performed on Eastman Kodak EktaChem DT60, DTSC or DTE analyzers. These analyzers provide a wide variety of basic chemistry tests with a small amount of disposable waste. Urinalysis included a dip-stick examination and, when indicated, microscopic analysis. Stool exams were performed on physicians’ request for identification of parasites and occult blood, although the physicians routinely perform a test for occult blood at the time of examination. Roentgenographic services were provided using a dedicated mammographyunit and a standardxray unit manufactured by the Bennett Corporation, Long Island, NY. X-ray interpretation was done at the time of Hospital and Medical Center (Dr. A.B Schneier, Division of Endocrinology and Metaboli Chicago, IL for thyroglobulin analysis; Met of the medical team, the x-ray films were returned to Brookhaven National Laboratory and then referred to a consultant radiologist, Dr. R. Naylor, at the University of Vermont. A portable, battery powered, electrocardiograph machine was available. Electrocardiogram interpretation was done at the time of examination, with a copy often being given to the patient. All electrocardiograms were subsequently returned to Brookhaven National Laboratory and then referred to a consultant cardiologist (Dr. M. Zema) at Brookhaven Memorial Hospital on Long Island, NY, for definitive analysis. In recent years an ultrasound machine (Hewlett Packard Sonos 100) has been available on the ship for assessment of such diverse items as abdominalpain, hematuria,gestational age, and cardiac disease. It is used only whena radiologist or subspecialist physician with expertise in ultrasound examination is part of the team. Ultrasound has been available to confirm findings on physical examination of the thyroid but this requires special planning and an investigator experiencedin thyroid ultrasound. It was not used to screen for subclinical thyroid nodularity. Sera collected during the routine physical examinations were analyzed at the time of patient examination, as clinically indicated. The remainder was frozen for further testing upon return to Brookhaven National Laboratory. The latter tests were performed at the Brookhaven Clinical Laboratory or referred to university and commercial laboratories. Among the referral laboratories were: Hazelton Washington, Inc., hematology analyzer. The chemistry analyzqr is calibrated prior to each mission, and bi-level q control samples are run on all analpses. examination, However, if no radiologist was part Vienna, VA, for hormone assays; Michael Reese Honolulu, HI; and Smith Kline Bio-Science, Ki Prussia, PA. Pathologists’ Laboratories, In involves routine calibration, maintenance fand monitoring of all instrumentation. Daily tri- performed in the field are re-analyze Brookhaven National Laboratory to compare and to confirm the earlier results all of proved to be within acceptable tolerance. as Other quality assurance methodsinclude t of questionnaires given to patients. questionnaires, translated into Marshallese, wi responses being interpreted at the present ti important quality assurance mechanism i involvementof volunteer physicians from arou United States, for this rotation through the pr program attuned to neweror better approaclfes to diagnosis and management. In additioh to information obtained by personal interaction during the missions, ideas for bettering the program are requested via a questionnaire distributed Finally, the results of these and other mech of quality assurance are reviewed byg the Brookhaven National Laboratory Clinical Research