Radiation
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This document provides an overview of radiation and its effects on the human body. It defines radiation as the emission of energy through waves or particles. Ionizing radiation like alpha particles, beta particles, gamma rays, x-rays and neutrons have sufficient energy to damage atoms and DNA. Sources include naturally occurring radioactive materials in the environment and man-made sources like nuclear reactors, medical equipment, and consumer products. Exposure to high doses of radiation can damage cells and lead to health issues like cancer, but risks are low from everyday sources like medical x-rays. The document recommends limiting radiation exposure through reducing time spent near sources, increasing distance, and using shielding when possible.
Radiation
- 1. FYI: RADIATION Kristine Marie Romallosa Radiation Protection Services Philippine Nuclear Research Institute
- 2. Things to know about radiation.. • Ionizing radiation • Types of ionizing radiation • Sources of ionizing radiation • Radioactive materials
- 4. What is Radiation? Radiation is the process of emitting energy through a medium or space in the form of waves or particles
- 5. WAVES PARTICLES What is Radiation? Radiation is the process of emitting energy through a medium or space in the form of waves or particles
- 6. WAVES PARTICLES NON-IONISING IONISING What is Radiation? Radiation is the process of emitting energy through a medium or space in the form of waves or particles
- 7. What is Ionizing Radiation? Type of radiation that has sufficient energy to knock-out electrons in atoms and molecules electron Ionizing radiation
- 8. Types of Ionizing Radiation Alpha particles Beta particles Gamma rays X-rays Neutrons
- 9. Types of Ionizing Radiation Alpha Beta Gamma
- 10. Types of Ionizing Radiation Alpha Beta Gamma
- 11. Radiation Hazards ....neutrons, x-rays & gamma rays are more hazardous for the entire body.. ....alpha & beta emitters are more hazardous When they are ingested or inhaled..
- 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. 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. 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. 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. 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 days 1 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. Sources of Ionising Radiation • Natural Sources • Man-made Sources
- 19. Natural Source: Common Building Materials
- 20. Natural Sources: Food, Water, Air
- 21. Natural Sources: Your body
- 22. Man-made sources • Nuclear reactors • Medicine • Food & agriculture • Industry • Household uses • Nuclear weapons • Archaeology & Geology
- 23. Man-Made Sources : Modern Health Care Conventional Diagnostic X-rays Nuclear medicine for therapy & diagnosis
- 24. Man-Made Sources : Modern Health Care Radiation therapy for Fluoroscopic imaging of cancer treatment body systems
- 25. Man-Made Sources: Industry Gauges for levels in cans Food irradiation & contents of bottles
- 26. Man-Made Sources: Industry Soil density & Moisture content analysis of roads Industrial radiography for Thickness of steel & Integrity of welds
- 27. Households & buildings Smoke detectors Static eliminators
- 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. What could happen to the body when exposed to radiation?
- 30. Biological effects • Biological effects on living cells 1. Cells experience DNA damage that are detected & repaired 2. DNA damage not repaired and causes cell death 3. Cell experiences DNA mutation and may induce cancer
- 32. Radiation Dose Absorbed radiation dose (energy/mass) received by the body taking into account the radiation sensitivity of specific tissues and body organs measure of the biological effect of a particular type of radiation on organs or tissues Sieverts ( Sv ) milliSv (mSv) = 1/1000 Sv microSv (µSv) = 1/1,000,000 Sv nanoSn (nSv) = 1/1,000,000,000 Sv
- 33. Exposure Limits
- 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 workers 250 - 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 in 3000 - 6000 survivors
- 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 workers 250 - 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 in 3000 - 6000 survivors
- 37. Summary of Radiation Effects
- 38. Relative Risks: Loss of Life Expectancy Cohen,B.L. Catalog of risks extended and updated, Health Physics 61/3:317-333 (1991)
- 39. Relative Risks: Loss of Life Expectancy Cohen,B.L. Catalog of risks extended and updated, Health Physics 61/3:317-333 (1991)
- 42. HOW CAN YOU CONTROL RADIATION EXPOSURE?
- 43. How to Control Exposure? TIME DISTANCE SHIELDING Time distance shielding
- 44. Minimize TIME The less time that people are exposed to a radiation source, the lesser the absorbed dose.
- 45. Maximize DISTANCE • the greater the distance from a source of penetrating radiation, the less the overall exposure
- 46. Incorporate shielding Barriers of lead, concrete or water can stop radiation or reduce radiation intensity.
- 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. Radiation Controls NOT YET NECESSARY IN THE PHILIPPINES • Evacuation (maximizing distance) • Sheltering (shielding, minimizing inhalation) • Restriction of food products in AFFECTED 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. Regular Bulletins at PNRI website www.pnri.dost.gov.ph
- 50. Questions?
- 51. That’s all.. Thank you!!!!