What is the LD50/30 for adult humans?

What is the LD50/30 for adult humans?

• A. 1 Gy
• B. 2.5 Gy
• C. 3 Gy
• D. 3 to 4 Gy

Answer: (D)

LD50/30 is the radiation dose that would kill 50% of exposed adults within 30 days. For humans, this value isn’t a single fixed number because survival depends on factors like age, health, and whether supportive medical care is available. In typical casualty scenarios with medical support, about half of adults exposed to roughly 3 to 4 Gy would die within a month due to bone marrow (hematopoietic) failure. Doses around 1–2.5 Gy have much lower mortality, while higher doses push toward death from more severe syndromes. Since 3–4 Gy spans the range where mortality reaches ~50%, that interval best represents LD50/30 for adult humans.

LD50/30 is the radiation dose that would kill 50% of exposed adults within 30 days. For humans, this value isn’t a single fixed number because survival depends on factors like age, health, and whether supportive medical care is available. In typical casualty scenarios with medical support, about half of adults exposed to roughly 3 to 4 Gy would die within a month due to bone marrow (hematopoietic) failure. Doses around 1–2.5 Gy have much lower mortality, while higher doses push toward death from more severe syndromes. Since 3–4 Gy spans the range where mortality reaches ~50%, that interval best represents LD50/30 for adult humans.