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BIOLOGICAL EFFECTS OF RADIATION

BIOLOGICAL EFFECTS OF RADIATION. WILLIAM CROOKES. Image from: http://www.homeoint.org/books5/clarkehomeo/crookes.jpg. Crookes Tube. Image from: http://www.resonancepub.com/images/Crookes_Tube_.gif. WILHELM CONRAD ROENTGEN. Image from: http://www.xray.hmc.psu.edu/rci/ss1/img0003.JPG.

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BIOLOGICAL EFFECTS OF RADIATION

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  1. BIOLOGICAL EFFECTS OF RADIATION

  2. WILLIAM CROOKES Image from: http://www.homeoint.org/books5/clarkehomeo/crookes.jpg

  3. Crookes Tube Image from: http://www.resonancepub.com/images/Crookes_Tube_.gif

  4. WILHELM CONRAD ROENTGEN Image from: http://www.xray.hmc.psu.edu/rci/ss1/img0003.JPG

  5. Mrs. Roentgen’s hand Image from: http://www.xray.hmc.psu.edu/rci/ss1/img0008.JPG

  6. Early radiograph Image from: http://www.xray.hmc.psu.edu/rci/ss1/img0027.JPG

  7. Dr. Kassabian in his Philadelphia lab Image from: http://www.xray.hmc.psu.edu/rci/ss1/img0022.JPG

  8. Image from: http://www.xray.hmc.psu.edu/rci/ss1/img0050.JPG Dr. Kassabian’s hands

  9. Thomas Alva Edison Image from: http://www.cedmagic.com/history/edison-with-disc.jpg

  10. Clarence Dally Edison’s assistant Image from: http://home.gwi.net/~dnb/read/edison/edison_xrays.htm

  11. Direct Effects Direct interaction with DNA + Image from: http://www.environmental.usace.army.mil/info/technical/hp/hptraing/hprsst/11

  12. H2O H2O+ + e- H2O+ + H2O H3O+ + OH Hydrolysis of Water • Radiation ionizes a water molecule • The ion reacts with another water molecule to form the highly reactive hydroxyl radical Indirect Effect Image from: http://www.environmental.usace.army.mil/info/technical/hp/hptraing/hprsst/13

  13. DNA “Target Molecule”

  14. POSSIBLE EFFECTS OF RADIATION • Radiation may pass through cell without doing any damage. • Damage may occur, but be repaired. • The damaged cell may reproduce itself in its damaged form. • The cell may die. DAMAGE CAN BE REPAIRED Image from: http://www.xps.org/dna.jpg

  15. The Law of Bergonié and Tribondeau This law states… • Stem cells are radiosensitive; mature cells are radioresistant. • Younger tissues and organs are radiosensitive. • Tissues with high metabolic activity are radiosensitive. • A high growth rate for tissues result in increased radiosensitivity.

  16. The following tissue types are radiosensitive: • Germinal…reproductive cells of the ovary and testis • Hematopoietic (blood forming) tissues…red bone marrow, spleen, lymph nodes and thymus • Intestinal crypt cells – cells on the surface of the intestine

  17. The least radiosensitive would be tissue such as: • Muscle • Nerve

  18. EARLY EFFECTS VS. LATE EFFECTS

  19. EARLY EFFECTS (Prompt Effects) After a high, single radiation exposure in a short period of time ~ 25 Rem or greater Image from: http://kalarte.com/marder/radiation.jpg

  20. Non-Stochastic Health Effects • Acute effects are “Non-stochastic” effects • The effects become more severe as the exposure increases. • In other words, the amount of the dose does not determine the probability of the effect, it determines the severity of the effect.

  21. ACUTE RADIATION SYNDROME Prodromal Stage Latent Period Images from: http://www.mscare.com/s0008/img/fatigue.jpg http://www.public.iastate.edu/~bolson/happywoman.jpg Manifest Illness Stage

  22. ACUTE RADIATION SYNDROMES • Hematologic Syndrome • Gastrointestinal Syndrome • Central Nervous System Syndrome

  23. Hematologic Syndrome 200 – 1,000 Rad • Prodromal Stage: Mild symptoms appear within a few hours and last for several days • Latent Period: May last up to 4 weeks • Manifest Illness: Vomiting, diarrhea, fatigue and fever – Decline in blood cells – Recovery in 2 to 4 weeks…May last up to 6 months • Possible death due to infection, dehydration or hemorrhage

  24. Gastrointestinal Syndrome 1,000 – 5,000 Rad • Prodromal Stage: Vomiting and diarrhea occur within hours and last up to one day • Latent Period: Lasts 3-5 days • Manifest Illness: Nausea, vomiting and diarrhea – Worsens to bloody stools • Death within 4 to 10 days after exposure primarily due to intestinal cell damage – Also damage to blood-forming tissue results in hemorrhaging and dehydration.

