Do not adjust your set
Radiation Safety  in the Mortuary  (II) John Saunderson Radiation Protection Adviser
Programme <ul><li>Review of radiation risks </li></ul><ul><li>Potential source of radiation in the mortuary </li></ul><ul>...
Deterministic Effects (“threshold effects”) <ul><li>Large number of cells killed – physiological effect, e.g. </li></ul><u...
Stochastic Effects (“chance effects”) <ul><li>Where cells mutated in a such a way as to cause </li></ul><ul><ul><li>Cancer...
<ul><li>Radiation in Hospitals </li></ul><ul><li>Radioactive substances </li></ul><ul><ul><li>Nuclear medicine </li></ul><...
External & Internal Hazards <ul><li>X-rays </li></ul><ul><ul><li>External </li></ul></ul><ul><li>Radioactive substance </l...
 
Leakage
X-rays -  some numbers <ul><li>For an abdominal X-ray </li></ul><ul><ul><li>Patient dose = 1 mSv (milli-Sievert) </li></ul...
All doses should be kept <ul><li>A s </li></ul><ul><li>L ow </li></ul><ul><li>A s </li></ul><ul><li>R easonably </li></ul>...
Basic Principles <ul><li>Time </li></ul><ul><li>Distance </li></ul><ul><li>Shielding </li></ul>
Distance <ul><li>Double distance =  1 / 4  dose  </li></ul><ul><li>Triple distance =  1 / 9 th  dose . </li></ul>
Shielding
Shielding
Typical Transmission  through Shielding  (90 kV) <ul><li>0.25 mm lead rubber apron    8.5% </li></ul><ul><li>0.35 mm lead...
“ Radioactive Patients ” <ul><li>Patients may be radioactive if </li></ul><ul><li>they’ve been injected with or swallowed ...
Radioactive Decay - half life
Radiation measurements <ul><li>Becquerels – Bq – measures activity </li></ul><ul><ul><li>Banana – 13 Bq </li></ul></ul><ul...
Nuclear Medicine Scan <ul><li>Patient injected with or swallows a radioactive pharmaceutical </li></ul><ul><li>Gamma camer...
 
Nuclear Medicine scan -  some numbers <ul><li>For a bone scan  (technetium-99m, half life = 6 hours) </li></ul><ul><ul><li...
Body of diagnostic patient <ul><li>Dose to patient similar to annual background radiation </li></ul><ul><li>External dose ...
Thyroid treatments with radio-iodine <ul><li>Hyperthyroidism / thyrotoxicosis   </li></ul><ul><ul><li>overactive thyroid -...
Other unsealed source therapies <ul><li>Phosphorus-32 for polycythemia  (too many red blood cells) </li></ul><ul><li>Yttri...
Body of unsealed source therapy patient <ul><li>Patient will have letter saying how many days restrictions apply. If they ...
Brachytherapy  (radioactive implants) <ul><li>Intracavity afterloading </li></ul><ul><li>Iridium wire afterloading </li></...
LDR-Selectron
HDR-microSelectron
Iridium Implant
Iodine-125 seeds in Prostate 4.5 x 0.8 mm “seeds”
Body with iodine-125 seeds <ul><li>Very short range radiation (HVT = 2 cm tissue) </li></ul><ul><li>External dose rate to ...
Nuclear Powered Pacemaker <ul><li>Contain 114 GBq of plutonium-238  </li></ul><ul><li>Not used for past 20 years </li></ul...
Casualties Contaminated by Low Level Radioactive Substances <ul><li>Life saving treatment will override all other action <...
f i n
Threshold risks Very large doses only The bigger the dose, the more  severe  the effect Staff doses  never  this big
Cancer risks It is assumed that any dose of radiation could potentially cause cancer. The bigger the dose, the more  likel...
Tc-99m 0.017 uGy/h/MBq@1m Bone scan 600 MBq
Unsealed source therapy -  some numbers <ul><li>For thyrotoxicosis dose  (iodine-131, half life = 8 days) </li></ul><ul><u...
