A radiation exposure dose delivered within a period greater than 24 hours duration is known as?

• A. A chronic dose
• B. An acute dose
• C. A transient dose
• D. A temporary dose

Answer: (A)

Duration of exposure determines how a radiation dose is described. If the dose is delivered over a period longer than 24 hours, it is referred to as a chronic (protracted) exposure. Chronic exposure typically involves a lower dose rate spread out over time, accumulating to a total dose and carrying risks that unfold with time. In contrast, an acute dose is delivered in a short time frame—minutes to hours—with a higher dose rate and the potential for immediate effects. Terms like transient or temporary aren’t standard classifications for radiation exposure duration, so the description that fits a period exceeding 24 hours is chronic exposure.