How does lead exposure damage children's brains at the cellular level?

What's actually in it

Lead enters homes through old paint (pre-1978 homes), contaminated soil, old plumbing fixtures and pipes, and some imported products. Children absorb 50% of ingested lead, compared to 10% in adults. Lead goes directly to the brain.

There is no safe blood lead level in children. The CDC's reference level of 3.5 mcg/dL isn't a safe level, it's a threshold for clinical action. Harm starts below it.

What the research says

A 2026 review in Neurotoxicology detailed the mechanisms by which lead damages children's brains at the cellular and molecular level. Lead displaces calcium and zinc from synaptic signaling proteins. Calcium is the messenger that controls whether neurons fire. Lead hijacks calcium channels and receptors, disrupting the normal electrical signaling that underlies learning and memory.

Lead also disrupts NMDA receptors, the glutamate receptors central to synaptic plasticity and long-term memory formation. Even at low levels, lead reduces the brain's ability to strengthen synaptic connections in response to learning.

These effects translate directly into the real-world outcomes seen in population studies: lower IQ, impaired executive function, attention deficits, and behavioral problems. The damage accumulates. Even brief periods of elevated lead exposure in early childhood leave lasting marks on brain architecture.