Which population group is most radiosensitive?

Which population group is most radiosensitive?

• A. One-year-old child
• B. Twenty-year-old young adult
• C. Fifty-year-old adult
• D. All are equally radiosensitive

Answer: (A)

Radiosensitivity is highest in cells that are actively dividing and in developing tissues. A one-year-old child has many cells undergoing rapid growth and division, including in bone marrow and the lining of the gut, so radiation can cause more damage to those rapidly dividing cells and lead to more pronounced effects. As people age, cell turnover slows and tissues become more mature, making them less sensitive to radiation. Therefore, among the given groups, the one-year-old child is the most radiosensitive. The twenty-year-old and fifty-year-old have lower radiosensitivity due to slower cell division and more mature tissues.

Radiosensitivity is highest in cells that are actively dividing and in developing tissues. A one-year-old child has many cells undergoing rapid growth and division, including in bone marrow and the lining of the gut, so radiation can cause more damage to those rapidly dividing cells and lead to more pronounced effects. As people age, cell turnover slows and tissues become more mature, making them less sensitive to radiation. Therefore, among the given groups, the one-year-old child is the most radiosensitive. The twenty-year-old and fifty-year-old have lower radiosensitivity due to slower cell division and more mature tissues.