Radiation Injury MCQ Quiz | Poisonings & Environmental

1. Which unit is used to measure the absorbed dose of ionizing radiation?

• Sievert (Sv)
• Gray (Gy)
• Becquerel (Bq)
• Curie (Ci)

2. The Law of Bergonie and Tribondeau states that radiosensitivity is directly proportional to:

• Cellular differentiation
• Cellular age
• Mitotic activity
• Cell size

3. Which of the following is a classic example of a stochastic effect of radiation?

• Carcinogenesis
• Skin erythema
• Cataract formation
• Acute Radiation Syndrome

4. The hematopoietic syndrome of Acute Radiation Syndrome (ARS) is typically seen at whole-body doses of:

• 0.1 – 0.5 Gy
• 1 – 6 Gy
• 8 – 10 Gy
• > 20 Gy

5. What is the most useful early biological indicator for estimating the dose of radiation exposure?

• Platelet count
• Reticulocyte count
• Absolute lymphocyte count
• Erythrocyte sedimentation rate

6. Internal contamination with Iodine-131 specifically targets which organ?

• Bone marrow
• Lungs
• Thyroid gland
• Liver

7. The symptom-free period between the prodromal and manifest illness phases of ARS is known as the:

• Latent phase
• Recovery phase
• Subclinical phase
• Interphase

8. Which type of ionizing radiation has the highest linear energy transfer (LET) and is most damaging when inside the body?

• Gamma rays
• Beta particles
• Alpha particles
• X-rays

9. The primary cause of death in the Gastrointestinal (GI) syndrome of ARS is:

• Hemorrhage due to thrombocytopenia
• Cerebral edema
• Respiratory failure
• Dehydration, electrolyte imbalance, and sepsis

10. Strontium-90 is a hazardous radionuclide because it chemically mimics which element and deposits in the bone?

• Potassium
• Calcium
• Sodium
• Magnesium

11. A dose of >20 Gy to the whole body will most likely result in which ARS syndrome?

• Hematopoietic
• Gastrointestinal
• Neurovascular
• Cutaneous

12. Which of the following is the most radiosensitive tissue in the human body?

• Nerve tissue
• Muscle tissue
• Lymphoid tissue
• Bone tissue

13. The administration of potassium iodide (KI) is a protective measure against the uptake of:

• Strontium-90
• Cesium-137
• Plutonium-239
• Iodine-131

14. What does the term LD50/60 represent in the context of radiation exposure?

• The dose at which 50% of cells die within 60 minutes.
• The dose that is lethal to 50% of an exposed population within 60 days.
• The dose that causes a 50% reduction in lymphocytes in 60 hours.
• The dose required to sterilize 50% of the population in 60 days.

15. A patient presents with nausea, vomiting, and fatigue within 2 hours of a known radiation exposure. These symptoms are characteristic of which phase of ARS?

• Latent phase
• Prodromal phase
• Manifest illness phase
• Recovery phase

16. The chelating agent DTPA (Diethylenetriamine pentaacetic acid) is used to treat internal contamination with:

• Iodine-131
• Cesium-137
• Transuranic elements like Plutonium
• Strontium-90

17. A deterministic effect of radiation is characterized by:

• A threshold dose below which the effect does not occur.
• The probability of the effect increasing with dose, but not its severity.
• An all-or-none response regardless of the dose.
• Effects that appear many years after exposure.

18. Cesium-137 poses a significant health risk because it is chemically similar to potassium and:

• Concentrates exclusively in the thyroid.
• Is deposited on the bone surface.
• Distributes widely throughout soft tissues.
• Is not absorbed by the body.

19. Which drug is known as a radioprotector, used to reduce the toxic effects of radiation therapy in certain tissues?

• Filgrastim (G-CSF)
• Amifostine
• Potassium Iodide
• Prussian Blue

20. In the Neurovascular syndrome of ARS, the rapid onset of symptoms is primarily due to damage to the:

• Bone marrow stem cells
• Crypt cells of the intestine
• Microvasculature of the brain
• Hepatocytes

21. The main cause of death in the hematopoietic syndrome of ARS is:

• Fluid and electrolyte loss
• Infection and hemorrhage
• Neurological collapse
• Pulmonary fibrosis

22. The earliest sign of Cutaneous Radiation Injury (CRI) is typically:

• Necrosis
• Epilation (hair loss)
• Erythema (reddening of the skin)
• Ulceration

23. The “walking ghost” phase is an alternative name for which period in Acute Radiation Syndrome?

• Prodromal phase

• Latent phase

• Manifest illness phase

• Recovery phase

24. Which of the following is considered the LEAST radiosensitive tissue?

• Intestinal crypt cells

• Germinal cells of the ovary

• Hematopoietic stem cells

• Mature nerve cells

25. The unit Sievert (Sv) is used to quantify equivalent dose, which accounts for:

• The total energy deposited in tissue.

• The rate at which radiation is delivered.

• The biological effectiveness of different types of radiation.

• The volume of tissue irradiated.