Lead is a major environmental health hazard for young children. Childhood exposure to lead contributes to learning problems, including reduced intelligence quotient (IQ) and reduced academic achievement, as well as behavioral problems.¹ The Centers for Disease Control and Prevention (CDC) lowered the blood lead reference level from 5 micrograms lead per deciliter of blood (µg/dL) to 3.5 µg/dL in 2021 to identify children with elevated blood lead levels.² A blood lead level above CDC's reference value is defined as "elevated" for purposes of identifying children for follow-up activities, such as environmental investigations and ongoing monitoring,³ but no level of childhood lead exposure can be considered safe,⁴ and adverse health effects can occur at much lower concentrations.¹ Lead exposure has declined since the 1970s, due largely to the removal of lead from gasoline and paint. Children ages 1–5—the focus of this indicator—are particularly vulnerable because they frequently engage in hand-to-mouth behavior.

Indicator PHY4.A Percentage of children ages 1–5 with blood lead levels at or above 3.5 µg/dL, selected years 1988–1994 through 2017–March 2020

Indicator PHY4.B Percentage of children ages 1–5 with blood lead levels at or above 3.5 µg/dL by race and Hispanic origin and poverty status, 2017–March 2020

• In 2017–March 2020, the percentage of children ages 1–5 with elevated blood lead levels (at or above 3.5 µg/dL) was 1.4%. This percentage was 18.5% in 1999–2002 and 43.0% in 1988–1994.
• In 2017–March 2020, 2.8% of Black, non-Hispanic children, 1.5% of Mexican American children, and 1.3% of White, non-Hispanic children had blood lead levels at or above 3.5 µg/dL. These differences were not statistically significant.
• In 2017–March 2020, 1.7% of children living in poverty had blood lead levels at or above 3.5 µg/dL. This percentage was 29.6% in 1999–2004.

 PHY4.A HTML Table | PHY4.B HTML Table