An estimated 76% of Iowa children under six years old had lead detected in their blood, according to a newly released study conducted between 2018 and 2020.

• It's among the highest proportion in the nation, behind Nebraska (83%), Missouri (82%) and Michigan (78%). The national rate was about 51%.

Why it matters: There's no blood lead level that has been identified as safe in children, according to the CDC. Even low-level exposures can negatively affect IQ, behavior and academic achievement.

• Lead poisoning is considered the most preventable environmental disease of young children, according to the Iowa Department of Public Health (IDPH).

Driving the news: The study, published last month by JAMA Pediatrics, is believed to be the first national analysis into the association of lead exposure with individual- and community-level factors, Axios' Marisa Fernandez writes.

• Researchers analyzed blood lead tests that Quest Diagnostics administered to 1.14 million U.S. children between October 2018 and February 2020.

By the numbers: The study shows 3.6% of Iowa children had blood lead levels of five micrograms per deciliter or greater, a standard the CDC uses to help identify elevated cases.

• According to the IDPH, nearly 2,240 children under age six had elevated lead levels in 2019.

Between the lines: Children from predominantly Black or Hispanic ZIP codes were disproportionately affected, compared to those in predominantly white ZIP codes.

• Kids from areas with pre-1950s housing had significantly higher levels.

What they're doing: The CDC recommends states adopt statewide screening plans.

• Iowa has been requiring blood lead testing for kindergarteners since 2008. It's considered one of the most comprehensive state requirements in the nation, according to the Network for Public Health Law.

But despite Iowa law, more than 23% of kids entering kindergarten last year had no record of a blood lead test, according to the IDPH.

• Children living in rural areas had the highest likelihood of not having been tested.

Full story: Majority of Iowa children under age 6 have lead in their blood