Korea) combined. These nuclear tests infused vast quantities of radioactive material into the world's atmosphere, which was widely dispersed and then deposited as global fallout. How downwinders are exposed to fallout Aboveground nuclear explosions produce a characteristic mushroom cloud, which moves downwind as it reaches its stabilization height. Dispersion of the radioactive elements causes vertical and lateral cloud movement, spreading radioactive materials over adjacent regions. While the large particles settle nearby the site of the detonation, smaller particles and gases may be dispersed around the world. Additionally, some explosions injected radioactive material into the stratosphere, more than 10 kilometers above ground level, meaning it may float there for years before being subsequently deposited uniformly around the earth. Global fallout is the result, which exposes everything to an elevated level of man-made background radiation. While "downwinders" refers to those who live and work closest to the explosion site and are thus most acutely affected, there is a global effect of increased health risks due to ionizing radiation in the atmosphere. Health effects of nuclear testing The earliest concerns raised about the health effects of exposure to nuclear fallout had to do with fears of genetic alterations that may occur among the offspring of those most exposed. However, the observed inheritable effects of radiation exposure by groups with histories of acute risk are considered minimal compared with the significant increase in thyroid cancer, leukemia and certain solid tumors that have developed within a decade or more after exposure. As studies of biological samples (including bone, thyroid glands and other tissues) have been undertaken, it has become increasingly clear that specific radionuclides in fallout are implicated in fallout-related cancers and other late effects. Ionizing radiation contained in fallout from nuclear testing is especially damaging to dividing cells. For this reason, fetuses and infants are especially vulnerable to injury. Such cellular damage may later manifest as leukemia and other cancers in children. In 1958, the United Nations Scientific Committee on the Effects of Atomic Radiation reported on fetal and infant deaths caused by radiation. In 1980, American popular weekly magazine People reported that from about 220 cast and crew who filmed in a 1956 movie, The Conqueror, on location near St. George, Utah, ninety-one had come down with cancer, and 50 had died of cancer. Of these, forty-six had died of cancer by 1980. Among the cancer deaths were John Wayne, Pedro Armendáriz and