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Radiation safety in the Mortuary Part 2

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Radiation safety in the Mortuary Part 2

  1. 1. Do not adjust your set
  2. 2. Radiation Safety in the Mortuary (II) John Saunderson Radiation Protection Adviser
  3. 3. Programme <ul><li>Review of radiation risks </li></ul><ul><li>Potential source of radiation in the mortuary </li></ul><ul><li>Safety precautions and actions </li></ul><ul><li>Any questions? </li></ul>
  4. 4. Deterministic Effects (“threshold effects”) <ul><li>Large number of cells killed – physiological effect, e.g. </li></ul><ul><ul><li>Skin burn </li></ul></ul><ul><ul><li>Cateracts </li></ul></ul><ul><ul><li>“ Radiation sickness” </li></ul></ul><ul><li>No risk below threshold doses </li></ul><ul><li>Bigger dose above threshold, more severe the effect </li></ul><ul><li>Very unlikely in mortuary . </li></ul>
  5. 5. Stochastic Effects (“chance effects”) <ul><li>Where cells mutated in a such a way as to cause </li></ul><ul><ul><li>Cancer </li></ul></ul><ul><ul><li>Hereditary disease </li></ul></ul><ul><li>Risk proportional to dose </li></ul><ul><li>e.g abdomen X-ray risk = risk of dying in a traffic accident in next year </li></ul><ul><li>Minimise risk by keeping doses a s l ow a s r easonably a chievable </li></ul><ul><li>A.L.A.R.A. </li></ul>
  6. 6. <ul><li>Radiation in Hospitals </li></ul><ul><li>Radioactive substances </li></ul><ul><ul><li>Nuclear medicine </li></ul></ul><ul><ul><li>Pathology </li></ul></ul><ul><ul><li>Radiotherapy </li></ul></ul><ul><ul><li>Contaminated casualties </li></ul></ul><ul><li>X-ray sources </li></ul><ul><ul><li>Radiology </li></ul></ul><ul><ul><li>Radiotherapy </li></ul></ul><ul><ul><li>Pathology </li></ul></ul><ul><li>Radiation in Mortuary </li></ul><ul><li>Radioactive substances </li></ul><ul><ul><li>Nuclear medicine patients </li></ul></ul><ul><ul><li>Some radiotherapy patients </li></ul></ul><ul><ul><li>Contaminated casualties </li></ul></ul><ul><ul><li>Plutonium pacemakers </li></ul></ul><ul><li>X-ray sources </li></ul><ul><ul><li>Mobile X-ray (?) </li></ul></ul>
  7. 7. External & Internal Hazards <ul><li>X-rays </li></ul><ul><ul><li>External </li></ul></ul><ul><li>Radioactive substance </li></ul><ul><ul><li>Internal </li></ul></ul><ul><ul><li>External </li></ul></ul>
  8. 9. Leakage
  9. 10. X-rays - some numbers <ul><li>For an abdominal X-ray </li></ul><ul><ul><li>Patient dose = 1 mSv (milli-Sievert) </li></ul></ul><ul><ul><li>Scatter dose < 0.04 mSv at 1 metre </li></ul></ul><ul><li>Legal dose limit </li></ul><ul><ul><li>for radiation worker = 20 mSv/y </li></ul></ul><ul><ul><li>Public = 1 mSv/y </li></ul></ul><ul><li>Natural UK background dose = 2.3 mSv/y . </li></ul>
  10. 11. All doses should be kept <ul><li>A s </li></ul><ul><li>L ow </li></ul><ul><li>A s </li></ul><ul><li>R easonably </li></ul><ul><li>A chievable </li></ul><ul><li>The ALARA Principle . </li></ul>
  11. 12. Basic Principles <ul><li>Time </li></ul><ul><li>Distance </li></ul><ul><li>Shielding </li></ul>
  12. 13. Distance <ul><li>Double distance = 1 / 4 dose </li></ul><ul><li>Triple distance = 1 / 9 th dose . </li></ul>
  13. 14. Shielding
  14. 15. Shielding
