THE SUPER SHORT VERSION
True, there is no SAFE level of radiation, but if I contract brain cancer, I am going to be looking angrily at my cell phone…or I might remember that day I visited the Star-ship Enterprise and mooned the dilithium crystals. That probably wasn’t my smartest maneuver.
OK, for serious, I think this question deserved an answer because I am getting correspondence from people that show all kinds of data, but very little explanation of how to interpret the data. I am NOT in the radiology field, so what I have researched here represents what I am willing to accept as my personal truth, and I am sharing in case someone else wants to save themselves a little time sifting through the underbelly of radiological equationimuhfications!
THE SHORT ANSWER
There is no such thing as a safe level of radiation. The radiation you get from just living on this planet COULD kill you. Now, once you’ve accepted that, understand that the radiation reaching you from Japan is barely measurable comparative to the amount of radiation you receive just by walking around inside your house (unless your house has radon gas…in which case, your house poses a much greater threat than Japan’s radiation).
THE LONGER ANSWER
The first thing I wanted to do was determine a measurement of radiation that is reaching the United States. It varies based on where you are, but the numbers I kept finding were…well…non existent. As a rough guideline, it seems like a number between 100-200 Counts Per Minute (cpm) is considered “background noise” when measuring radiation. All the measurements I saw, fluctuated between 50 and 150. Then there would be text NEXT to the measurement saying “this is elevated!”
So, let’s pluck a number. Let’s say they see a 10% or 20% elevation… that would be between 5 and 30 cpm. I will go with 15 cpm (see how scientific this feels?). Let’s pretend (because I haven’t been able to quantify) that the amount of extra radiation reaching the average US populace from Japan is 15 cpm.
The next thing is to relate a cpm to some level of safety. For example, 200 is the starting point before some folks would even begin to research if there MIGHT even be contamination. 200 – 400 is “suspected” contamination… but let’s say we wanted another number to compare to, just so we can feel extra snuggly wuggly about the radiation reaching the US.
So I read this article that talked about Sieverts. This is a magical representation of radiation’s potential impact on a living thing. If a living thing is exposed to 1 Sievert (Sv) of immediate radiation, it’s pretty-much guaranteed that it will experience radiation sickness, but may not die from the exposure. If you want more than that, then I have references you can peruse down below.
For perspective’s sake, if you get a medical procedure done such as an x-ray or CT scan, you could be exposed to anywhere from .1 to 20 millaSieverts (mSv) of radiation. It takes 1,000 mSv to equal 1 Sievert (and at 1 Sv, you will more than likely get sick, but it may not kill you) .
So, now that we have a basic understanding of the mSv, I need to convert 15 cpm to mSv so we can get an idea of the “hypothetical” threat level coming from Japan’s reactor. Well, I did a bunch of reading and my calculations lead me to this: 15 cpm is about .0625 mR/min or about .625 mSv/min.
Thusly and Therefore, if you compare the 100 cpm (or 4.2 mSv/min) that comes into your life just by existing on our planet to the .625 mSv/min that MIGHT be coming from Japan… Japan doesn’t even stack up to the background noise, much less pose a threat.
DO YOU SEE WHAT I SEE?
And I ain’t talking stars…yet. If you have a background in this stuff, please check my math. If you don’t have a background in this stuff, please feel free to check my math. But, what I am seeing is, this amount doesn’t seem like it matters. And so I repeat: True, there is no SAFE level of radiation, but if I contract brain cancer, I am going to be looking angrily at my cell phone…or I might remember that day I visited the Star-ship Enterprise and mooned the dilithium crystals. That probably wasn’t my smartest maneuver.
Conversion of 200 cpm = .05 mR (millirems)/hour and also interpreting the meter readings
Radiation Network sites “elevated readings” which lead me to pretend 15cpm was coming from Japan, but that is a total wild guess at best
Link to Harvard Health Blog (medical procedure mSv exposure table and hey, any link to Harvard improves credibility right? hoo hoo haa)