A study involving more than 1.1 million U.S. children found 50.5 percent have detectable lead levels in their blood, according to findings published Sept. 27 in JAMA Pediatrics.
Researchers combined data from Quest Diagnostics lead testing and the U.S. Census to evaluate lead exposure among 1,141,441 children under 6 years old across all 50 states. They analyzed blood tests performed between October 2018 through February 2020.
While previous research has focused on elevated blood lead levels, little has focused on exposure levels that are lower but still detectable — one of the factors prompting the study since no level of lead exposure is considered safe, researchers said.
Four findings:
1. About 50.5 percent of children had detectable lead levels in their blood, while 1.9 percent (21,172 children) had elevated levels, which are known to affect cognitive development.
2. Adjusted analyses found those with public insurance were more likely to have detectable or elevated lead levels in their blood, as well as children living in low-income neighborhoods or communities with houses built before the 1950s.
3. Children living in ZIP codes with predominantly Black or Hispanic populations had higher odds of detectable lead levels in their blood, but lower odds for elevated levels.
4. Nebraska had the highest proportion of children with detectable lead levels in their blood at 83 percent.
"To our knowledge, this is one of the first comprehensive national analyses investigating the association of lead exposure with individual- and community-level factors," researchers said.
"There has been significant progress in reducing lead exposure throughout the country; this study demonstrates, however, that there are still substantial individual- and community-level disparities that have important implications for addressing childhood lead exposure."