SESSION IV MILLER: 203 Dr. Donaldson, what is the minimum study that would reveal in other organisms than man that the radiation had taken place? What is the minimum study that will reveal evidence of radiation exposure? DONALDSON: I don't know the answer to that question, CONARD: I was talking to a botanist and he thought it would be worthwhile to study some of the pollen from the coconut trees on some of the atolls, and he thought, I believe, by chromosomai aberrations that he could detect persisting radiation damage. I would think that this would be a fairly simple study that could be done. MILLER: But it hasn't been. CONARD: Maybe Schull might have something to add. SCHULL: If memory serves mé correctly, the Indians have examined the palm trees growing in the Chavara- Needakara area of Kerala to see whether they exhibited a higher frequency of chromosomal abnormalities, presumably ascribavule to the higher levels of radiation encountered in this area. The results were somewhat ambiguous, I believe. There are, so far as we now know, no unique yardsticks of radiation damage of a genetic nature, and the crux of any study becomes the demonstration of a dose dependence. If there is no variability in doses, or the variability is so small as to preclude even ordering the exposures, it is difficult, indeed, to demon- strate a radiation effect. There's a Japanese observation that I believe is relevant to the question that Dr. Taylor asked. In 194% or 1950—probably 1950— Yamashita Kosuke, a geneticist at Kyoto University, undertook a fairly extensive study in Hiroshima of the distribution of abnormal forms of Veronica persica, a common garden flower. His data, published in 1956 (Reference 41), revealed a definite correlation between the frequency of aberrant forms of this plant and distance from ground zero, Atypical forms diminished with increasing distance from the hypocenter, _ ‘ TAYLOR: Just looking at people's gardens? SCHULL: Essentially that. In Japan, Veronica grows along the roadside in many areas, or did then. The aberrant forms Yamashita