1. WEEK 7 RADIATION BIOLOGY & PROTECTION Part 1
FINAL

3. Sources of Ionizing 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
Some natural background in the United States average mrem/yr with the majority due to radon gas, a daughter product of uranium decay. 
However, many places on earth receive more than 1000 mrem/yr from radon.

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

15. Conv. Units SI Units RADS REMS R - ROENTGEN _______
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 10 rad = .1 Gy = = 100 mGy
1000 mRad = 1 rad = .01 Gy = 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
Not all types of radiation produce the same responses in living tissue
The unit of dose equivalence, expressed as the product of the absorbed dose in rad (or gray) and quality factor.
RAD x QF = REM
used for occupational 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

25. Very low energy =
More destructive

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

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 100 rem = 1 sV =1000 msv 10 rem = .1 sV = = 100 msv
1000 mRem = 1 rem = .01 sV = 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:
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. Allowable DOSE - ANNUAL
BRITISH UNIT
5 REMS
SI UNIT
5O mSv

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

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

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)
Must declare pregnancy – 2 badges provided
1 worn at collar (Mother’s exposure)
1 worn inside apron at waist level
Under 5 rad – negligible risk
Risk increases above 15 rad
Recommend abortion (spontaneous) 25 rad
(“Baby exposure” approx 1/1000 of ESE)

45. Pregnancy & Embryo Mother __________worker Baby (5 rem)
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

51. Review

52. Radiation Monitoring

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

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

55. TLD

56. Film Badges – changed monthly

57. POSL

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

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?

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

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

66. QUESTIONS ?