Axios Des Moines: An estimated 76% of Iowa children under 6 years old had lead detected in their blood, according to a newly released study conducted between 2018 and 2020. It's among the highest proportions in the nation, behind Nebraska (83%), Missouri (82%) and Michigan (78%). The national rate was about 51%. 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.