Which condition is associated with exposure to toxic chemicals or radiation?

• A. Pernicious anemia
• B. Aplastic anemia
• C. Hemolytic anemia
• D. Hemorrhagic anemia

Answer: (B)

Exposure to toxic chemicals or radiation injures the bone marrow’s hematopoietic stem cells, shutting down their ability to produce blood cells. Aplastic anemia is this bone marrow failure state, where the marrow becomes hypocellular and is often replaced by fat, leading to a deficiency of all blood cell lines (pancytopenia). That means lower red cells cause fatigue and pallor, lower white cells raise infection risk, and lower platelets increase bleeding risk. The pattern fits exposures to toxins or radiation, rather than problems that primarily affect RBC destruction (hemolytic), blood loss (hemorrhagic), or vitamin B12–related production issues (pernicious anemia). In managing this, removing the offending exposure and providing supportive care, with therapies like immunosuppression or stem cell transplant when appropriate, are typical approaches.