Radiation Exposure Units of Measure
Energy Absorbed from γ-rays and X-rays
Old SI Units Conversion
Radiation absorbed dose Rad Gray (Gy) 1 Gy = 100 rad
1 cGy = 1 rad
Roentgen equivalent mass Rem Sievert (Sv) 1 Sv = 100 rem
Average Annual Exposure = 360 mRem or 0.0036 Sv
Chest X-Ray = 5-10 mrem CT Scan = 5,000 mRem (0.05 Sv)
Activity for Radiation Emission of Radionuclides
Unit of Decay Ol d SI Unit Disintergrations/sec
Curie Ci - 1 Ci = 3.7 X 1010 dps
1 Ci = 37 MBq
Becquerel - Bq 1 Bq = 1 dps
1 MBq = 109 dps
Environmental (Natural) Radiation Exposure
Average Annual Exposure
360 mRem or 0.0036 Sv
Sources:
Cosmic radiation and radon
Cigarette smoke
Medical devices
Home appliances
Pharmaceutical agent
Specific Exposures
5-10 mRem: Flight from New York to Los Angeles
5-10 mRem: Chest radiograph
5,000 mRem (0.05 Sv): CT Scan
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