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. _______________________________________________ Methods mailing list [email protected] http://www.bio.net/biomail/listinfo/methods
