KEY POINTS

  • The researchers checked for lead in the blood of over one million U.S. children
  • There is no known "safe" blood lead concentration: WHO
  • Kids get exposed to lead via contact with old lead paint, dust or soil in buildings and houses

About half of children in the U.S. had detectable levels of lead in their blood, a team of researchers found. This comes despite the progress that the U.S. has made in reducing children's exposure to the toxic metal.

To determine individual and community level factors linked to "detectable and elevated" blood lead levels (BLL) in children, the researchers of a new study, published Monday in the journal JAMA Pediatrics, analyzed the blood lead test results of 1,141,441 children younger than six years old.

The testing occurred from Oct. 1, 2018, to Feb. 29, 2020, with the children living in all 50 states and the District of Columbia. Researchers looked at individual factors such as sex, age and insurance type, while the community level categories were poverty, pre-1950s housing, race and ethnicity and geographical region.

The researchers found that 576,092 or "more than half" of the children that they tested had detectable BLLs. Although most had "relatively smaller" amounts, about 2% actually had levels that were considered to be "high," Bloomberg noted.

Some of the common ways that children can get exposed to lead are via contact with old lead paint, dust or soil in buildings and houses, the Centers for Disease Control and Prevention (CDC) noted.

"The proportion of children with detectable and elevated BLLs increased significantly for progressive pre-1950s housing and poverty quintiles," the researchers wrote.

"Children residing in zip codes with predominantly Black non-Hispanic and non-Latinx populations had higher odds of detectable BLLs (AOR, 1.13 [95% CI, 1.11-1.15]) but lower odds for elevated BLL (AOR, 0.83 [95% CI, 0.80-0.88])," they added.

According to the researchers, the results of the study show that there are still persisting individual and community level disparities "despite progress in reducing pediatric lead exposure."

"The broad picture is: kids have lead in the U.S. For lead, there's no too low. We want zero," Morri Markowitz of the lead poisoning prevention and treatment program at Children's Hospital at Montefiore, said as per Bloomberg. Markowitz was not involved in the study.

So far, "no safe level of exposure to lead has been identified," the researchers wrote. Young children are particularly vulnerable to lead poisoning as they tend to absorb four to five times more ingested lead as adults. Further, their "innate curiosity" and "age-appropriate hand-to-mouth" behavior may also contribute to the risk of putting lead-contaminated or coated objects in their mouths.

"At lower levels of exposure that cause no obvious symptoms lead is now known to produce a spectrum of injury across multiple body systems," the World Health Organization noted. "In particular lead can affect children's brain development resulting in reduced intelligence quotient (IQ), behavioral changes such as reduced attention span and increased antisocial behavior, and reduced educational attainment. Lead exposure also causes anemia, hypertension, renal impairment, immunotoxicity and toxicity to the reproductive organs."

Childhood lead poisoning is "100% preventable," the CDC said. What's important is to prevent children from coming in contact with common sources of lead such as lead paint and dust, imported candies, toys and cosmetics and drinking water contaminated by lead from lead pipes.

Children with Pet Dog Representation. Photo: Pixabay