What is the ALARA principle in radiation safety?

• A. As Low As Readily Acceptable; ignore time and distance.
• B. As Low As Reasonably Achievable; minimize radiation exposure through limiting time, increasing distance, and using shielding.
• C. All Levels Are Readily Avoidable; ignore shielding.
• D. As Large As Reasonably Added; maximize exposure.

Answer: (B)

ALARA stands for As Low As Reasonably Achievable. It’s a safety approach in radiation protection that aims to keep any exposure as low as practicable by applying practical controls and decisions that consider feasibility, cost, and benefits. The best answer captures both the purpose and the actions: minimize radiation exposure through limiting time spent near the source, increasing distance from the source, and using shielding to block or reduce the dose.

In practice, this means active strategies like reducing how long a worker is exposed during a procedure, staying as far away as safely possible from the radiation source, and wearing or installing shielding such as lead aprons, barriers, or containment to reduce dose. ALARA accepts that some exposure may be unavoidable, but pushes for continuous improvement to keep it as low as reasonably achievable.

The other statements miss essential points: the first uses an incorrect acronym and suggests ignoring time and distance; the third implies all levels are avoidable and ignores shielding; the fourth distorts the concept entirely by suggesting increasing exposure.