The effects of lead exposure depend on a child’s age at the time of exposure, the dose and duration, and other health or environmental factors.

Children may not show signs of lead toxicity until years later—often when academic or behavioral demands increase in school. Even low levels of lead can harm brain development and cognitive function, but symptoms may be subtle and hard to attribute to lead alone.

Acute exposure (a large dose over a short time) can cause immediate symptoms like irritability, headaches, fatigue, stomach pain, or seizures—typically classified as lead poisoning. Chronic low-level exposure, however, may not cause obvious signs but can lead to learning difficulties, attention problems, or delays in language and motor skills. These effects may only become apparent with age or through developmental testing and/or IQ testing.

Historically, products like leaded paint and gasoline caused widespread exposure, but blood lead levels declined significantly after regulations took effect in the 1990s. However, in countries with weaker standards, lead exposure remains a concern.