Radiation dosage chart

The title says it all. This is for established factual (we hope) things.

Radiation dosage chart

Postby Doug Coulter » Fri Aug 16, 2013 5:49 pm

I keep losing and finding this - and it's useful. From XKCD to give credit where due. Too many people don't understand all this (including some nuclear physicists). There have been many attempts to convert "counts" to physiological damage - some seem fairly well thought out, some not so much, none proven to my complete satisfaction. For example, you can be exposed to a lot of low energy X rays, and do little damage, or externally to almost infinite alpha rays (helium nuclei) with just about zero damage - the dead layer of skin you have on your body stops them all harmlessly. I might debate some of the number conversions used for neutrons - fast ones are supposedly worse than slow - but the slow ones are what activate (make radioactive) things in your body, that do you harm later on. While it should be obvious, I'll just (re) state that there's a big difference between things that get into you, versus things that you're exposed to externally - which might just pass on through without doing any damage, or be stopped harmlessly by your skin. That's why you can handle say, uranium ore with relative safety - but by golly, don't breathe the dust. Radon, for example, has a short half life and is a gas you can breathe in - but its decay products are themselves nasty - and solid and some are soluble - and hang around to kill you later.
This isn't simple stuff. Yet, we have a lot of potassium-40 in us - we are radioactive. I see about 120 cpm on 2" sq of geiger counter here, from cosmic rays and natural (and nuke test from the cold war years) - and you're a lot bigger than 2" sq, so you're getting more than that, and some of it's pretty nasty. Here's the chart:
radiation.png
Radiation dosage chart from XKCD

As usual here, click the chart for a bigger, more readable version. I think many will be surprised at what they see here.


Now, when someone is trying to scare you, they play the units specsmanship game (I'd quote a guy calling himself George Washiington on zerohedge as one of these scare mongers). For example - he'd use Bequerels, which gives you huge numbers, rather than say sieverts, which measure actual damage a little better,
http://en.wikipedia.org/wiki/Sievert

But that's not all there are. There are rads, rems, and so on. This is a result of many attempts to find a unit that means something to humans.
http://en.wikipedia.org/wiki/Roentgen_equivalent_man

And then, to really scare you, the one that creates the biggest numbers, and the unit mostly used by scaremongers about fusors, Fukishima, and so forth.
http://en.wikipedia.org/wiki/Bequerel

Which is counts/second. While a single count *might* defeat the amazing DNA built in error-correction we all have, it's real doubtful, and you're getting quite a few anyway, being bigger than my geiger counter. Let's see, at my location (which is on the low side for background radiation, indoors, vented basement (no radon) and so on, assuming I look like about a square foot to the sky (more if I'm relaxing, less if I stand up), then I'm getting about 72 bq continuously....but there's one heck of a lot of atoms in my body to divide that among...
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: Radiation dosage chart

Postby johnf » Fri Aug 16, 2013 7:00 pm

Well said Doug
I tried to correct some mis-info on 4HV forum
but was getting shot down by the uninformed
what most do not realise is that coal fired power plants put out around what Chenobyl released in its accident every year
but sure not some of the nasties but the radiation count figures are similar.
also most clay soils contain around 1 ounce of uranium per ton hence the radon output how does this figure with the organic purists??.
I could go on but I will not!!!
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Re: Radiation dosage chart

Postby Doug Coulter » Fri Aug 16, 2013 7:27 pm

Thanks, John,

This was a dual-use post. There was a discussion of this by a rad fear-monger on another board, and since they wouldn't let me post the pic, I did it here and linked it from there. But I use this one myself...and as I said, I keep losing the printed copy or using the back for scribbling...so I figured it'd be safer here where I can always find it. Or direct rad-phobes to it. Anyway, it's handy info, even though I might not believe Sieverts are the final answer to physiological effects, at least they are closer than some of the older units.

Did you know that NIST (used to be called our National Bureau of Standards) made an alpha particle "microscope beam" that could hit single cell dna and proved hormesis is real? Even on adjacent cells to the ones they hit. Now the question is - how much and so on. That "linear, no threshold" bunk is bunk.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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