Re: OT: Chernobyl radioactivity (was Re: booze words
|From:||Lars Finsen <lars.finsen@...>|
|Date:||Sunday, May 11, 2008, 23:53|
Den 12. mai. 2008 kl. 01.02 skreiv MorphemeAddict@WMCONNECT.COM:
> The half-lives of strontium-90 and cesium-137 are 28.8 and 30.23
> respectively. Both act like other elements (strontium like calcium
> and cesium like potassium) which are readily incorporated into
> tissues, where they remain and propagate up the food chain.
Strontium is the most dangerous, because it is incorporated into
bone, where it remains. Cesium accumulates in soft tissue, but will
slowly trickle out again through the urine.
> They won't be negligible for generations, if not centuries.
> Where do you think these radioactive isotopes are washed out to? The
They are washed out by rain from the soil. Eventually they end up in
the sea (where they may re-enter the food-chain, of course). In
addition to their radioactive half-lives, such pollutions also have a
washing-out half-life which varies with the nature of the soil and
with the climate. It's more effective here in the west where it rains
a lot. Since cesium ions are much more soluble in water, I would
expect cesium to have a much shorter washing-out half-life. (I don't
have the exact figures, but they can be found out easily I think if
you are interested.) Anyhow, mushrooms here aren't free from
radioactivity, but nowadays I don't think they are significantly more
radioactive than other foodstuffs.