, EISENBUD: 205 One problem that's cropped up in Brazil which haen't been solved and that might be pertinent here is the fact that it's hard to tell where these chromosomal aberrations come from. You take a sample of a plant and it's easy to calculate the somatic dose because presumably th2 piant has been there foz its life. But what the dose is at the genotype of that plant is very hard to calculate because it goes back presumably many thousands of years, and maybe this plant came from a seed which was dropped by a bird two months ago and picked up ten miles away. I suppose to some extent this would be true in Rongelap where your coconuts tend to drift around, I don't know what tne mean distance traversed by a cosmos pollen is, but this would even have to be consicered in Hiroshima. In Hiroshima it certainly must be a large distance in relation to the radiation gradient in Hiroshima over a 10-year period. WARREN: Looking at acria!l photographs of this Brazil site, though, you don't see any change in the foliage when you come over the rolling country up to the edge of this. EISENBUD: There are differences in the radioactivity partly due to the fact that there are also chemical changes associated with the mountains, which in turn give risé to the fact that it's radioactive. These chemical changes presurnably are important. This is another factor that has to be considered. WARREN: Is that a volcanic cone or this... EISENBUD: It's a volcanic cane with an alkaline intrusion in the center, The alkaline intrusion is where the main radioactivity is about a couple of kilometers across, about 300 meters high, above... WOLFE: Is it active? EISENBUD: It was many, many thousands of years ago but not in historic times. This was a major volcanic eruption. The cone is about 50 kilometers in diameter. Within the center of it is an alkaline intrusion which is just a-knob which brought up a lot of rare earth minerals associated with thorium. This is a few kilometers across and is where the work is going on. WOLFE: I haven't seen it. WARREN: I've only read about it. You don’t run sheep on this be- cause there's no grass or not enough foliage? a SESSION IV