History/Groups/Units Flashcards
Watch Dial Painters
Exposed to ingestion of large amounts of radium due to drawing bristles of sable paint brushes between lips to “sharpen” point during the the 1920s and 30s primarily in Illinois and New Jersey. Incorporated into bone tissue causing decalcification of bone, sarcoma, and carcinoma
Navajo Miners
Exposed to ingestion of uranium dust due to mining in the 1950s and 60s. 50% dies of lung cancer. Mines in NM and AZ that employed over 15,000 minors, mainly navajo. Average dose was 10Sv (1000 rem). Contaminated homes/families with radioactive dust brought home on clothing.
Early Radiology Workers
High Exposure of radiation exposure to hands/face due to no protective equipment from 1896-1910’s, resulting in an increased incidence of aplastic anemia and leukemia.
Thorotrast Patients
Early contrast agent used in angiography containing 25% Thorium Dioxide (Alpha Emitter), uptake into the liver and spleen causing an increased incidence of liver cancer, cancer of the spleen, biliary carcinoma, and angiosarcoma.
Infant Thymus Glands
In an attempt to treat enlargement of the thymus gland, radiation treatments were used on infants in the 1940’s & 50s. Enlargement due to infections/respiratory distress in infants. Theraputic dose of 1.2-60 Gray (120-6000 rads).
Marshall Islanders
Fallout pattern of radiation in air in Bikini Atoll in 1954. An unexpected wind shift during a nuclear test carried the fallout pattern over the inhabited islands. The average dose to thyroid = 12 Gray (1200 rad)
Hiroshima and Nagasaki
Radiation exposure due to atomic bomb killing approximately 90,000 immediately and 70,000 injured. All survivors with various degrees of radiation exposure. Studied survivors found increased incidence of leukemia, thyroid and lung cancer and bone/breast cancer.
Chernobyl
In 1986 a meltdown/explosion at a nuclear power plant with no international notification, discovered by Swedish monitoring systems. Soviets tried to cover it up. VERY limited early assistance/evacuation efforts; delays in administering aid resulted in million of people developing radiation induced illnesses.
Fukushima Daiichi
Radioactive debris released due to an earthquake and tsunami. Earthquake struck causing shutdown of reactors, backup generators kicked on and were then flooded by tsunami causing a loss of power to run the cooling pumps leading to overheating of the reactor core with meltdown.
Exposure in Air
Measured by:
Roentgen (R - traditional)
or
SI Units - Air Kerma (Gya - Grays in Air)
Roentgens
Used to measure ionization in air as a result of an exposure to X-ray or gamma rays
1 R = 2.58 x 10(-4) coulombs per kilogram
Air Kerma, Grays in Air (Gya)
Measures the amount of energy absorbed in any medium
1Gy = 100 rads
Energy Absorbed
Dose to humans
Rads
Traditional units for measuring energy absorbed
RAD = Radiation Absorbed Dose
Gray in Tissue (Gyt)
SI unit for measuring energy absorbed
Gyt = Grays in Tissue
Dose Equivelent
Tissue damage due to dose
Rem
Traditional unit for measuring dose equivelent.
Different types of radiation produce different types of biological effects in living tissue.
Rem = RAD x QF (absorbed dose x quality factor)
Sievert
SI unit for measuring dose equivelent
Activity
Amount of a radioactive material used commonly in radiation therapy of nuclear medicine.
Curie
Traditional unit for measuring activity (Ci) or radionuclide decay.
Becquerel
SI unit for measuring activity
LD 50/60
The dose to kill 50% of a population within 60 days after exposure
lethal dose is approximately
300-400 rads without medical intervention
Doubling Dose
measures the effectiveness of radiation in causing mutations
Male Sterility dose
the higher the dose, the greater the risk
Temporary Male Sterility Dose
200 rads may cause temporary sterility for as long as 12 months
Permanent Male Sterility Dose
500-600 rads may cause this
Female Sterility Dose
The amount of dose determines the risk of sterility
Temporary Female Sterility Dose
200 rads will usually result in temporary female sterility
Permanent Female Sterility Dose
a single dose of 500 rads will cause permanent sterility
Uranium Half Life
U238 has a half life of 4.5 billion years
Uranium
A fuel for nuclear power and weapons
Since the 1940s
radiation workers have no documented increase in adverse health effects due to their occupational exposure.
Thymus gland
As a infant, this gland is basically fully sized (very large for an infant)
1 out of 300
Survivors of Hiroshima/Nagasaki died of malignancy attributed to the whole body radiation exposure; a tribute to the human bodes ability to repair itself
Radiologic Units
Used to quantify the amount of radiation healthcare workers and patients receive, used for dose, exposure, and air exposure.
Traditional Units
In the USA we routinely use these whereas the rest (about) of the world uses SI units
LD 50/30 vs 50/60
For humans, the LD 50/60 is typically used due to our slower recovery rate and inaccurate results if only 30 days are given to determine whether or not death will occur.
Doubling Dose
Measures the radiation dose that causes the number of spontaneous mutations in a given generation to increase by 2 (double). Estimated to be a mean dose of 156 rem and was determined by the Japan bomb survivors
Low Dose - Sterility
a dose as low as 10 rads can depress the sperm count, may also cause genetic mutations in further generations
Sterility in females
Ovaries are very radiosensitive as a child/teen. From age 20-30 they are least radiosensitive. From age 30 on, their radiosensitvity increases constantly until menopause because the new ova being destroyed are not replenished.
Sterility in Females - Small dose
Doses as small as 10 rads may cause menstrual irregularities and may cause genetic damage. Women should wait 30 days after a significant X-ray exposure before attempting to achieve conception.
Dose Response Curve
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