Biological Effects of Radiation Flashcards

Which of the following is considered a stochastic effect of radiation exposure?

Answer: Cancer

Stochastic effects are those for which the probability of occurrence increases with dose, but the severity is independent of the dose. Cancer is the primary stochastic effect of concern in radiation protection. The other options are deterministic (or tissue reaction) effects, which have a dose threshold and whose severity increases with dose.

According to the Law of Bergonié and Tribondeau, which of the following cells would be MOST radiosensitive?

Answer: Rapidly dividing, undifferentiated cells

The Law of Bergonié and Tribondeau states that radiosensitivity is directly proportional to the rate of cell division (mitotic activity) and inversely proportional to the degree of cell differentiation. Therefore, cells that are rapidly dividing and are not specialized (undifferentiated), such as stem cells in bone marrow or the gastrointestinal lining, are the most sensitive to radiation.

An industrial radiographer receives a high dose of radiation over a very short period due to an equipment malfunction. The immediate effects they might experience, such as nausea, are classified as what type of effects?

Answer: Acute effects

Acute effects are health effects that appear within hours, days, or weeks following a high dose of radiation delivered over a short time. Chronic effects result from exposure to smaller doses over a long period. Genetic effects are passed on to future generations, and teratogenic effects are those that affect an embryo or fetus.

Which of the following is an example of a somatic effect of radiation exposure?

Answer: Cataract formation in the exposed individual

Somatic effects are those that affect the body of the exposed individual during their lifetime. Cataracts, skin burns, and cancer are all examples of somatic effects. Genetic (or heritable) effects are those that occur in the reproductive cells and can be passed on to offspring.

Deterministic effects of radiation, such as skin erythema or sterility, are characterized by which of the following?

Answer: A threshold dose below which the effect is not observed

Deterministic effects (also called tissue reactions) are characterized by a threshold dose; the effect will not occur unless a certain minimum dose is received. Once that threshold is exceeded, the severity of the effect increases with the dose. This is in contrast to stochastic effects, which have no threshold.

A worker is exposed to a significant whole-body dose of radiation. After an initial period of nausea and fatigue, they feel relatively well for several days. This symptom-free period is known as the:

Answer: Latent stage

Acute Radiation Syndrome (ARS) typically progresses through four stages. The initial symptoms occur in the prodromal stage. This is followed by the latent stage, a period where the individual appears and feels healthy, which can last for hours or weeks. The manifest illness stage is when severe symptoms return, and the final stage is either recovery or death.