When no radiation shield is available, what is the minimal distance the operator should stand from the patient's head?

The appropriate distance an operator should maintain from a patient's head when no radiation shield is available is two metres. This distance is based on the principles of radiation safety, which emphasize minimizing exposure to ionizing radiation.

At two metres away, the intensity of radiation significantly decreases due to the inverse square law, which states that the intensity of radiation is inversely proportional to the square of the distance from the source. By standing farther away, the operator effectively reduces their exposure risk while still being able to perform necessary procedures. Additionally, this distance helps to ensure the operator is in a safer position should any stray radiation occur during procedures such as X-rays.

In contrast, shorter distances, such as one metre, one and a half metres, or three metres, may not provide the same level of safety or may not be considered necessary based on current safety guidelines and standards. Therefore, two metres is considered a balanced approach, ensuring adequate protection while still allowing for procedural efficiency.