2 4. To perform routine maintenance on some of the installation's equipment during the month of June, 1979. Summary Report: The first two weeks (13-29 March) were devoted to the repair of the facility on Sand Island which had been damaged by Typhoon Alice. The work performed during this period included the re-building of the tower base whch had been critically undermined when Sand Island was submerged during the typhoon, replacement of one tower anchor and four guy wires, replacement of the portable lab which had been carried approximately 100 yards by the water, re-building of the trace metal facility, building the organic facility, the laying of a new submarine cable to replace the original one which had been damaged beyond repair, re-wiring of the tower and the three support buildings, and the replacement of two deck frames. Between the dates of 30 March-14 April, the sampling apparatus were made ready by the scientific investigators. Actual dry season sampling was begun on 15 April 1979. From that date until 23 May, when the scientific party departed Enewetak, the following samples were collected: 19 High volume air samples, 3 cascade impactor samples, 19 low volume air samples, 3 long dry fallout collections, and several small rain samples, for Texas A & M University for the investigation of anthropogenic organic compounds (e.g., DDT, PCB). 6 Glass fiber filter (GFF) samples for the investigation of particulate matter, 8 GFF plus 2 PUF-PLUG samples for the investigation of particulates and gas phase organics. These samples will be analyzed at the Woods Hole Oceanographic Institution for n-alkalines, fatty acids and fatty and/or polycyclic alcohols. Rainwater was collected for the analysis of formaldehyde, total organic carbon (TOC), and the major inorganic nutrients. 87 separate samples of Hg in air were analyzed for the University of Connecticut, Also a rain sample was collected during one major rain storm. From these collections it will be noted that (1) the major state of Hg in the atmosphere of Enewetak Atoll is gaseous with concentrations between 1-13 x 107 g/m>, (2) particulate Hg is present in concentrations at the 10712 level, (3) chemical speciation experiments designed to establish the chemical forms of Hg in the near surface open ocean atmosphere were conducted, (4) Hg flux determinations in rainfall will be made. Air and rain samples for the further investigation of Pb by the California Institute of Technology group consisted of duplicate samples plus tower blanks for three different periods. Two rain samples of two liters and 100 millileters respectively were collected along with three dry deposition samples. Samples collected for the University of Rhode Island for trace metal (Na, Mg, Al, Fe, etc.) analysis included 14 high volume Whatman 41 filter samples along with 13 blanks, 4 high volume cascade impactor samples along with 4 blanks, 17 low volume 47 mm Nuclepore filter samples with 28 corresponding blanks. For the CFR/CNRS, France group, URI personnel collected the following samples for SEM-EMP analysis of trace metals and also for the analysis of particulate organic carbon (POC), 8 low volume cascade impactor samples and 1 blank, 9 low volume 47 mm Nuclepore filter samples and 9 blanks, 5 high volume