- c . f é/ COPY Aa ik October 1, 1952 Admiral George P. Kraker, Deputy Manager Santa Fe Overations Office 32 998° John C. Bugher, M. D., Director Division of Biology and Medicine, Washington PERMISSIBLE EXPOSURE LEVELS BMBP:WDC This will confirm the telephone call of Dr. Charles L. Dunham to you yesterday authorizing the permissible exposure of 3.9r of gamma radiation for test-site nersonnel, without regard to the rate at which the dose is accumilated, provided this exposure represents the total integrated dose over a period of thirteen (13) consecutive weeks. This permissible exposure is in accord with the authorization for test personnel, as outlined in the memorandum of Dr. Shields Warren to Mr. Carroll Tyler on October 11, 1951. The Advisory Committee for Biology and Medicine, in its meeting of September 12, 1952, approved the use of this permissible exposure for all operations of the Atomic Energy Commission, in-plant as wellas for bomb tests. This authorization, therefore, supersedes my memorandum of July 18, 1952 to Mr. Seth Woodruff approving the exposure of 3,0r over a period of ten (10) weeks. It also corrects the value of 3.0r referred to in Dr. Dunham's teletype to you of September 29, 1952. Should the Test Director consider it desirable to set up somewhat more conservative levels for administrative purposes, particularly EE during actual test periods, that, of course, is his prerogatives Sb , *= a rh “ - sy cc: Dr. Alvin Graves, LASL Ce, oe a7 7 "a Se. Lo “7 ™ . 7. Soe “3, 2s 4 OF S COPY ee %, Py . .