millisievert
Quick Summary
The millisievert (mSv) is a unit used in physics to measure the dosage of ionizing radiation, taking into account its biological effectiveness. It is a sub-unit of the sievert (Sv), where 1 mSv equals 1/1,000 Sv. One millisievert is equivalent to the energy of 10 ergs of gamma radiation transferred to one gram of living tissue.12
The average person receives about 2.4 mSv annually from natural sources like cosmic rays and radon gas. Medical procedures, such as a chest CT scan, can result in a dose of 6.8 mSv. Regulatory bodies set limits for radiation exposure for workers, with the U.S. Nuclear Regulatory Commission limiting those handling radioactive materials to 50 mSv per year. A dose of 1 Sv can cause acute radiation sickness, and 10 Sv is fatal.1
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