Which protective measure involves using distances that minimize exposure?

The protective measure that involves distances to minimize exposure is increasing distance. This is based on the principle of radiation protection known as the inverse square law, which states that the intensity of radiation is inversely proportional to the square of the distance from the source. As the distance from the radiation source increases, the exposure rate decreases significantly; doubling the distance from the source can reduce exposure to one-quarter of the original level.

This safety practice is crucial in fluoroscopy and other radiological procedures, as it helps to protect both patients and healthcare workers from unnecessary radiation exposure. By maximizing distance whenever feasible—such as standing further away from the radiation source during a procedure—exposure can be minimized effectively, supporting the overall safety measures in radiological practices.

Other options focus on different aspects of radiation protection, such as shielding, time of exposure, and film usage, but they do not specifically address the direct relationship between distance and radiation exposure reduction.