With the exception af the development ob shin Jesions vind eplhilion, plyscac al oatoainatians atmo tine revealed findings in cay group Chat could be attributed with certumts to cadiathon The various clintead conditions encountered In the most severely exposed proups were not re - markably different frm those seen in the least exposed Utirth group epilation appeared about the f2th to 14th post-exposure days. 2.3 Phe skin lesious and CLINICAL OBSERVATION AND THERAPY AS RELATED TO HEMATOLOGICAL, FINDINGS Although detailed hematological findings are presented in chapter 4, certain considerations Of the relatron of clianreal to hematological (indings are discussed here. Lub Leukocyte Counts Between the $3rd and 43rd post-exposure days, LO per cent of the Rongelap tndaviduals reached wan absolute yramidocyte level of L000 per cubie miftimeter oc below. ‘The lowest count observed duriag: this period was 700 granulocytes. Durtag Chis taterval the advisability of pay - ing prophylactie antibioie therapy to such idividuals was carefally cecoustde red. However, prophylactic antibiotics were not instituted because of the foliowlnpe conside ca thans: (1) All individuals were under continuous medicul observation so that tibection would be discovered in its earhest stages. (2) Since sume individuals might require antibiotics for long periods of time if infection occurred, the premature administration of such drugs would not only possibly obscure medical indication of treatment, but might potentially lead to the development of drug resistant organisms in an individual with an already lowered resistance to infection. (3) There is no accurate knowledge of the number of grarulocytes required by nian to prevent the types of infection seen in agranulocytosis. (4) The observed situation was not strictly comparable to agranulocytosis with an aplastic marrow due to potentiaily lethal doses of radiation. In the latter instance, yranulocytes fall rapidly and there are practically none in the circulation wher infection oceurs. In the present group of individuals exposed to radiation, although most counts were approximately one-fourth of normal, the fall to that level was gradual and there was some evidence of granulocyte regenecation. White counts were repeated at three or four day intervals on all of the exposed individuals and more frequently on those with the lowest counts. Those with symptoms or elevated temperatures were treated only after an attempt to establish a diagnosis was made, even if a period of observation was necessary. During the observation period, the patients were examined at frequent intervals and the temperature checked every few hours. ‘Twenty-seven individuals had total leukocyte counts of 4000 or below or absolute neu~ Crophile counts of 2500 or less af some time during the period of observabion. Ot (hese 27, 13 had symptoms of disease that required evaluation for possible antibiotic therapy. Eleven of the 13 had severe upper respiratory infections, one individua) had abdominal pains and fever, and one had urticaria (hives) with fever. The incidence and type of symptonis in the group with low leukocyte counts did not differ materially from those in the remainder of the population and it appeared that the occurrence of disease and the presence of leukopenia was coincidental. The 13 instances in which it was necessary to consider the use of antibiotic therapy in neutropenic individuals are summarized below: Elevenof the 13 individuals had severe upper respiratory infections. Eight uf these had malaise, sore throat, nasal discharge, and temperatures that varied between 99 and 101.4°F and then fell to normat within a 12 hour period. Since the response of this group to upper respira‘ tory infection appeared identical with that of individuals without neutropenia, no therapy was given. Two of the 11 had marked malaise, headache, abdominal pain, nausea, diarrhea, and high fever. Both were children, one age seven, the other age two. In both instances, the symptoms were out of proportion to the physical findings, which were negative except for head colds and mild pharyngeal injection. The seven-year old child had a temperature of 102.6 when first seen 25