Downwinders were individuals and communities in the intermountain area between the Cascade and Rocky Mountain ranges primarily in Arizona, Nevada, New Mexico and Utah but also in Oregon, Washington, and Idaho who were exposed to radioactive contamination or nuclear fallout from atmospheric or underground nuclear weapons testing, and nuclear accidents. More generally, the term can also include those communities and individuals who are exposed to ionizing radiation and other emissions due to the regular production and maintenance of coal ash, nuclear weapons, nuclear power, nuclear waste and geothermal energy. In regions near U.S. nuclear sites, downwinders may be exposed to releases of radioactive materials into the environment that contaminate their groundwater systems, food chains, and the air they breathe. Some downwinders may have suffered acute exposure due to their involvement in uranium mining and nuclear experimentation. Several severe adverse health effects, such as an increased incidence of cancers, thyroid diseases, CNS neoplasms, and possibly female reproductive cancers that could lead to congenital malformations have been observed in Hanford "downwind" communities exposed to nuclear fallout and radioactive contamination. The impact of nuclear contamination on an individual is generally estimated as the result of the dose of radiation received and the duration of exposure, using the linear no-threshold model (LNT). Sex, age, race, culture, occupation, class, location, and simultaneous exposure to additional environmental toxins are also significant, but often overlooked, factors that contribute to the health effects on a particular "downwind" community. Nuclear testing Between 1945 and 1980, the United States, the U.S.S.R., the United Kingdom, France and China exploded 504 nuclear devices in atmospheric tests at thirteen primary sites yielding the explosive equivalent of 440 megatons of TNT. Of these atmospheric tests, 330 were conducted by the United States. Accounting for all types of nuclear tests, official counts show that the United States has conducted 1,054 nuclear weapons tests to date, involving at least 1,151 nuclear devices, most of which occurred at Nevada Test Site and the Pacific Proving Grounds in the Marshall Islands, with ten other tests taking place at various locations in the United States, including Alaska, Colorado, Mississippi, and New Mexico. There have been an estimated 2,000 nuclear tests conducted worldwide; the number of nuclear tests conducted by the United States alone is currently more than the sum of nuclear testing done by all other known nuclear states (the USSR, Great Britain, France, China, India, Pakistan, and North