A single whole body dose of how many rads could result in death –
**Core Concept**
Acute radiation syndrome (ARS) is a condition that occurs when the body is exposed to a high dose of ionizing radiation, causing damage to the bone marrow, gastrointestinal system, and central nervous system. The severity of ARS depends on the dose and rate of radiation exposure.
**Why the Correct Answer is Right**
A dose of 10-20 Gy (1000-2000 rads) can cause severe damage to the bone marrow, leading to a significant decrease in white blood cells and platelets, increasing the risk of infection and bleeding. The gastrointestinal system is also affected, causing nausea, vomiting, and diarrhea, which can lead to dehydration and electrolyte imbalances. At this dose, the central nervous system may also be affected, causing confusion, seizures, and loss of consciousness. The exact dose at which death occurs can vary depending on individual factors, but 10-20 Gy is a commonly cited range.
**Why Each Wrong Option is Incorrect**
**Option A:** A dose of 1 Gy (100 rads) is unlikely to cause death, as it is a relatively low dose and the body's natural repair mechanisms can mitigate the damage.
**Option B:** A dose of 50 Gy (5000 rads) is extremely high and would likely cause immediate death, as it would cause severe damage to the entire body, including the central nervous system.
**Option C:** A dose of 5 Gy (500 rads) is a moderate dose, but it would not typically cause death, as the body's repair mechanisms can still mitigate the damage.
**Clinical Pearl / High-Yield Fact**
The LD50/30 (lethal dose for 50% of the population within 30 days) for radiation exposure is approximately 3.5 Gy (350 rads), which is a commonly cited benchmark for the severity of radiation exposure.
**Correct Answer: C. 5 Gy (500 rads)**