Radiation Safety Practice Exam

What is the expected outcome at a dose of 650 REM?

1. Full recovery without complications

2. Half of exposed personnel will die even with medical care

3. Symptoms will begin to alleviate

4. No long-term effects are anticipated

The correct answer is: Half of exposed personnel will die even with medical care

The expected outcome at a dose of 650 REM is that half of the exposed personnel will die even with medical care. This level of radiation exposure is significantly above the threshold for acute radiation syndrome (ARS), which typically manifests at doses above 200 REM. At around 650 REM, the overwhelming effects of radiation damage to internal organs and the bone marrow can lead to severe complications. The characteristic symptoms of ARS, such as nausea, vomiting, and fatigue, can begin to appear within hours of exposure, and the damage to the hematopoietic system often results in a decreased ability to produce blood cells. This can lead to serious infections, bleeding, and ultimately, death. The mortality rate at this level of exposure, even with aggressive medical intervention, can be quite high, generally estimated at about 50% lethality within several weeks. In light of this, while other potential outcomes may seem plausible, the specific implications of exposure at 650 REM indicate that a grave prognosis is expected, aligning with the understanding of radiation dose-response relationships in the context of acute radiation exposure.