1. What type of radiation are humans exposed to on a daily basis?
    background radiation
  2. a form of ionizing radiation that is ubiquitous in the environment
    background radiation
  3. What are 2 types of naturally occuring background radiation?
    • cosmic
    • terrestrial
  4. radiation that originates from the stars and the sun
  5. a person's exposure to cosmic radiationdepends on________
  6. the higher the altitude, the__________the exposure to cosmic radiation
  7. radiation that occurs naturally and is emitted from radioactive material present in the earth and air
    terrestrial radiation
  8. whatare 2 examples of terrestrial radiation?
    • potassium - 40
    • uranium
  9. The average dose of background radiaton received by an individual in the U.S. ranges from ________to________mrads per year
    150-300 (0.0015-0.003 Gy per year)
  10. true or false. background radiation exposure may vary according to geographic location
  11. geographic areas that contain more radioactive materials are associate with increased amounts of__________
    terrestrial radiation
  12. geographic areas at higher elevations are associated with increased amounts of________radiation
    cosmic radiation
  13. What is the single largest contributer to artficial radiation exposure?
    medical radiation
  14. What are 5 examples of medical radiation?
    • medical radiographic procedures
    • dental radiography
    • fluoroscopy
    • nuclear medicine
    • radiation therapy
  15. What type of radiation exposure equals the average yearly dose from all other exposures combined, and typically accounts for half of the total exposure recieved?
    medical radiation
  16. the likelihood of adverse effects or death resulting from exposure to a hazard
  17. in dental radiograph, risk is the likelihood of an adverse affect, specifically ______ _______, occurring from exposure to ionizing radiation
    cancer induction
  18. What is the estimated potential risk of dental radiography inducing fatal cancer in an idividual?
    3 in 1,000,000
  19. What is the riskof a person developing cancer spontaneoulsy?
    3300 in 1,000,000 (much higher than from dental radiography)
  20. true or false. risks from dental radiography are not significantly greater than the risks of other everyday activities in life
  21. What is the dose required to produce cancer in the thyroid gland?
    6000 mrad (0.06 Gy)
  22. What are the 4 critical organs in dental radiographic procedures?
    • thyroid gland
    • bone marrow
    • skin
    • eyes
  23. What is the average dose to the thyroid gland with rectangular collimation, d-speed film, long PID, 20-film series)
    • 6 mrads
    • 0.00006 Gy
    • 1/1000 of the dose necessary to induce thyroid cancer
  24. What areas account for a small percentage of active bone marrow in dental radiography?
    areas of maxilla and mandible
  25. The risk of cancer induction (leukemia) is dirctly associated with the amound of blood-producing tissues_________ and the_________
    • irradiated
    • dose
  26. What dose is leukemia usually induced at?
    5000 mrad (0.05 Gy)
  27. What is the average bone marrow dose from PA radiography?
    • 1-3 mrads
    • 0.00001-0.00003 Gy
    • between 2000 and 5000 films would have to be exposed to induce leukemia
  28. What dose is required tocause erythema?
    • 250 rads
    • 2.5 Gy
    • in a 14 day period
  29. How many films would have to be taken in a 14 day period to cause erythema?
  30. How many mrads are necessar to induce cataract formation?
    • 200,000 mrads
    • 2 Gy
  31. What is the average surface dose to the cornea of the eye in dental radiography?
    • 60 mrads
    • 0.0006 Gy
  32. What are 4 factors of patient protection that exposure depends on?
    • film speed
    • collimation
    • technique
    • exposure factors
  33. a longer source to film distance will_____ radiation exposure
Card Set
radiation risks