The Health Physics Society website gives some info to help get you started.
Potassium-40 content of the body can be obtained from its natural abundance of 0.0117% of potassium and calculating the specific activity of natural potassium (30.5 Bg/g) using the half life (1.28 x 109 y). The potassium content of the body is 0.2%, so for a 70 kg man the amount of 40K will be about 4.26 kBq.
This source linked from Wiki gives a value of 266,000
40K disintegrations per minute, roughly 4400 per second which is more or less in the same ballpark.
The disintegration energy of
40K is apparently
about 1.35MeV. So the energy released per second in a 70Kg man is
1.35x106 x 4.26x103 = 5.751x109
So roughly 5.75 GeV per second.
The ever-handy
OnlineConversion.com says 5.75GeV is 9.212519475e-10 joule - so we have 9.2x10
-10 Joules per second - i.e. 9.2x10
-10Watts.
So if the decay rate was accelerated a million or even billion fold the heat generated in the body wouldn't be too bad. Kind of disappointing - I hoped it would pan out that Noah would have been nicely cooked from the inside out
Of course, this doesn't mean all that Beta radiation happening inside your body wouldn't be seriously bad for your health. It's too late to work it out now but a quick look at the
dosage levels this would equate to a dangerous level of Sieverts.
Mind you, I haven't done any of these sort of calculations since I left University 26 years ago so there may well be one or more howling mistakes in my working out.
Oops! Wrong Planet