>So if you keep the source for a day in your pocket, you reach the limit of radiation of a radiation worker
You're missing the part where 2 millisieverts / hour is the dose at a distance of 1 meter. If you put in your pocket, you would rapidly sustain radiation burns.
You're also missing that a dose sustained over a short period is much more deadly than a dose dragged out over a year. In the latter case, the body will be repairing the damage as it happens, mitigating the effect.
Where did you get the distancie of 1 meter? It's very hard to get any data from the press.
I think you are right. Let's make some back of the envelope calculations.
The frontal surface of a person is 1m^2 approximately. The surface of a sphere of 1m is 4/3*pi*(1m)^2 ~= 4m^2. The silly proportion is 2msV/1m^2*4m^2 = 8mSv, but 1m is not far enough to assume the sphere is almost flat. Let's duplicate it to 16mSv (8 idiots can form a round at 1m, shoulder to shoulder and absorb almost all the radiation). May I round it to 20 mSv?
If someone put it in the pocket, s/he will get half of the radiation, that is 10mSv/hour. [Before you find more errors in my comment, I agree that it's more complicated. The front pockets of the pants are probably the worst area. Holding it in a closed hand would double the radiation. Anyway, if you have a more accurate calculation, it is welcome.]
A Chest CT scan is 7mSv and it takes like half an hour, but it's more evenly distributed.
My guess is that you can get some nasty radioactive burns as warned in the press article, but in a short time it's not lethal as clamed by the GP.
The risk with radiation sources dramatically increases within 1 m – we can calculate the dose rate using the ‘inverse square law’:
At 1 cm, the dose rate will be 10,000 time higher …. 16,650 mSv/h (or 16.65 Sv/h)
At 1mm (ie, if you were to pick the source up with your fingers), the dose rate would be 1,665 Sv/h – this will cause some serious damage to your fingers and surrounding tissues.
>>>
I'm a little suspicious of their inverse-square calculation, though, as by their logic the dose rate would be infinite at a distance of 0m (skin contact). That's clearly not the case.
Thanks for the link. It looks like the get the official data at 1m and decided to extrapolate, but those calculations don't make any sense. The inverse square law is only a good approximation when the source and the target are small (or other special configurations, for example when one of them is a sphere).
You're missing the part where 2 millisieverts / hour is the dose at a distance of 1 meter. If you put in your pocket, you would rapidly sustain radiation burns.
You're also missing that a dose sustained over a short period is much more deadly than a dose dragged out over a year. In the latter case, the body will be repairing the damage as it happens, mitigating the effect.