1. Health, Safety and Environment www.hse.ubc.ca

2. Units of Radiation

3. Post-doc ACTIVITY Becquerel

4. Activity - Becquerel Becquerel (Bq) = 1 disintegration per second (dps) 1 Bq = 27 picoCuries 1 kiloBq (kBq) = 27 nanoCuries 1 MegaBq (MBq) = 27 microCuries (µCi) 1 GigaBq (GBq) = 27 milliCuries (mCi) 1 TeraBq (TBq) = 27 Curies

5. Post-doc ACTIVITY Becquerel EXPOSURE INTENSITY C/kg

6. Exposure Intensity Coulomb =6.25 x10 18 elementary charges A flow of one Coulomb per sec equals one Ampere Coulomb/kg of air = 3876 Roentgens Not applicable to particle emission Does not predict tissue effects at high energies Mainly used for calibration of X-ray machines

7. ABSORBED DOSE Gray Post-doc ACTIVITY Becquerel EXPOSURE INTENSITY C/kg

8. Absorbed Dose Gray = Unit of absorbed dose = Joule/kg of tissue Replaced rad: radiation absorbed dose 1 Gy = 100 rads

9. ABSORBED DOSE Gray Post-doc ACTIVITY Becquerel EXPOSURE INTENSITY C/kg DOSE EQUIVALENT Seivert

10. Dose Equivalent Sievert : Replaced rem :radiation equivalent in man Numerical product of Grays times a quality factor Q of the emission Sv = Gray x Q Relative Biological Effectiveness 1 SV = 100rems

11. Quality Factors *Different types of radiation produce different amounts of biological damage for a given energy deposition: eg. alpha causes much more damage than an equal absorbed dose of gamma radiation. Q=20 for alpha particles, 1 for gamma,beta

12. ABSORBED DOSE Post-doc ACTIVITY EXPOSURE INTENSITY DOSE EQUIVALENT