Fallout is radioactive particles that are created after a nuclear explosion. The particles can range in size from smaller than a grain in sand to a small clump of sand. Most of the fallout affects the immediate surrounding area. However, some particles get ejected far into the atmosphere and are spread around the globe where they drift back down to Earth over the course of days, weeks, months, even years. Although these particles may be small, they can cause serious damage. Since they are radioactive, they can cause genetic abnormalities, cancer, and other symptoms of radiation sickness in humans. In large enough doses, fallout can contaminate land to the point of making it uninhabitable for years. An example of this was the US Castle Bravo test in 1954. The US detonated this nuclear bomb in Bikini Atoll in the South Pacific. The fallout was spread to surrounding islands and affected native islanders who had no idea about the test. The US took several days to respond, and by then the islanders had already been affected and their islands contaminated. The islanders were evacuated but still suffered numerous birth defects for years after. In addition, radioactive particles were found as far away as the US and Europe. It seems that in some ways, the fallout is almost more dangerous than the blast