Lead and Mechanisms

Lead Exposure Effects

Damage to brain and nervous system development, slowed growth, motor development deficits, learning and behavioral issues, hearing and speech deficits.

Sources of Lead

Mining and manufacturing of ceramics and glassware.

Effects of Lead at Low Exposure

Adverse health effects in children at less than 5 µg/dL of blood lead levels can include developmental delays, lower IQ, and increased behavioral problems.

Blood Brain Barrier (BBB)

Formed by endothelial cells lining the cerebral microvasculature, it limits the passage of pathogens or toxins capable of disturbing neural function.

Lead's Impact on BBB

Lead increases the permeability of the BBB by disrupting protein kinase C, leading to leaky tight junctions and potential edema and encephalopathy.

Astrocytes

Support the integrity of the BBB and neurons; they regulate the composition of interstitial fluid and are targeted by lead.

Caspases

Proteins that play essential roles in apoptosis; initiator caspases include 8, 9, and 10, while effector caspases include 1-7 and 11-13.

Neurotoxicity Mechanisms of Lead

Includes apoptosis, excitotoxicity, protein malfunction, lipid peroxidation, DNA oxidation, and impaired synaptic function.

Motor Development Delays

Delayed motor milestones and deficits in both fine and gross motor coordination.

Verbal Communication Issues due to Lead

Includes hearing deficits, poor speech articulation, delayed language, and poor language understanding.

Social Behavior Effects of Lead

Can result in anti-social behavior, delinquency, difficulty controlling aggression, and impulsivity.

Dendritic Spines

Specialized for synaptic transmission, lead decreases the number of mushroom spines which are associated with memory.