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Ruth,
FYI, tritium from the atmospheric
nuclear bomb testing era is now pretty much gone. However, about six
megacuries are "naturally" created each year by cosmic ray spallation of
atmospheric nitrogen. Interesting to note that this source of natural
radioactivity is not generally considered as part of background radiation
exposure because the human dose effect from this "natural" tritium is miniscule.
I imagine that if the six megacuries were
man-made, then it would become a big deal.
Several years ago, as part of a
project I was associated with, I had occasion to study environmental trituium
and produced a few papers on the subject. One of these, titled "The Tritium
Mystique" explored an interesting phenomenon that was noted. Until
the early 1960's, there were hardly any publications in the technical literature
related to the subject of environmental tritium. Then there was a sudden
sharp increase the number of studies. On exploring possible reasons for the
precipitous increase in interest, I could find only one that made any
sense. It was advent of liquid scintillation analysis which allowed for
the relatively simple, sensitive, and precise assessment of
tritium levels in environmental samples. Apparently, there is a tendency by
people to equate delectability with hazard. When we couldn't detect it, we
weren't worried about it. Once it was known to be there, it became a
problem. I wonder whether the fact that
radioactivity is so readily detectable even in minute quantities might, to
some extent, account for the inordinate fears related to
it. Jerry
----- Original Message -----
Now I am totally confused. We have been exposed to tritium (as tritiated water) from atmospheric fallout since the mid-1950s. Since tritium has a 12-year half-life, most of the somatic effects would have been seen by 1990 and any genetic effects would have shown up in those born between 1960 or so and 1990. Has anyone observed any of these in, for example, a population exposed to surface water that would contain fallout tritium as compared to a population drinking well water that would contain much less or none? It seems to me that the primary pathway for tritium to enter the human body is via water, and since all cells require water, tritiated water would not concentrate in any organ. I would be most concentrated in the digestive tract (when you drink it), and carcinogenic effect would be reflected in cancers of the digestive tract. Is my knowledge of physiology, so to speak, all wet? Ruth Ruth Weiner, Ph. D. ruthweiner@aol.com |