The exact amount of radiation exposure in an x-ray procedure varies depending on the part of the body receiving the x-ray. Some examples of common x-ray procedures and approximate exposures are:
Single chest x-ray: 0.02 mSv (2 mrem)
Dental x-ray (four bitewings): 0.004 mSv (0.4 mrem)
Limbs and joints: 0.06 mSv (6 mrem)
Abdomen: 0.7 mSv (70 mrem)
Mammogram (four images): 0.13 mSv (13 mrem)
Generally, the radiation received during an x-ray is small compared to other radiation sources (e.g., radon in the home). The average annual radiation dose from natural background sources (for comparison) is 3.0 mSv (300 mrem). For more information on radiation sources, see the EPA’s Radiation Sources & Doses page or calculate your radiation dose on the EPA’s Radiation Dose Calculator page.
mSv and mrem are units used to measure radiation dose; for more information, see Radiation Terms and Units on EPA.gov.