CAMRT Radiography Practice Exam

Which of the following is NOT one of the three cardinal rules of radiation protection?

1. Time

2. Distance

3. Shielding

4. Shielding policies

The correct answer is: Shielding policies

The concept of the three cardinal rules of radiation protection is critical for minimizing exposure to ionizing radiation. These rules are designed to protect both the patient and healthcare workers. The three cardinal rules are: 1. **Time** - Reducing the amount of time spent near a radiation source decreases exposure, as exposure is directly proportional to the duration of time spent in a radiation field. 2. **Distance** - Increasing the distance from the radiation source helps to reduce exposure, based on the inverse square law, which states that the intensity of radiation decreases with the square of the distance from the source. 3. **Shielding** - Using appropriate barriers or materials to absorb or block radiation serves to protect individuals from exposure. This can include lead aprons, walls, or other protective devices specifically designed for this purpose. While shielding policies may relate to practices and regulations surrounding the use of shielding, they are not one of the fundamental principles or rules themselves. Instead, shielding is one of the three essential strategies. Therefore, referring to "shielding policies" does not fit within the framework of the three cardinal rules of radiation protection, making it the correct choice for the question.