Radiation exposure and how not to die from it

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First my friends…Everything is radioactive and radiating us with alpha particles, beta particles, gamma rays and x-rays.  Bananas, rocks, concrete, lightning, the sun, the cosmos, your dog, your spouse, your friends, the trees, and the air all have radioactive components to them.  Your own body and eyeballs are emitting radiation.  24 hours a day, 7 days a week for as long as the planet has existed and for as long as it will exist.

So, nature is radioactive?  You betcha!  And so are the big scary toxic nuclear waste pits (Hanford, Washington ..ahem ahem) and nuclear power plants (451 and counting (source).  And modern medicine is full of radioactive tools for imaging, testing, cancer treatment, etc…  Some household smoke detectors have radioactive Americium-241 inside them.

The more that I learn about radioactivity, the more I come to understand that life would be drastically different without it.  Technically, life wouldn’t exist without the Sun, which has been fusing 620 million metric tons of Hydrogen, per second, for 4.6 billion years, releasing torrential amounts of ionizing radiation, heat and light.  Modern medicine was revolutionized by the discovery of X-rays.  Nuclear medicine is revolutionizing other critical medical imaging procedures.  Gamma rays are being used to sterilize food and medical equipment and also used to destroy cancer tumors.

But Matt!  I thought radiation was bad!  Radiation in its most basic form is the movement of energy in the form of waves, rays or particles.  If I throw a baseball and it hits you in the face, I have just radiated my kinetic energy into you.  When you listen to music, the speakers are radiating sound waves into your ear drums.  When you flip on a light switch, you are causing photons to radiate from your lights and into your eyes.  When you turn on your oven, you are causing heat to radiate from the heating element into your tray of cookies.  When the police officer speaks into his walkie talkie, he is radiating the air with radio waves that are detected by the antennas on other walkie talkies.

When you eat a delicious banana, you are ingesting Potassium.  A fraction of that Potassium is Potassium-40, a radioactive isotope that occurs in nature.    Potassium-40 radiates weak beta particles and gamma rays.  It accounts for 50% of the radioactivity in the human body, and in a 175lb man, decays/radiates 4000-5000 times per second.  In my lifetime, this radiation has happened 4,966,920,000,000 times.

So why I am I not dead already?  I am being bombarded from every direction, inside and out.  The reason is simply that my total exposure to the radiation is very very small.  Today I am going to explain things using a unit that measures radiation dosage.  This unit is the Sievert.  One Sievert will make you very sick, and not much more will kill you.

  • 1 Sv = Very sick, almost dead
  • 0.05 sV (50mSv) = Radiation worker one-year dose limit
  • 0.004 sV (4mSv) = Normal yearly exposure to a human from natural sources
  • 0.00025 Sv (250μSv) = EPA yearly release limit for a nuclear power plant
  • 0.00002 Sv (20μSv) = Chest x-ray
  • 0.00001 Sv (10μSv) = Daily natural radiation exposure
  • 0.0000001 Sv (0.1μSv) = Eating a banana
  • 0.00000005 Sv (0.05μSv) = Sleeping next to someone
  • 1 Sv = Eating one million bananas in a year
  • 1 Sv = Total 250 year radiation exposure to a human from natural sources

0.14892 Sv = The radiation you would be exposed to if you held the Fiestaware plate (featured below) next to your body for an entire year.

0.001752 Sv = The radiation you would be exposed to if you were three feet away from the same Fiestaware plate for an entire year. This is 25% of what you would pick up from natural sources in the same year.  Three feet of distance decreased the radiation by 98%.

0.0010512 Sv = The radiation you would be exposed to 9 feet away from the same Fiestaware plate for an entire year.  This is the same level of radiation as the house next door where no Fiestaware is present.

It comes down to three simple components of reducing radiation exposure: time, distance, shielding.  In the examples above, I can reduce the radiation hazard from my Fiestaware plate by spending less time around it, by staying further away from it, and by shielding it.  If I was around the plate for 3 minutes, at a distance of 3 feet, my exposure would be 0.000000003 Sv, which is like eating 1/100th of a banana.

Last fun fact, when I shielded the plate with a box of my favorite Unicorn Cereal, radiation dropped from 17.5 μSv/hr to 0.45 μSv/hr.  Make sure you feed your kids this cereal, it will keep the radioactive bananas from killing them. <3

I hope you have enjoyed this post and that you will enjoy the video I put together:

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