1. Which of the following statements is false?

a. By "prodromal radiation syndrome" are denoted the symptoms that appear soon after a high-intensity exposure to radiation. These symptoms last for a limited period of time.

b. By "early radiation lethality" is meant death occuring within, at most, a few weeks after a high-intensity exposure to radiation.

c. Early radiation lethality is subdivided into three distinct modes of death: the cerebrovascular syndrome, the gastrointestinal syndrome and the hematopoietic syndrome.

d. The mode of early radiation lethality is not related to the dose.

2. Total-body doses in excess of 100 Gy (gamma rays), which cause death within 24 to 48 hours after exposure, are connected to:

a. the cerebrovascular syndrome.

b. the gastrointestinal syndrome.

c. the hematopoietic syndrome.

3. The gastrointestinal syndrome is induced by a total-body absorbed dose of:

a. more than 100 Gy of gamma rays.

b. more than 10 Gy of gamma rays.

c. 3-8 Gy of gamma rays.

4. Bone-marrow death occurs:

a. 24 hours after irradiation.

b. a few days after irradiation.

c. several weeks after irradiation.

5. Which of the following symptoms is characteristic of the cerebrovascular syndrome?

a. Nausea.

b. Vomiting.

c. Disorientation.

d. Diarrhea.

6. By LD_50/30 is denoted:

a. The dose required to induce death in 50% of a given population by 30 days after irradiation.

b. The dose required to induce sublethal damage in 50% of a given population by irradiation with a beam which has a LET value of 30.

c. The dose required to induce death of 30% - 50% of the population.

7. Which of the following statements regarding the prodromal syndrome is false?

a. The prodromal syndrome is caused by the LD₅₀ dose.

b. The main symptoms of the syndrome are nausea and vomiting.

c. The syndrome is followed by a symptom-free period, known as the latent period.

d. No significant biological events take place during the latent period.

8. The LD_50/60 dose for humans is approximately equal to:

a. 1 Gy.

b. 4 Gy.

c. 10 Gy.

d. 60 Gy.

9. Which of the following statements regarding the treatment of radiation accident victims is false?

a. At doses less than 4 to 5 Gy, the patient is only treated in response to specific symptoms.

b. At doses 5-8 Gy, infection, bleeding and physical trauma are to be avoided during the period in which the circulating blood elements have a low concentration.

c. At doses 8-10 Gy, a bone-marrow transplant can be administrated.

d. At doses above 10 Gy, a bone-marrow transplant must always be administrated.

10. The LD₅₀ dose (4 Gy) can be doubled by careful nursing and an antibiotic screen.

a. True.

b. False.