Document N2jEzV0mpbZYLNOgyn5R7Kqzg

THE UNIVERSITY OF BRITISH COLUMBIA VANCOUVER 8, CANADA DEPARTMENT o f g e o l o g y May 5, 1965. Dr. Robert A. Kehoe, M.D., Director, Department of Preventive Medicine and Industrial Health, University of Cincinnati, Eden Avenue, Cincinnati 19, Ohio. Dear Dr. Kehoe: Marking and dealing with our Spring examinations has prevented me from replying before now to your most welcome letter of April 12th. You ask me whether I have seen the reports of C.C.Patterson. I have seen two or three of his papers, and naturally, as a geologist, have found them very interesting. However, before drawing any conclusions as to the possible significance from a health point of 'view, I feel it would be essential to follow up some of the work on lead described recently by Sir Ernest Marsden,{"Nature", Jtily 18th, 1961; - "Incidence and Possible Significance of Inhaled or Ingested Polonium"). /" ' Sir Ernest draws attention to the fact that lead can occur in various forms, and that whether we are dealing with lead in tobacco or in tetra-ethyl lead, the proportion of Lead 210 present may assume seme significance. Such evidence as Sir Ernest has already collected suggests that tobaccos with a high Lead 210, and hence a significant amount of Polonium 210, may be far more dangerous healthwise than other tobaccos much lower in Lead 210. We have just got to the point of looking at some foods and findin!:: that there are wide variations in the amount of alpha particles emitted. I presume the next step will be to determine how much tetra-ethyl lead carries Lead 210 in abnormal amounts. However, as you say, there are so many things to do, and so much to learn, that one must be cautious in making any rash conclusions. As I think you, yourself, must realize by now, we look upon ourselves, not as crusaders for a particular point of view, but as seekers after facts. We have never hesitated to disseminate the facts, and, although we have from time to time suggested some conclusions which might arise from these facts, we have always tried to draw a sharp line between hypothesis and facts. May I say that we hope that yoir retirement will not mean an end to our correspondence. I would like very much to visit you, but that seems a most unlikely Dr. Robert A. Kahoe, M.D 2 May 5, 1965 possibility at the present time because the University I have the privilege of working for is unable to give very much encouragement to her staff members to go wandering around the Continent. Did you see our latest contribution in the April 23rd issue of "Science"? I would very much appreciate your reaction to that article. Kindest regards. Yours sincerely, ' {/ / ' W iX- ' PFyrnoffoecscsnorr, DVkaevp'i OaTr*tf.mTvueayn4t- ro\-Pf {Geology HVW/w. Dictated but not read.