Radiation Biology and Health Effects Flashcards
6 cards from real RSO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Radiation Biology and Health Effects flashcards as text
What term describes the ability of ionizing radiation to cause biological damage by directly breaking chemical bonds in DNA?
Answer: Direct action
Direct action occurs when ionizing radiation interacts directly with critical biomolecules such as DNA, breaking chemical bonds without involving intermediate water radicals.
Which type of radiation has the highest relative biological effectiveness (RBE) for causing biological damage?
Answer: Alpha particles
Alpha particles have the highest RBE because their dense ionization tracks cause clustered DNA damage that is difficult for cells to repair.
The linear no-threshold (LNT) model assumes that radiation risk is:
Answer: Proportional to dose at all levels with no safe threshold
The LNT model postulates that any dose of radiation, no matter how small, carries a proportional cancer risk with no completely safe threshold.
Acute radiation syndrome (ARS) typically requires a whole-body dose of at least:
Answer: 1 Sv
ARS generally requires a whole-body absorbed dose of approximately 1 Sv (100 rem) delivered over a short period to produce clinically significant symptoms.
Which organ system is most sensitive to radiation-induced damage in adults, making it the primary determinant of survival after high acute doses?
Answer: Hematopoietic (bone marrow) system
The hematopoietic system is most radiosensitive in adults; bone marrow suppression leading to infection and hemorrhage is the dominant cause of death at moderate acute doses.
Stochastic radiation effects such as cancer are characterized by:
Answer: Probability increasing with dose but severity independent of dose
Stochastic effects have a probability of occurrence that increases with dose, but if the effect occurs, its severity does not depend on the dose received.