Which group is more sensitive to potential adverse effects of radiation?

• A. An unborn child
• B. Adults
• C. Children
• D. Neonates

Answer: (A)

The main idea is that radiosensitivity varies with developmental stage and tissue maturity. The unborn child is the most sensitive because during fetal development cells are dividing rapidly and organs are forming. This high cellular proliferation and differentiation mean DNA damage from ionizing radiation can more easily disrupt development, leading to congenital anomalies, growth retardation, neurodevelopmental effects, and a greater lifetime cancer risk. In contrast, adults have more mature tissues, slower cell turnover, and better DNA repair capacity, making them less vulnerable. Neonates and children are more sensitive than adults but are still less vulnerable than a developing fetus. So the unborn child is the most sensitive group to potential adverse radiation effects.