Shielding Considerations


All Lead Radiation Shielding requirements should be calculated and determined by a certified professional radiation health physicist based on the following information.


The end user must determine the output of the X-Ray machine. (KvP). Usually, the higher the output of the machine, the higher the lead shielding requirement.


The end-user must determine the exposure per hour, day, week and year and the maximum patient exposure accumulated and projected from radiation exposure, as radiation is cumulative and unnecessary extra exposure can cause biological damage on the cellular level. Each state or province has its own maximum permissible exposure level in addition to natural radiation exposure an average person is exposed to through environmental factors like ultra violet solar, radon gas and atmospheric radiation. Ensure you check with local governing health and safety laws and codes for current compliance requirements.


All wall sections shall be calculated by your physicists in relation to the direction of the primary beam target. (Direction where it is aimed) and scatter or secondary radiation of the x-ray machine, as well as the floor or wall.


Radiation dissipates as the distance increases; usually the closer a partition is to the radiation / x-ray source, the higher the lead shielding needed.


A critical and very important factor in your calculations is the amount of time, per day, a surrounding or adjoining room common to the x-ray room will be occupied and used by your personnel or public. An example would be a simple storage room, which would have a lower use or occupancy factor, compared to a waiting room or office that would have higher use. Therefore, it is calculated room by room for all rooms connected or that are common to the x-ray room. If there is no occupancy potential, then typically no shielding will be specified or required. (I.E. Floor or roof of a single story building with no basement).


Often a physicist will take into account the existing or the proposed construction materials used or to be used of the wall/partition or flooring material, as heavy density materials can attenuate (shield) radiation to a certain degree, such as concrete, steel, plaster, block or multiple layers of drywall. This may reduce, or in some instances, eliminate your lead shielding requirements,   depending on the values of the previous factors to be considered