radiation exposure

The American Nuclear Society has put out a one-page worksheet that allows US citizens to calculate their annual dosage of ionizing radiation that they receive from their environment, and non-citizens to calculate the value to within 20%. My mom sent it to me to fill out as a laugh. Here are the calculations. All numbers are in millirem

• Where you live:

  • Effects of Cosmic Radiation
    

    Elevation:       mrem:
    Sea level-300m:  28
    300-600m:        31
    600-900m:        35
    900-1200m:       41
    1200-1500m:      47
    1500-1800m:      52
    1800-2100m:      66
    2100-2400m:      79
    
    2400-2700m:      96
    

  • Effects of Terrestrial Radiation
    1. If you live in a state bordering the Atlantic or gulf coasts, add 16 mrem.
    2. If you live on the Colorado plateau, add 63 mrem.
    3. Otherwise, add 30 mrem.
  • Home Construction
    If you live in a stone, concrete, or masonry building, add 7 mrem
  • Power Plants
    • Add .01 mrem for every Nuclear power plant within 80 km of your home.
    • Add .03 mrem for every Coal-fired power plant within 80 km of your home.

• What you ingest:

  • For carbon-14 and potassium-40 in food, and radon dissolved in water, add 40 mrem.
  • For radon from air, add 200 mrem.
  • For fallout from weapons testing, add 1 mrem.

• How you live:

  • For travel in a jet plane, add .5 mrem per hour in the air.
  • If you have porcelain crowns or false teeth, add .07 mrem.
  • If you wear a luminous wristwatch, add .06 mrem.
  • Every time you go through luggage inspection at the airport, add .002 mrem.
  • If you watch TV, add 1 mrem. The worksheet doesn't give a dosage per hour on this or the next item, oddly.
  • If you use a computer, add 1 mrem.
  • If you have a smoke detector, add .008 mrem.
  • If you use a gas camping lantern, add .2 mrem.
  • If you have a plutonium-powered pacemaker, add 100 mrem

• Medical tests

  (Remember, rem is not a measurement of radiation received, but the biological effect of radiation received, so the same physical dose given at different wavelengths, or to different parts of the body will have different rem measurements)

  Procedure:                     mrem/Procedure:
  Arm/Hand/Foot/Leg X-Ray        1
  Dental X-Ray                   1
  Chest X-Ray                    6
  Pelvis/Hip X-Ray               65
  Skull/Neck X-Ray               20
  Barium Enema X-Ray             405
  Upper GI X-Ray                 245
  CAT Scan(Head and body)        110
  Nuclear Medicine               14
      (e.g. Thyroid or Bone Scan)
  

The average annual dose for a U.S. citizen is 360 mrem. People who work with or around radioactive material are allowed exposure to up to 5000 mrem a year by international standards. The reason my mother sent this to me as a laugh is because I am currently undergoing some radiation therapy for lymphoma, and the techs told me that my prescribed 40 gray to the spinal cord is equivalent to about 4,000,000 mrem, making all of these numbers pretty much moot.

After doing some research of my own, I found that 450,000 mrem to the whole body at once is a lethal dose of radiation, and I suspected a numerical error on the part of the techs. But after talking to my rad onc doctor, it was explained to me that 9 times that much for me was OK, because

1. The area is extremely localized, to a specific area of the spine.
2. The dosage is spread out over 20 treatments, making it 200,000 mrem per session.