On Jul 12, 2013, at 12:57 PM, Mark van der Woerd <[email protected]> wrote:
> I just re-wrote our safety plan because we have to renew our radiation > license for our new in-house instrument. On this plan, they ask you to write > a worst-case scenario. For an in-house sealed tube instrument, producing CuKa > radiation, we calculated (with the help of the friendly manufacturer, thank > you) that if you had a direct exposure to the beam, for example because your > hand would be in the wrong place at the wrong time, you would burn a 7mm > deep hole in your hand. Interestingly and surprisingly, when compared to our > old rotating anode generator, the estimated worst case scenario for the old > setup was an order of magnitude less severe (less than 1 mm deep burn). The > constant improvement of instruments also makes them just a little more > dangerous. The old days of 'tingle' are long gone and you *really* need to > watch yourself, even on in-house instruments. > > Indeed, if you do not tinker with the safety system and have shielding in > place at all time, as you say, the exposure is never above background. So: > obey all the rules and worry very little. Although I've never knowingly stuck any bodily appendage into an X-ray beam, I recently had the delightful experience of having a skin cancer hacked off my hand. Even though it is hard to know if the cause was an X-ray beam, I've met other crystallographers who have had similarly located lesions, leading me to believe that this might be more common than we tend to acknowledge to ourselves or each other. So I would modify the last quoted sentence to "Obey all the rules and worry anyway." Ionizing radiation, especially when collimated, it a significant hazard, ipso facto.
