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. Roentgenographicservices were provided using a dedicated mammography unit and a standard xray unit manufactured by the Bennett Corporation, Long Island, NY. X-ray interpretation was done at the time of examination. However, if no radiologist was part of the medical team,the x-rayfilms 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 abdominal pain, hematuria, gestational age, and cardiac disease. It is used only when 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., Vienna, VA, for hormone assays; Michael Reese Hospital and Medical Center (Dr. A.B Schneider, Division of Endocrinology and Metabolism), Chicago, IL for thyroglobulin analysis; MetPath, Teterboro, NJ; Smith Kline Beecham (Accupath), Honolulu, HI; and Smith Kline Bio-Science, King of Prussia, PA. Pathologists’ Laboratories, Inc. in Aiea, HI, was the primary source for Papanicolaou smear and cytology interpretations. Quality control/quality assurance is an important focus of the medical program. Accreditation by the Joint Commission on Accreditation of Healthcare Organizations is one manifestation of this. In the laboratory quality control and quality assurance involves routine calibration, maintenance and monitoring of all instrumentation. Daily tri-level analysis of reference materials is performed on the hematology analyzer. The chemistry analyzer is calibrated prior to each mission, andbi-level quality control samples are run on all analyses. Approximately 10 percent of all chemistry tests performed in the field are re-analyzed at Brookhaven National Laboratory to compare with and to confirm the earlier results all of which proved to be within acceptable tolerance. When necessary, laboratory instrumentation is inspected and repaired by company service representatives. Other instrumentation, such as sphygmomanometers, electrocardiograph machines, doppler units, are periodically calibrated and have routine preventative maintenance performed at Brookhaven National Laboratory between missions. Other quality assurance methods include the use of questionnaires given to patients. These questionnaires, translated into Marshallese, with the responses being interpreted at the present time by Mr.Alfred Capelle, Director of the Marshall Islands Alele Museum in the Republic of the Marshall Islands in Majuro, solicit criticism and advice for improving the medical program’s operation. One important quality assurance mechanism is the involvementof volunteer physicians from around the United States, for this rotation through the program of new medical eyes and ears keeps the medical program attuned to neweror better approaches to diagnosis and management. In addition to information obtained by personal interaction during the missions, ideas for bettering the program are requested via a questionnaire distributed to all professional personnel at the end of cach mission. Finally, the results of these and other mechanisms of quality assurance are reviewed by the Brookhaven National Laboratory Clinical Research