Off-Site Monitoring Off-site monitoring stations were located on populated islands out to a distance of about 1,000 miles from the test zone. Samples of soil, vegetation, fruits, water and marine life were collected before testing began and repeated sampling was conducted during and after testing ceased, to determine the background levels of radioactivity in the area and to determine whether there were increased levels in the same area resulting from the test series. Environmental Safety During Operation Dominic (1962) there were 34 nuclear detonations above the Pacific Ocean near Christmas and Johnston Islands. The ex- plosive yields of these devices ranged from low kiloton into the megaton range in TNI equivalent. The height of burst for each detonation was sufficient to negate local radioactive fallout. The devices were delivered to the point of detonation by either manned aircraft or by surface-to-air missiles. In addition to the atmospheric tests, there was one underwater test of a low yield nuclear device detonated in the Eastern Pacific Ocean several hundred miles from the closest land area. Essentially all the radioactive fission products produced by this test were deposited in the ocean and were soon dispersed and diluted to concentrations which were of no significant biological hazard to man or marine life. All nuclear events at Christmas Island were detonations of devices released from manned aircraft. These bursts occurred over water and