Radiation

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Radiation

  1. 1. FYI: RADIATION Kristine Marie Romallosa Radiation Protection Services Philippine Nuclear Research Institute
  2. 2. Things to know about radiation..• Ionizing radiation• Types of ionizing radiation• Sources of ionizing radiation• Radioactive materials
  3. 3. What is Radiation?
  4. 4. What is Radiation?Radiation is the process ofemitting energy through amedium or space in the formof waves or particles
  5. 5. WAVES PARTICLESWhat is Radiation?Radiation is the process of emitting energy through a medium or space in the formof waves or particles
  6. 6. WAVES PARTICLES NON-IONISING IONISINGWhat is Radiation?Radiation is the process of emitting energy through a medium or space in the formof waves or particles
  7. 7. What is Ionizing Radiation?Type of radiation that has sufficient energy to knock-out electrons in atoms and molecules electron Ionizing radiation
  8. 8. Types of Ionizing Radiation Alpha particles Beta particles Gamma rays X-rays Neutrons
  9. 9. Types of Ionizing RadiationAlphaBetaGamma
  10. 10. Types of Ionizing RadiationAlpha BetaGamma
  11. 11. Radiation Hazards....neutrons, x-rays & gamma raysare more hazardous for theentire body......alpha & beta emitters are morehazardous When they areingested or inhaled..
  12. 12. Sources of Ionising Radiation• Radioactive materials – Radioactive materials continuously emit radiation – Cannot be turned OFF• Radiation emitting devices or equipment (e.g. X-ray machines) – Machines can be turned ON and OFF – When turned OFF, no radiation is emitted
  13. 13. Sources of Ionising Radiation• Radioactive materials – Radioactive materials continuously emit radiation – Cannot be turned OFF• Radiation emitting devices or equipment (e.g. X-ray machines) – Machines can be turned ON and OFF – When turned OFF, no radiation is emitted
  14. 14. Radioactive Materials• unstable atoms that DECAY by emitting particles and/or electromagnetic radiation• Release of ENERGY• decays to form a more stable nuclide• Results in the formation of new elements• There are about more than 2,000 unstable or radioactive nuclides
  15. 15. Radioactive Materials• The rate at which the is radiation emitted is called the activity• Becquerel (Bq) OR Curie (Ci)1 Bq = 1 disintegration per second (dps) 1 Ci = 3.7 x 1010 Bq• Half-life • The TIME taken for one half the nuclei in the sample to decay
  16. 16. Radioactive Materials• The rate at which the is radiation emitted is called the activity• Becquerel (Bq) OR Curie (Ci) Cs-137 ~ 30 years I-131 ~ 8 days1 Bq = 1 disintegration per second (dps) Sr-90 ~ 28 yrs 1 Ci = 3.7 x 1010 Bq• Half-life • The TIME taken for one half the nuclei in the sample to decay
  17. 17. Sources of Ionising Radiation• Natural Sources• Man-made Sources
  18. 18. www.ocrwm.doe.gov/.../radiation-pathways.jpg
  19. 19. Natural Source: Common Building Materials
  20. 20. Natural Sources: Food, Water, Air
  21. 21. Natural Sources: Your body
  22. 22. Man-made sources• Nuclear reactors• Medicine• Food & agriculture• Industry• Household uses• Nuclear weapons• Archaeology & Geology
  23. 23. Man-Made Sources : Modern Health Care Conventional Diagnostic X-rays Nuclear medicine for therapy & diagnosis
  24. 24. Man-Made Sources : Modern Health Care Radiation therapy for Fluoroscopic imaging of cancer treatment body systems
  25. 25. Man-Made Sources: IndustryGauges for levels in cans Food irradiation & contents of bottles
  26. 26. Man-Made Sources: Industry Soil density &Moisture contentanalysis of roads Industrial radiography for Thickness of steel & Integrity of welds
  27. 27. Households & buildingsSmoke detectors Static eliminators
  28. 28. Global radiation dose Global Radiation Dose (UNSCEAR 2000) nuclear 12% medical 12% natural radon 38% natural internal 10% natural external 16% natural cosmic 12%
