Which method can be used to control external exposure to radiation?

The method that effectively controls external exposure to radiation is based on time, distance, and shielding, which are the foundational principles of radiation protection.

Time refers to the duration of exposure; minimizing the time spent near a radiation source reduces the overall dose received. The less time an individual spends in close proximity to radiation, the lower the exposure to harmful effects.

Distance is a key factor in radiation protection. Increasing the distance from the radiation source reduces the intensity of exposure, as radiation intensity decreases with the square of the distance from the source. This concept is often referred to as the inverse square law, which highlights the importance of maintaining as much distance as possible when working around radiation.

Shielding involves the use of barriers made from appropriate materials to absorb or deflect radiation. Common materials used for shielding include lead, concrete, and other high-density materials, which can significantly reduce the amount of radiation that reaches an individual.

Combining these three methods effectively minimizes exposure to radiation and enhances safety for workers and patients in medical environments. Each method plays a complementary role in developing a comprehensive radiation safety strategy.