Dr Engelbert Buxbaum <[email protected]> wrote in news:[email protected]:
> In article <4c46dc22-1694-45ea-ab11- > [email protected]>, [email protected] > says... >> >> On Jun 8, 10:12 am, "Allan Jones" <[email protected]> wrote: >> > Hi! >> > >> > There is currently a lot of radiation work going on in our lab and >> > i am always worried about people contaminating stuff with small >> > amounts of isotopes the geiger counter does not detect very well >> > (ie tritium, 14c, 35s). >> > >> > Now I have looked into the definition of annual limit on intake and >> > so on and am slightly confused. The ALI values seem extermely high, >> > so does this mean the amounts (a couple of µCi) we use are not >> > particularly dangerous? >> > >> > I do not assume anything is contaminated, but am a worrysome person >> > and some of the people here seem quite relaxed concerning >> > radioactivity. I guess however that back in their days its use was >> > much more common. >> > >> > What do you think? >> >> As a point of comparison, I once had a medical imaging test in which >> I was injected with 5 mCi (yes, that's milli) of radioactive >> thallium. When I got back to lab, they said, ha ha, let's see if >> you're radioactive, and held a geiger counter up to my chest. If >> course, I made the geiger counter chatter, at which point it seemed >> they all backed away and said, "oh." They kept me away from the x-ray >> film for a couple of weeks. > > A colleague of mine had a thyroid scan with Tc, and consequently > blackened out his dosimeter. Created quite a stir with the safety > guys, until the cause was established to be "not work-related". When > he entered the lab, he could make the Geiger-counter needle wrap > around its stop from several meters away. > > A couple of years ago a disgrunteled scientist poored 10 mCi of 32-P > into the coffee urn in the common room at a US university. Widely > published in scientific magazines at the time, but none of the exposed > people suffered any ill effect. > > PET-scans are done with some 200 mCi (sic!) of 18-F (or at least were > some 20 years ago, when I looked into it). Actual treatment of cancers > is yet a completely different game. > > So follow normal safety precautions (ALARA principle), but don't worry > too much. Yes, A colleague revealed a now discontinued practice. This was >35 years ago. We used P32 phosphate, and stored it in a galss tube in the freezer compartment of the fridge next to his desk. He hardly ever wore the badge, since he wasn't using radioactivity <smile>. Harvard radiation safety came in a panic, since the Xrays excited by the P32 electrons from the aluminum around the freezer compartment had blackened the badge. -- Best regards Han email address is invalid _______________________________________________ Methods mailing list [email protected] http://www.bio.net/biomail/listinfo/methods