  15. 16. Typical Transmission through Shielding (90 kV) <ul><li>0.25 mm lead rubber apron  8.5% </li></ul><ul><li>0.35 mm lead rubber apron  5% </li></ul><ul><li>2 x 0.25 mm apron  2.5% </li></ul><ul><li>2 x 0.35 mm apron  1.0% </li></ul><ul><ul><ul><ul><ul><li>Double brick wall  0.003% </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Plasterboard stud wall  32% </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Solid wooden 1” door  81% </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Code 3 lead (1.3 mm)  0.1% . </li></ul></ul></ul></ul></ul>
  16. 17. “ Radioactive Patients ” <ul><li>Patients may be radioactive if </li></ul><ul><li>they’ve been injected with or swallowed radioactive pharmaceuticals </li></ul><ul><li>they have solid radioactive sources surgically implanted </li></ul><ul><li>they have been involved in an accident with radioactive materials . </li></ul>
  17. 18. Radioactive Decay - half life
  18. 19. Radiation measurements <ul><li>Becquerels – Bq – measures activity </li></ul><ul><ul><li>Banana – 13 Bq </li></ul></ul><ul><ul><li>Natural radioactivity in a human – 3 kBq </li></ul></ul><ul><ul><li>Myocardial Perfusion Scan – 80 MBq (2 mCi) </li></ul></ul><ul><ul><li>Thyroid cancer - 8 GBq </li></ul></ul><ul><ul><li>Radiotherapy Co-60 source – 150 TBq (4 kCi) </li></ul></ul><ul><li>Sieverts – Sv – dose </li></ul><ul><ul><li>Fatal dose – 4 Sv </li></ul></ul><ul><ul><li>Background UK dose = 2 mSv a year </li></ul></ul><ul><ul><li>Chest X-ray – 20 uSv </li></ul></ul>
  19. 20. Nuclear Medicine Scan <ul><li>Patient injected with or swallows a radioactive pharmaceutical </li></ul><ul><li>Gamma camera traces where that radiopharmaceutical is concentrated . </li></ul>
  20. 22. Nuclear Medicine scan - some numbers <ul><li>For a bone scan (technetium-99m, half life = 6 hours) </li></ul><ul><ul><li>Patient dose = 3 mSv </li></ul></ul><ul><ul><li>External dose < 0.01 mSv/h at 1 metre </li></ul></ul><ul><ul><li>Activity injected = 600 MBq </li></ul></ul><ul><ul><li>ALI for radiation workers = 1000 MBq </li></ul></ul><ul><ul><li>To reach public dose limit = 50 MBq </li></ul></ul><ul><li>Legal dose limit </li></ul><ul><ul><li>for radiation worker = 20 mSv/y </li></ul></ul><ul><ul><li>Public = 1 mSv/y </li></ul></ul><ul><li>Natural UK background dose = 2.3 mSv/y . </li></ul>
  21. 23. Body of diagnostic patient <ul><li>Dose to patient similar to annual background radiation </li></ul><ul><li>External dose rate to others – insignificant </li></ul><ul><li>Half life </li></ul><ul><ul><li>Technetium-99m, 6 hours </li></ul></ul><ul><ul><li>Thallium-201, 73 days </li></ul></ul><ul><li>Contamination hazard? </li></ul><ul><ul><li>“ no extra precautions to those employed when caring out post-protems/embalming” </li></ul></ul><ul><li>No restrictions on disposal of body </li></ul><ul><li>If in doubt, call Nuclear Medicine Department . </li></ul>
  22. 24. Thyroid treatments with radio-iodine <ul><li>Hyperthyroidism / thyrotoxicosis </li></ul><ul><ul><li>overactive thyroid - 400 MBq </li></ul></ul><ul><li>Thyroid cancer </li></ul><ul><ul><li>must destroy all tumour - 3000 MBq </li></ul></ul><ul><li>c.f. thyroid scan - 0.2 MBq . </li></ul>
  23. 25. Other unsealed source therapies <ul><li>Phosphorus-32 for polycythemia (too many red blood cells) </li></ul><ul><li>Yttrium-90 colloid for arthritic conditions </li></ul><ul><li>Strontium-90 for bone metastases . </li></ul>
