Radiation Protection: The Importance of Understanding the Three Basic Components to Radiation Protection

There are 3 basic components to radiation protection: Time, Distance and Shielding.

Time. Dose from ionizing radiation is directly proportional to the amount of time a person is exposed to that radiation. For staff who work around radiation frequently, reducing exposure time can be accomplished in many different ways. The most obvious is just reducing the amount of time that you are around the radiation. If your practice requires you to hold the patients for their x-rays (like in a veterinary practice), then staff should take turns holding patients. Reducing the number of repeat x-rays also reduces the exposure time. If possible, increasing kVp and consequently reducing mAs also reduces exposure time.

Distance. Radiation dose is inversely proportional to the square of the distance from the source of the radiation. If you are standing in the x-ray room during exposure for any reason – just a couple of steps backwards can drastically reduce your exposure. It is important to remember that the patient (or the object) being x-rayed is the main source of radiation for the staff and users. While there is some leakage from the head of the machine, nearly all dose to staff comes from scatter radiation created in the patient and distributed in all directions.

Shielding. All x-ray rooms and control booths should be evaluated for shielding by a medical physicist, so proper use of any x-ray equipment will not result in dose to the staff that exceeds any dangerous levels. Protective aprons, thyroid collars, and glasses should all be used when staff need to be in the room with the patient during an x-ray procedure. Mobile barriers should be used whenever possible. Lead is the most common shielding material, but any dense material will shielding the radiation to a point.