Lead exposure in children primarily affects which body system?

• A. Digestive system
• B. Nervous system
• C. Immune system
• D. Skeletal system

Answer: (B)

Lead acts as a potent neurotoxin in children. The developing brain is especially vulnerable because lead can cross the still-maturing blood-brain barrier and disrupt processes critical for brain growth, such as calcium-dependent signaling, neurotransmitter release, and the formation and myelination of connections. This interference manifests as cognitive delays, lower IQ, attention problems, and behavioral or learning difficulties. Other body systems can be affected—like the digestive system or blood production—but these effects are secondary to the impact on the nervous system. So, the nervous system is the body system most affected by lead exposure in children.