Curious that the Dr. fails to note the difference between professional exposures (adults) and the residents of Kerala, who get their dose from earliest childhood.....
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Jaro
Note: this message is in two parts, due to excessive length.
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EVOLUTIONARY EFFECTS OF NATURAL RADIATION
CBC Radio Transcripts
Sat 09 Nov 2002 12:10:00 ET
QUIRKS AND QUARKS
CBC-R
BOB MCDONALD
DR. PETER FORSTER, Research Fellow in Molecular Genetics,
McDonald Institute, University of Cambridge
BOB MCDONALD: Natural radiation almost seems like an oxymoron, sort of like military intelligence or jumbo shrimp. Concern about radiation for most of us, after all, appeared with the atomic age as we broke into the Pandora's box that gave us nuclear power, the hydrogen bomb and radiation sickness. But humans are much less original than we think. Nature has distributed radioactive substances throughout our environment. They're just usually much less concentrated than the stuff we make for a CANDU reactor. As a result, we're constantly exposed to very low levels of radioactivity. But nature's distribution of radioactivity isn't entirely even. A case in point is a region in the Indian province of Kerala where naturally occurring minerals expose thousands of people to levels of radiation ten times higher than normal. You have to wonder what happens to people who experience exposures like that. Studies so far have shown no obvious health problems for the locals, but Dr. Peter Forster was curious about more subtle effects. Recently he led a team of molecular geneticists to try and figure out exactly what this natural radiation was or wasn't doing to the people who were exposed to it. What they discovered was a disconcerting surprise. Dr. Forster is in the Molecular Genetics Laboratory at the McDonald Institute at the University of Cambridge. Dr. Forster, welcome to Quirks and Quarks.
DR. PETER FORSTER: Hello there.
MCDONALD: First of all, can you tell me about this area in Kerala? What's... what's it like?
FORSTER: Well, I actually don't know much from it, but my wife does because she was born there, and this is how we started off with the idea to do this study. So it's a tropical part of India, and the people who live there are all indigenous. And in coastal Kerala you have a river which washes down radioactive minerals from the mountains and these get accumulated on the beaches. And on these beaches you have a population of fishing folk, several thousand families who have lived there since the beginning of time. And immediately next to this radioactive strip of coastline you have adjacent non-radioactive coastline which is completely normal, as in other parts of the world.
MCDONALD: Now, what is the source of the radiation?
FORSTER: The radiation is caused by a mineral called monazite which contains about ten percent of thorium phosphate. It's so highly concentrated that it's even exploited commercially there.
MCDONALD: Wow. Now, when we're talking about radiation levels, are we talking about normal or... or higher? What... what are we talking about? Can you give me a context there of what kind of levels we're speaking about?
FORSTER: Well, if we take normal radiation levels, we mean about one millisievert. Now, in India we have ten times that amount, about 10 millisieverts.
MCDONALD: So... so what is a millisievert? How... how does that compare to other forms of radiation I might be exposed to?
FORSTER: One millisevert is the dose we get in most areas of the world from natural radiation. If we compare that to artificial radiation we receive, about 0.3 milliseverts would come from, say, X-rays which we receive on average per year.
.....................please see other e-mail, marked "part 2", for continuation.