  24. 26. Body of unsealed source therapy patient <ul><li>Patient will have letter saying how many days restrictions apply. If they still apply </li></ul><ul><ul><li>Seek advice of Medical Physics Expert (MPE) from Nuclear Medicine Department </li></ul></ul><ul><li>External dose rate to others – low </li></ul><ul><li>Half life, iodine-131, 8 days </li></ul><ul><li>Contamination hazard? </li></ul><ul><ul><li>assume yes </li></ul></ul><ul><ul><li>Avoid spread of contamination </li></ul></ul><ul><li>Consult MPE on disposal of body </li></ul><ul><ul><li>Thyrotoxicosis – OK </li></ul></ul><ul><ul><li>Thyroid cancer – OK after 23 day max. . </li></ul></ul>
  25. 27. Brachytherapy (radioactive implants) <ul><li>Intracavity afterloading </li></ul><ul><li>Iridium wire afterloading </li></ul><ul><li>Iridium pins </li></ul><ul><li>Iodine-125 seeds . </li></ul>
  26. 28. LDR-Selectron
  27. 29. HDR-microSelectron
  28. 30. Iridium Implant
  29. 31. Iodine-125 seeds in Prostate 4.5 x 0.8 mm “seeds”
  30. 32. Body with iodine-125 seeds <ul><li>Very short range radiation (HVT = 2 cm tissue) </li></ul><ul><li>External dose rate to others – low </li></ul><ul><ul><li>Patients advised to avoid close contact (<10 cm) with children and pregnant women for 2 months </li></ul></ul><ul><li>Half life = 60 day </li></ul><ul><li>Avoid cremation before one year (or consider removing sources) </li></ul><ul><li>Post-mortem? – risk assessment – call the Radiotherapy Department . </li></ul>
  31. 33. Nuclear Powered Pacemaker <ul><li>Contain 114 GBq of plutonium-238 </li></ul><ul><li>Not used for past 20 years </li></ul><ul><li>Never used in Hull & E. Yorks. </li></ul><ul><li>No longer fitted (NiCd batteries replaced nuclear batteries) </li></ul><ul><li>Patients wear a labelled bracelet </li></ul><ul><li>Should always be removed before buriel/cremation (although designed to withstand 850 o C) </li></ul><ul><li>Annual dose limit exceeded if held for over 1600 hours . </li></ul>
  32. 34. Casualties Contaminated by Low Level Radioactive Substances <ul><li>Life saving treatment will override all other action </li></ul><ul><li>Seek expert advice from radiation physicist a.s.a.p. </li></ul><ul><li>Avoid spread of contamination </li></ul><ul><li>Collect everything that comes into contact with radioactive substances (e.g. clothes, swabs, fluids, etc.) . </li></ul>
  33. 35. f i n
  34. 36. Threshold risks Very large doses only The bigger the dose, the more severe the effect Staff doses never this big
  35. 37. Cancer risks It is assumed that any dose of radiation could potentially cause cancer. The bigger the dose, the more likely the effect will occur, (but it will probably never occur). i.e. a bit like crossing the road - the more times you cross the more likely you are to be run over, but probably never will.
  36. 38. Tc-99m 0.017 uGy/h/MBq@1m Bone scan 600 MBq
  37. 39. Unsealed source therapy - some numbers <ul><li>For thyrotoxicosis dose (iodine-131, half life = 8 days) </li></ul><ul><ul><li>External dose < 23 mSv/h at 1 metre </li></ul></ul><ul><ul><li>Activity swallowed = 400 MBq </li></ul></ul><ul><ul><li>ALI for radiation workers = 0.8 MBq </li></ul></ul><ul><li>Max. activity for burial or cremation without precautions = 400 MBq . </li></ul>

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