  25. Central Nervous System Syndrome Greater than 5,000 Rad • Prodromal Stage: Severe nausea and vomiting within a few minutes – Nervousness, confusion, burning skin, vision loss…possible loss of consciousness • Latent Period: May last up to 12 hours, or not at all • Manifest Illness: Disorientation, loss of muscle control, breathing problems, seizures, coma • Death always within a few days of exposure – due to increased fluid in brain (pressure) – Death occurs before hematologic and gastrointestinal symptoms appear

  26. LD 50/60 • The dose of radiation to the whole body that will result in death within 60 days to 50% of the subjects receiving the dose…if no treatment is given • For humans…approximately 350 rad • People have survived up to 850 rad if treatment is received

  27. OTHER EARLY EFFECTS(Lower doses or localized) • SKIN • GONADS • BLOOD COUNT REDUCTION • CELLULAR CHROMOSOME DAMAGE

  28. SKIN EXPOSURE • ERYTHEMA • Threshold approximately 200 rad • SED50 approximately 600 rad • ULCERATION • At higher doses • EPILATION • Localized hair loss

  29. ANGIOPLASTY EXPOSURE 6-8 WEEKS AFTER 3RD ANGIOPLASTY 5 MONTHS LATER 22 MONTHS LATER Photographs courtesy of Thomas B. Shope, Ph.D. (FDA)

  30. OVARIES AND TESTES EXPOSURE • 200 rad – Temporary sterility • 500 rad – Permanent sterility • 10 rad – Possible genetic mutation (testes) • 25-50 rad – Possible genetic mutation (ovaries)

  31. HEMATOLOGIC EFFECTS • A dose as low as about 25 rad may cause a reduction in blood cell counts Image from: http://www.easi.org/nape/apslides/22_blood.gif

  32. CYTOGENETIC EFFECTS • Doses as low as 5 rad may cause some cellular chromosome aberrations Image from: http://medschool.umaryland.edu/departments/radiationoncology/rorl/images/morganF2.jpg

  33. LATE EFFECTS After an acute exposure or an extended chronic exposure Take months to years to become evident Some risk at any dose Image from: http://kalarte.com/marder/radiation.jpg

  34. Stochastic Health Effects • Late effects are “Stochastic” effects • The effects become more probable as the exposure increases. • In other words, the amount of the dose determines the probability of the effect, it does not determine the severity of the effect.

  35. Late Effects • Cataracts • Cancer (including leukemia) • Mental retardation (fetal doses)

  36. LATE EFFECTSRISK ESTIMATES • Difficult to quantify • Epidemiological studies needed

  37. A-BOMB SURVIVORS Hiroshima Image from: http://www.aip.org/history/lawrence/images/bomb-plane_bomb.jpg

  38. A-BOMB SURVIVORS Image from: http://osulibrary.orst.edu/specialcollections/coll/atomic/atomic-qv04-0309.jpg

  39. Hiroshima & Nagasaki • 300,000 total population • 100,000 killed • 100,000 survivors with significant radiation doses • Increased leukemia occurrence • Increased mental retardation (8-15 weeks gestation) Image from: http://www.ww2guide.com/atomic.jpg

  40. MARSHALL ISLANDS • 1940’s & 1950’s • Nuclear Testing Fallout • Thyroid Cancer data Image from: http://www.amphilsoc.org/library/exhibits/treasures/images/abomb3sm.jpg

  41. EARLY RADIOLOGISTS Increased occurrence of leukemia and other effects Image from: http://www.xray.hmc.psu.edu/rci/ss2/img0009.JPG

  42. ANKYLOSING SPONDYLITIS PATIENTS • 1940’s and 1950”s • Arthritic spine condition • 100 – 4,000 rad • Permanent cure • Increased occurrence of leukemia Image from: http://hcd2.bupa.co.uk/images/factsheets/ankspond.gif

  43. RADIUM DIAL PAINTERS • 1920’s and 1930’s • Dose of up to 50,000 rad to the bone • Increased occurrence of bone cancer Image from: http://www.anl.gov/OPA/frontiers96arch/f96photo/43.gif

  44. URANIUM MINERS • Radon exposure • Increased occurrence of lung cancer Image from: http://www.radiationsafety.ca/picture%20files/mining02.jpg

  45. RISK MODELS Image from: http://bfa.sdsu.edu/ehs/doseresponse.gif

  46. RISK MODELLinear Non-threshold Image from: http://4d.ehrs.upenn.edu:8080/RSXITW/images/slide16.gif

  47. CANCER RISK ESTIMATES ONE MILLION PEOPLE EXPOSED TO 1 RAD 50 to 150 deaths from radiation induced cancer occurring within 25 years 100,000 PEOPLE EXPOSED TO 100mrad/YEAR 19,000 would die from cancer without exposure Increased cancer deaths estimated at about 550

  48. ALARA Assuming linear non-threshold model All radiation exposure poses some risk Image from: http://4d.ehrs.upenn.edu:8080/RSXITW/images/slide16.gif

  49. PREGNANCY RISK • 1st trimester has most risk • Possible effects: • Death • Congenital abnormalities • Cancer induction • Growth impairment • Mental retardation • Genetic effects Image from:http://www.diabetesuffolk.com/Managing Diabetes/Planning a pregnancy.asp

  50. Effects of 10 Rad in Utero Radiologic Science for Technologists, 7th edition, Stewart C. Bushong, (pg. 512)

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