What is the principle of distance in radiation protection?

The principle of distance in radiation protection is based on the concept that increasing the distance from a radiation source significantly reduces exposure to radiation. This principle is rooted in the inverse square law, which states that the intensity of radiation decreases with the square of the distance from the source. By doubling the distance from a source, for example, the radiation exposure is reduced to one-fourth. This principle is crucial for protecting individuals working with or around radioactive materials, as it allows for a measurable reduction in risk of radiation exposure simply by maximizing the distance from the source. This strategic approach helps maintain safety standards in environments where radiation is present.

While the other options involve valid radiation safety practices—such as using barriers, reducing time spent near radiation, and minimizing the use of radioactive materials—none encapsulate the specific principle associated with distance as effectively as the correct choice does. The concept of distance stands out as a fundamental practice in minimizing radiation exposure.