  29. 29. What could happen to the body when exposed to radiation?
  30. 30. Biological effects• Biological effects on living cells 1. Cells experience DNA damage that are detected & repaired2. DNA damage not repaired and causes cell death3. Cell experiences DNA mutation and may induce cancer
  31. 31. Radiation Effects
  32. 32. Radiation Dose Absorbed radiation dose (energy/mass) received bythe body taking into account the radiation sensitivityof specific tissues and body organsmeasure of the biological effect of a particular type ofradiation on organs or tissuesSieverts ( Sv )milliSv (mSv) = 1/1000 SvmicroSv (µSv) = 1/1,000,000 SvnanoSn (nSv) = 1/1,000,000,000 Sv
  33. 33. Exposure Limits
  34. 34. Occupationalexposure toradiation
  35. 35. Radiation Doses Received (mSv) 0.4 - 1.5 one chest X-ray 0.1 Background (per hr), Red Forest Chernobyl Exclusion zone 1-3 Mammogram 3 US average annual natural background 10 natural background Kerala coast, India dose limit for workers 50 Cranial CT scan 100 small increase in cancer risk dose limit for Fukushima NPP workers250 - 1000 Temporary nausea, blood cell changes, sterility in males; Nausea, fatigue, vomiting, blood cell changes, loss of appetite,1000 - 3000 sterility in males, death possible early death in 50% of those exposed, sterility and cataracts in3000 - 6000 survivors
  36. 36. Radiation Doses Received (mSv) 0.4 - 1.5 one chest X-ray 0.1 Background (per hr), Red Forest Chernobyl Exclusion zone 1-3 Mammogram 3 US average annual natural background 10 natural background Kerala coast, India dose limit for workers 50 Cranial CT scan 100 small increase in cancer risk dose limit for Fukushima NPP workers250 - 1000 Temporary nausea, blood cell changes, sterility in males; Nausea, fatigue, vomiting, blood cell changes, loss of appetite,1000 - 3000 sterility in males, death possible early death in 50% of those exposed, sterility and cataracts in3000 - 6000 survivors
  37. 37. Summary of Radiation Effects
  38. 38. Relative Risks: Loss of Life ExpectancyCohen,B.L. Catalog of risks extended and updated, Health Physics 61/3:317-333 (1991)
  39. 39. Relative Risks: Loss of Life ExpectancyCohen,B.L. Catalog of risks extended and updated, Health Physics 61/3:317-333 (1991)
  40. 40. www.ocrwm.doe.gov/.../radiation-pathways.jpg
  41. 41. Radiation exposure
  42. 42. HOW CAN YOU CONTROL RADIATION EXPOSURE?
  43. 43. How to Control Exposure? TIMEDISTANCESHIELDING Time distance shielding
  44. 44. Minimize TIMEThe less time that people are exposed to a radiation source, the lesser the absorbed dose.
  45. 45. Maximize DISTANCE• the greater the distance from a source of penetrating radiation, the less the overall exposure
  46. 46. Incorporate shieldingBarriers of lead, concrete or water can stopradiation or reduce radiation intensity.
  47. 47. Radiation Controls• Evacuation (maximizing distance)• Sheltering (shielding, minimizing inhalation)• Restriction of food products in affected areas (minimizing ingestion)• Restriction in water intake in affected areas (minimizing intake)• Medical intervention (taking of pills)• Radiation monitoring
  48. 48. Radiation Controls NOT YET NECESSARY IN THE PHILIPPINES• Evacuation (maximizing distance)• Sheltering (shielding, minimizing inhalation)• Restriction of food products inAFFECTED AREAS IN JAPAN affected areas (minimizing ingestion) ARE LOCALIZED• Restriction in water intake in affected areas (minimizing intake)• Medical intervention (taking of pills)• Radiation monitoring RADIATION MONITORING IS ONGOING
  49. 49. Regular Bulletins at PNRI websitewww.pnri.dost.gov.ph
  50. 50. Questions?
  51. 51. That’s all.. Thank you!!!!

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