Lead exposure is associated with radiographic changes in bones known as metaphyseal endplate changes. Which metal is responsible?

• A. Arsenic
• B. Lead
• C. Mercury
• D. Cyanide

Answer: (B)

Lead exposure disrupts mineralization in the growing skeleton, producing a dense transverse band across the metaphyses on X-ray called a metaphyseal endplate change (lead line). This radiographic sign appears in children because lead accumulates in the metaphyseal region during rapid growth and interferes with endochondral ossification, creating a clearly visible, sclerotic line at the zone of provisional calcification. The other metals listed do not produce this specific metaphyseal line on radiographs, making lead the correct association. Clinically, lead poisoning also features other clues such as a Burtonian line on the gums and anemia, reinforcing the link to lead exposure.