The most likely effect at 50 REM that is entirely reversible is which of the following?

The most likely effect at 50 REM that is entirely reversible is which of the following?

• A. Hair loss
• B. Severe GI symptoms
• C. Neurological deficits
• D. Minor fluctuations in blood count

Answer: (D)

At low whole-body radiation doses, the hematopoietic system is the most sensitive and the effect you’d expect is a transient change in blood counts. The bone marrow can show a brief dip in circulating white cells and platelets after exposure, but this is typically reversible within days to weeks with no lasting harm. Fifty rem (about 0.5 Gy for gamma/X-ray quality) is well below the thresholds for deterministic effects like hair loss, GI symptoms, or neurological damage, which occur at higher doses. Hair loss usually requires several Gy to a large area; GI symptoms follow at higher exposures; neurological deficits appear only at very high doses. So the entirely reversible outcome at this dose is minor fluctuations in blood count.

At low whole-body radiation doses, the hematopoietic system is the most sensitive and the effect you’d expect is a transient change in blood counts. The bone marrow can show a brief dip in circulating white cells and platelets after exposure, but this is typically reversible within days to weeks with no lasting harm. Fifty rem (about 0.5 Gy for gamma/X-ray quality) is well below the thresholds for deterministic effects like hair loss, GI symptoms, or neurological damage, which occur at higher doses. Hair loss usually requires several Gy to a large area; GI symptoms follow at higher exposures; neurological deficits appear only at very high doses. So the entirely reversible outcome at this dose is minor fluctuations in blood count.