfeld says, “would have not gotten recognition if we were all looking at 10 micrograms/dL,” because kids there tested between 5 and 10.

But it’s important that this change be accompanied by resources to help make interventions happen, Bole says. In the community that she works with in Cleveland, resources are insufficient for intervention. That means interventions—such as lead abatement in homes and investigations into lead sources—happen only when a child’s blood level is over 10 mcg/dL, even if the level that technically should have triggered that intervention was 5, she says.

While the CDC reference level is meant to be used as a guideline, states and municipalities still set their own limits for when to launch an investigation. That may be dependent on the extent of lead exposure in a community and how many resources are available to deal with it. “States and local governments still need to adopt this,” Gottesfeld says. “Some states have done so, but others have not. In California, we’re still using 10 micrograms/dL.”

Still, if this change from the CDC brings attention that leads to public health changes, such as remediation to remove lead paint from places where kids could be exposed, it could make a difference, Bole says. The most effective interventions are those focused on what’s known as primary prevention—taking steps to remove lead from areas where we already know that the risk of lead exposure is high, according to commentary published in 2019 in the journal Environmental Health. These efforts can protect kids before they are exposed in the first place. 

The lower blood lead level could also increase pressure on other agencies, like the Food and Drug Administration, to take stronger action on heavy metal contamination in food and drink, according to CR’s Hansen. And public health experts have been trying to pressure the Environmental Protection Agency to do more to get lead out of drinking water. Millions of homes get water through service lines that predate the 1986 ban on lead pipes, according to the EPA.

“We need to do more to remove sources of lead from children’s homes and environments,” says Jane Houlihan, research director for Healthy Babies Bright Futures, a nonprofit alliance of scientists and child health advocacy groups. “The federal government needs to move faster to set limits for lead in baby food and to support removal of the estimated 6 to 10 million lead pipes that carry drinking water to American homes.”

What Parents and Caregivers Should Know

Though the situation in the U.S. has improved considerably in recent decades, there are still many heavy metal hazards in the environment. Lead has been found in soil, some toys, ceramics, and water lines and fixtures. It’s also frequently found in paint inside homes built before 1978, when lead paint was banned. Certain industries and jobs still expose people to lead, aviation gas can contaminate soil and air near airports with lead, and lead deposits in soil still persist from leaded gasoline and exterior lead-based paint that predates the ban, especially in urban areas.

Despite that ubiquity, it’s important for families to take steps to protect kids, Breysse says. “Even low levels of lead in blood have been shown to affect learning, ability to pay attention, and academic achievement,” he says.

Many of these things require intervention beyond what parents and caregivers can do on their own, but states often have programs that can help, Bole says. Check with your local department of health or ask your pediatrician if you have questions.

Parents can also talk to their pediatrician about getting a blood lead test, because most children with lead in their blood don’t show obvious symptoms, according to Breysse.

It’s worth having older homes inspected for lead, especially before beginning a remodel or renovation that can create lead dust, according to the CDC. The agency recommends covering up chipping or peeling paint with contact paper or duct tape and cleaning frequently around windows, floors, and play areas. Wet mopping and vacuuming regularly can also help clean up lead dust, according to Bole. 

Always use cold water for cooking and run water for 45 seconds before using it to get drinking water or make baby formula, according to the EPA. You should remove and rinse the small screen on your faucet—known as an aerator—every few months. If you are concerned about lead in your water system, get a water filter that’s NSF/ANSI 53 certified. Some water utilities offer free lead testing, or you can get a test sold at cost from Healthy Babies Bright Futures.

Diet can also make a difference. CR experts recommend avoiding fruit juice, which sometimes contains heavy metals, including lead. And eating a healthy diet overall can help, according to Bole.

It’s important to make sure kids are getting enough nutrients, including vitamin C, calcium, and iron, she says. Nutrition affects brain development, and iron-deficient children are more likely to absorb lead. The general advice pediatricians give for encouraging healthy brain development, like reading to kids and sending them to preschool, can help brains develop resilience and counter the effects of potential exposure, she says.

Head shot image of CRO Health editor Kevin Loria

Kevin Loria

I'm a science journalist who writes about health for Consumer Reports. I'm interested in finding the ways that people can transform their health for the better and in calling out the systems, companies, and policies that expose patients to unnecessary harm. As a dad, I spend most of my free time trying to keep up with a toddler, but I also enjoy exploring the outdoors whenever possible. Follow me on Twitter (@kevloria).