WEEK 7 RADIATION BIOLOGY & PROTECTION Part 1

1. WEEK 7RADIATION BIOLOGY & PROTECTION Part 1 FINAL

3. Sources of Ionizing Radiation • ___________ Radiation • ___________Radiation

4. Electromagnetic Spectrum –shows ranges in intensity

5. Background Radiation has been around a long time….

7. Radon & Uranium most common sources

8. AVE population exposure= 20 – 30 mrem/year • In some places in • United States average ________mrem/yr • Majority due to _________ gas   • Many places on earth • receive more than _________ mrem/yr from radon

9. MEDICAL IMAGING • __________________x-rays • _________________ x-rays Greatest source of ________ ________radiation

11. What is the difference between x-rays and gamma rays???? • Their______________________ • X-rays are _______ __________ • Gamma comes from the ______ of the atom

12. Terminology to cover • Units of Measurement • ALARA • DOSE – • Cumulative • Annual • Target theory • Direct vs. Indirect Hit • Somatic vs. genetic

13. UNITS OF RADIATION MEASUREMENT • To ______________the amount of radiation A: Received by • _________________ • _________________ • _________________

14. British units used since 1920’s United States still uses this system New system developed in 1948 System of Units based on Metric measurements developed by International Committee for Weights and Measures 1985- officially adopted Conventional vs. SI units

15. RADS REMS R - ROENTGEN _______ _______ _______ Conv. Units SI Units Not equal in amount

16. Comparsion of Units

17. REMS OCCUPATIONAL EXPOSURE R - ROENTGENS RADS – PATIENT DOSE

18. Convenetional Unit of ROENTGEN (R) • SI unit =__________ • The quantity of radiation exposure in_______________ • Measures __________of the x-ray tube • Does not indicate the actual ________________________________

19. RADIATION ABSORBED DOSE (RAD) SI = GRAY (Gy) • Measures the _____________ of energy ___________ by any medium (__________) • 1 Gray (Gy) = 100 _______ • 1/100 Gy = 1 _______

20. RAD to GRAY • 100 rad = 1 Gy =1000 mGy • 1/100 Gy = 1 rad • 10 rad = .1 Gy = = 100 mGy • 1000 mRad = 1 rad = .01 Gy = 10 mGy

21. Radiation Equivalent Man Used for ________ • Traditional Unit = _________ • SI Unit = ____________ (Sv) • 1 Sv = 100 __________ • 1/100 Sv =1 _________

22. RADIATION EQUIVALENT MAN(REMS) SI UNITS = SIEVERT • Different _________ of radiation produce different responses • The unit of dose ___________, expressed as • __________________________________ • Used for ____________(employee) exposures • Can be used when for dose of patient

23. QUALITY FACTOR Qualifies what the damage is from different types of radiation • Example: QF for X-ray is 1 QF for alpha is 20 • Alpha is 20 x more damaging to tissue

24. Rad VS. Rem • QF of x-ray is 1 • 1 RAD X QF = 1 REM • 1 GRAY X QF = 1 SIEVERT

27. BUNNY A Received 200 rads BUNNY B Received 200 rads Why did the bunny die??

28. BUNNY A 200 rads x 1 for X-RAY = 200 RADS BUNNY B 200 rads x 20 for alpha = 4000 rads Why did the bunny die??

29. REM to Sievert • 100 rem = 1 sV =1000 msv • 10 rem = .1 sV = = 100 msv • 1000 mRem = 1 rem = .01 sV = 10 msv

30. RADS GRAYS Patient absorbed dose REMS SIEVERTS Employee (technologists) = RADS REMS

31. Cell Response to Radiation

32. Response of cells to radiation • Cell sensitivity is dependant on: • Type of cell • Type of damage received • Type of radiation exposed to

33. Sensitivity to radiation based on sex

34. Which (Male or Female) GONADs are external vs internal?

35. Which gender has gonads from birth?

36. Which gender constantly produces new reproductivecells?

37. Which GENDER is more sensitive to radiation at birth? Why?

38. Dose limits

39. Permissible Occupational Dose Annual dose : • 5 Rem/year 50mSv/year • (5000 mrem) Cumulative Dose • 1 rem x age 10mSv x age

40. BRITISH UNIT 5 REMS SI UNIT 5O mSv Allowable DOSE - ANNUAL

41. OCCUPATIONAL EXPOSURES • 5 REMS / YEAR • BUT NOT TO EXCEED 1.25 REM/QUARTER

42. BRITISH UNIT Age x 1 rem Old MPD dose 5(age-18) SI UNIT Age x 10msv Allowable DOSE – TOTALCUMMULATIVE

44. Declared Pregnant Worker • ____ badges provided • 1 worn at collar (___________________exposure) • 1 worn inside apron at waist level (____ exposure) • Under 5 rem – _____________________ risk • Risk _____________________ above 15 rem • Recommend ________ (spontaneous) 25 rem • (“Baby exposure” approx 1/1000 of ESE) www.ntc.gov/NRC/RG/08/08-013.html

45. Pregnancy & Embryo • Mother __________worker • (5 rem) • Baby • 500_______.5 rem/ year • .05 rem/____________ • 5______ • .5 mSv / ________

47. Fetus Exposure • Radiation exposure is most harmful during the __________ trimester of pregnancy • ______________ Exposure limit • 0.05 rem or 0.5 mSv PER MONTH • 0.5 rem or 5 mSv total gestation

49. Education and Training Exposures • Student’s must never hold patients during exposures • Effective dose limit (Annual) • 0.1 rem or 1 mSv • (1/50 of Technologist’s dose)

50. PUBLIC EXPOSURE NON MEDICAL EXPOSURE • 10 % of Occupational exposure • 0.5 rad or 500 mrad or 50mgray • Under age 18 and Students • 0.1 rem 10 mrem 1mSv