WEEK 10 RADIATION BIOLOGY

Document Sample
WEEK 10 RADIATION BIOLOGY Powered By Docstoc
					             WEEK 7
RADIATION BIOLOGY &
   PROTECTION Part 1

  FINAL




                   1
2
Sources of Ionizing Radiation
        1.   ___________
             Radiation

        2.   ___________
             Radiation

                                3
Electromagnetic Spectrum –
 shows ranges in intensity




                             4
Background Radiation has
been around a long time….




                            5
6
Radon & Uranium
most common sources




                      7
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


                                                 8
     MEDICAL IMAGING

1.   __________________x-rays
2.   _________________ x-rays

         Greatest source of
     ________ ________radiation
                                  9
10
What is the difference between x-
rays and gamma rays????


1.   Their______________________

2.   X-rays are _______ __________

3.   Gamma comes from the ______
     of the atom
                                     11
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
                                    12
                UNITS OF RADIATION
                     MEASUREMENT

1.   To ______________the amount
     of radiation

     A: Received by
          _________________
          _________________
          _________________
                                   13
        Conventional vs. SI units
                           1.   New system developed in
                                1948
1.   British units used
     since 1920’s          2.   System of Units based on
                                Metric measurements
                                developed by International
2.   United States still        Committee for Weights and
     uses this system           Measures

                           3.   1985- officially adopted

                                                             14
             Conv. Units             SI Units

            1.   RADS           1.    _______
Not equal
in amount
            2.   REMS           2.    _______

            3.   R - ROENTGEN   3.    _______

                                                15
Comparsion of Units




                      16
                  REMS
  R - ROENTGENS
                  OCCUPATIONAL EXPOSURE




  RADS –
PATIENT DOSE


                                          17
     Convenetional 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
     ________________________________
                                            18
     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 _______
                                     19
RAD to GRAY
1.       100 rad = 1     Gy    =1000   mGy
          1/100 Gy = 1 rad


2.        10 rad = .1 Gy =     = 100   mGy

3.       1000 mRad = 1 rad = .01 Gy = 10   mGy



                                             20
Radiation Equivalent Man
              Used for ________

   Traditional Unit = _________

   SI Unit = ____________ (Sv)

   1 Sv = 100 __________

   1/100 Sv =1 _________

                                   21
            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


                                                    22
                   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
                                            23
               Rad VS. Rem
1.   QF of x-ray is 1

2.   1 RAD X QF = 1 REM

3.   1 GRAY X QF = 1 SIEVERT



                               24
25
26
Why did the bunny die??
        BUNNY A                 BUNNY B

   Received 200 rads      Received 200 rads




                                                27
Why did the bunny die??
      BUNNY A            BUNNY B
200 rads x 1 for   200 rads x 20 for
X-RAY = 200 RADS     alpha =
                      4000 rads




                                       28
REM to Sievert
1.   100 rem = 1   sV      =1000   msv

1.    10 rem = .1 sV =     = 100   msv

2.   1000 mRem = 1 rem = .01 sV = 10   msv




                                         29
    RADS             REMS
   RADS          REMS

   GRAYS         SIEVERTS

   Patient     Employee
    absorbed   (technologists) =
    dose
                              30
Cell Response to Radiation




                             31
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
                                         32
Sensitivity to radiation
 based on sex




                           33
Which (Male or Female) GONADs
are external vs internal?




                            34
Which gender has gonads
from birth?




                          35
Which gender constantly
produces new reproductivecells?




                                  36
Which GENDER is more sensitive
to radiation at birth? Why?




                                 37
Dose limits




              38
         Permissible
      Occupational Dose
Annual dose :
1.   5 Rem/year 50mSv/year
2.   (5000 mrem)
Cumulative Dose
1.   1 rem x age 10mSv x
     age
                             39
    Allowable DOSE - ANNUAL
   BRITISH UNIT      SI UNIT


   5 REMS            5O mSv



                                 40
OCCUPATIONAL EXPOSURES

1.   5 REMS / YEAR

2.   BUT NOT TO EXCEED 1.25
     REM/QUARTER

                              41
       Allowable DOSE – TOTAL
      CUMMULATIVE
   BRITISH UNIT      SI UNIT


   Age x 1 rem       Age x 10msv


   Old MPD dose
    5(age-18)
                                 42
43
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)

www.ntc.gov/NRC/RG/08/08-013.html




                                                               44
Pregnancy & Embryo

1.   Mother __________worker
        (5 rem)
2.   Baby
        500_______.5 rem/ year
         .05 rem/____________
        5______
        .5 mSv / ________
                                  45
46
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

                                              47
48
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)



                                         49
          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

                               50
Review




         51
Radiation Monitoring




                       52
Radiation Monitoring
1.   Monitors measure the quantity of
     radiation received.

2.   Any radiation worker must be
     monitored

3.   to determine estimated dose exposure

                                        53
      Personnel Monitoring Devices
1.   Film Badges

2.   Thermoluminescent
     Dosimeters (TLD)

3.   Pocket Dosimeters

4.   Optically Stimulated
     Luminescence (OSL
     Dosimeters)
                                     54
TLD




      55
Film Badges –
 changed monthly




                   56
POSL




   57
58
             Field Survey Instruments
                     • “Cutie Pie”
   Geiger Muller
    counter           Ionization Chamber




                                           59
Q = t x ‫תּ‬



CUTIE
PIE




            60
Review
   What is the annual allowable
    dose for a 32 year old
    Technologist?



                               61
   What is the cummulative allowable dose
    for a 32 year old Technologist?




                                         62
63
Regulatory Agencies
1.       NCRP –
         National Council on Radiation
          Protection


2.       NRC –
         Nuclear Regulatory Committee



                                          64
REGULATORY AGENCIES
1.       NCRP - Reviews recommendation for
         radiation protection & safety.
         Distributes information re: radiation
          awareness


2.       NRC
         Makes LAWS & enforces regulations

                                                  65
QUESTIONS ?




              66

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:1
posted:2/6/2012
language:English
pages:66