Chapter 9 Radbio

Line 1 on the response curves represents

• linear non-threshold curve

• linear threshold curve

• nonlinear threshold curve

• sigmoid threshold curve

 

Line 2 on the response curves represents;

• non-linear threshold curve

• linear threshold curve

• linear non- threshold curve

• sigmoid threshold curve

 

Line 3 on the response curves represents

• nonlinear threshold curve

• linear threshold curve

• linear non-threshold curve

• sigmoid threshold curve

After the Chernobyl disaster in 1986, an attempt was made to prevent thyroid cancer in Poland and some other countries, resulting from the accidental overdose of iodine-131. _______________ was administered to children as a substitute to block the gland’s uptake of iodine-131.

• Sodium chloride

• Potassium bromide

• Sodium bicarbonate

• Potassium iodide

Among the atomic bomb survivors, the number of leukemia victims has _______________ since the late 1940s and early 1950s. However, the occurrence rates of other radiation-induced malignancies have continued to ___________since the late 1950s and early 1960s.

• slowly declined; escalate

• increased rapidly; decrease

• increased slowly; decrease

• rapidly declined; decrease

Currently, evidence of radiation-induced hereditary effects has not been observed in persons employed in diagnostic imaging or in persons undergoing radiologic examinations. Even with this information, it is still recommended that

1. gonadal shielding be effectively used.

2. all radiation exposure be maintained as low as reasonably achievable (ALARA).

3. alternative procedures be substituted for x-ray procedures whenever diagnostic information must be obtained.

• 1 and 3

• 2 only

• 1,2 and 3

• 1 and 2

During the 1950s and 1960s, the Navajo people of Arizona and New Mexico who mined uranium for fuel for nuclear weapons and power plants developed lung cancer years after their exposure. This provides an example of which of the following?

• Late stochastic effects

• Early tissue reactions

• Late tissue reactions

• Late genetic effects

Genetic effects from exposure to ionizing radiation occur as a result of radiation-induced damage to the DNA molecule in which of the following?

1. Sperm of a man

2. Ova of a woman

3. Somatic cells of men and women

• 2 and 3

• 1 and 3

• 1 and 2

• 3 only

In which of the following human populations is the risk for causing a radiation-induced cancer not directly measurable?

1. All patients in diagnostic radiology subjected to a radiation dose below 0.1 Sv

2. Chernobyl radiation accident victims living in contaminated villages

3. Atomic bomb survivors

• 1 only

• 2 only

• 3 only

• 1 and 2

The term linear nonthreshold relationship implies that the biologic response to ionizing radiation is

• directly proportional to the dose all the way down to levels approaching zero.

• inversely proportional to the dose all the way down to levels approaching zero.

• directly proportional to the square of the dose all the way down to levels approaching zero.

• inversely proportional to the square of the dose all the way down to levels approaching zero.