Document emzxy40BY4rKxDRyeZynL4VQ4

\ DEPARTMENT OF H EALTH , ED UCATION . AN D W ELFA RE Public Health Service N A T I O N A L I N ST I T U T E S OF H EA LT H na t iona l in st it u t e o f a r t h r it is a nd met a bol ic d isea ses NATIONAL CANCER INSTITUTE NATIONALINSTITUTE OF RENTAL RESEARCH NATIONAL f^EART INSTITUTE NATIONAL INSTITUTE OF MENTAL HEALTH NATIONAL' MICROBIOLOGICAL INSTITUTE NATIONAL INSTITUTEOF >!lROUDGICAL DISEASES AND BLINDNESS THE CUNICAL CENTER DIVISION OF RESEARCH GFA.NT5 - Box 2537 Fort Douglas Station Salt Lake City 13, Utah July 30, 1956 Dr. Robert A.. Kehoe University of Cincinnati The Kettering Laboratory College of Medicine-- Eden Avenue Cincinnati 19, Ohio Dear Dr. Kehoe: After a lapse of about three years I have again become very much interested in the potentialities of determining: lead-210 in urine. In 1953 you graciously supplied me with some basic information on the absorption and excretion; of lead1which was. very useful. Tie noxir wish to apply this information to develop a test to serve as an index or indirect measure of radon and radon daughter inhalation by uranium miners somewhat as Sulzer and Hursh advocated urinary Po-210 tests. It appears that most of the miners' expo sure is due to.the decay of radon daughters which have been deposited on dust particles suspended in the air they breathe. These daughters rapidly decay to lead-210 in the respiratory passages. Some of this lead might be brought up in mucus and -swallowed, but since each atom originates as a single electrically charged particle, it seems reason able to suppose that most of it reaches the lymph or vascular system fairly rapidly. From here a certain portion winds up deposited in bone, ,and othef portions are excreted in feces and urine. Judging from your data, and assuming a constant exposure, we would expect a plateau, of excretion, to be reached in about six months, after which time there would be a constant relationship between radon plus daughters breathed and urinary or fecal excretion of Pb-210. From your data we have calculated (with some assumptions) that the average adult male when receiving a. relatively constant respiratory intake of lead for over six months will excrete approximately 60)? as much lead per day as he takes in each da)g, and that about %% of the excreted lead m i l appear in the urine. Are these figures in agreement 'with your present data, and how x'eliable should we consider them to be? KE" 0 0 1 9 7 2 9 Dr. Robert A. Kehoe-- 7/30 / 56 -2- ' I am verj grateful xor jour continued assistance in this matter. Sincerelj jours, v'EA:mm K& 0019730