1 WEEK 7 RADIATION BIOLOGY & PROTECTION Part 1 FINAL

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3 Sources of Ionizing Radiation 1. ___________ Radiation 2. ___________ Radiation

4 Electromagnetic Spectrum – shows ranges in intensity

5 Background Radiation has been around a long time….

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7 Radon & Uranium most common sources

8 AVE population exposure= 20 – 30 mrem/year 1. In some places in United States average ________mrem/yr Majority due to _________ gas 2. Many places on earth receive more than _________ mrem/yr from radon

9 MEDICAL IMAGING 1. __________________x-rays 2. _________________ x-rays Greatest source of ________ ________radiation

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11 What is the difference between x- rays and gamma rays???? 1. Their______________________ 2. X-rays are _______ __________ 3. Gamma comes from the ______ of the atom

12 Terminology to cover 1. Units of Measurement 2. ALARA 3. DOSE – 1. Cumulative 2. Annual 4. Target theory 5. Direct vs. Indirect Hit 6. Somatic vs. genetic

13 UNITS OF RADIATION MEASUREMENT 1. To ______________the amount of radiation A: Received by _________________

14 Conventional vs. SI units 1. British units used since 1920’s 2. United States still uses this system 1. New system developed in System of Units based on Metric measurements developed by International Committee for Weights and Measures officially adopted

15 Conv. Units SI Units 1. RADS 2. REMS 3. R - ROENTGEN 1. _______ 2. _______ 3. _______ Not equal in amount

16 Comparsion of Units

17 R - ROENTGENS RADS – PATIENT DOSE REMS OCCUPATIONAL EXPOSURE

18 Conventional Unit of ROENTGEN (R) 1. SI unit =__________ 2. The quantity of radiation exposure in_______________ 3. Measures __________of the x-ray tube 4. Does not indicate the actual ________________________________

19 RADIATION ABSORBED DOSE (RAD) SI = GRAY (Gy) 1. Measures the _____________ of energy ___________ by any medium (__________) 2. 1 Gray (Gy) = 100 _______ 3. 1/100 Gy = 1 _______

20 RAD to GRAY rad = 1 Gy =1000 mGy 1/100 Gy = 1 rad rad =.1 Gy = = 100 mGy 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 1. Different _________ of radiation produce different responses 2. The unit of dose ___________, expressed as __________________________________ 3. Used for ____________(employee) exposures 4. 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 1. QF of x-ray is RAD X QF = 1 REM 3. 1 GRAY X QF = 1 SIEVERT

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

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

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

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

31 Cell Response to Radiation

32 Response of cells to radiation Cell sensitivity is dependant on: 1. Type of cell 2. Type of damage received 3. 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 reproductive cells?

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

38 Dose limits

39 Permissible Occupational Dose Annual dose : 1. 5 Rem/year 50mSv/year 2. (5000 mrem) Cumulative Dose 1. 1 rem x age 10mSv x age

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

41 OCCUPATIONAL EXPOSURES 1. 5 REMS / YEAR 2. BUT NOT TO EXCEED 1.25 REM/QUARTER

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

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44 Declared Pregnant Worker 1. ____ badges provided 1. 1 worn at collar (___________________exposure) 2. 1 worn inside apron at waist level (____ exposure) 2. Under 5 rem – _____________________ risk 3. Risk _____________________ above 15 rem 4. Recommend ________ (spontaneous) 25 rem 5. (“Baby exposure” approx 1/1000 of ESE)

45 Pregnancy & Embryo 1. Mother __________worker (5 rem) 2. Baby 500_______.5 rem/ year.05 rem/____________ 5______.5 mSv / ________

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47 Fetus Exposure 1. Radiation exposure is most harmful during the __________ trimester of pregnancy 2. ______________ Exposure limit 0.05 rem or 0.5 mSv PER MONTH 0.5 rem or 5 mSv total gestation

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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

51 Review

52 Radiation Monitoring

53 Radiation Monitoring 1. Monitors measure the quantity of radiation received. 2. Any radiation worker must be monitored 3. to determine estimated dose exposure

54 Personnel Monitoring Devices 1. Film Badges 2. Thermoluminescent Dosimeters (TLD) 3. Pocket Dosimeters 4. Optically Stimulated Luminescence (OSL Dosimeters)

55 TLD

56 Film Badges – changed monthly

57 POSL

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59 Field Survey Instruments Geiger Muller counter “Cutie Pie” Ionization Chamber

60 Q = t x תּ CUTIE PIE

61 Review What is the annual allowable dose for a 32 year old Technologist?

62 What is the cummulative allowable dose for a 32 year old Technologist?

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64 Regulatory Agencies 1. NCRP – National Council on Radiation Protection 2. NRC – Nuclear Regulatory Committee

65 REGULATORY AGENCIES 1. NCRP - Reviews recommendation for radiation protection & safety. Distributes information re: radiation awareness 2. NRC Makes LAWS & enforces regulations

66 QUESTIONS ?