<P> Between 1949 and 1989, over 4,000 uranium mines in the Four Corner region produced more than 225,000,000 tons of uranium ore . This activity affected a large number of Native American nations, including the Laguna, Navajo, Zuni, Southern Ute, Ute Mountain, Hopi, Acoma and other Pueblo cultures . Many of these peoples worked in the mines, mills and processing plants in New Mexico, Arizona, Utah and Colorado . These workers were seldom informed of dangers nor were they given appropriate protective gear . The government, mine owners, scientific, and health communities were all well aware of the hazards of working with radioactive materials at this time . Due to the Cold War demand for increasingly destructive and powerful nuclear weapons, these laborers were both exposed to and brought home large amounts of radiation in the form of dust on their clothing and skin . Epidemiologic studies of the families of these workers have shown increased incidents of radiation - induced cancers, miscarriages, cleft palates and other birth defects . The extent of these genetic effects on indigenous populations and the extent of DNA damage remains to be resolved . </P> <P> After the end of World War II, large uranium deposits were found on and near the Navajo Reservation in the Southwest, and private companies hired many Navajo employees to work the mines . Disregarding the known health risks imposed by exposure to uranium, the private companies and the United States Atomic Energy Commission failed to inform the Navajo workers about the dangers and to regulate the mining to minimize contamination . As more data was collected, they were slow to take appropriate action for the workers . </P> <P> Studies provided data to show that the Navajo mine workers and numerous families on the reservation have suffered high rates of disease from environmental contamination, but for decades, industry and the government failed to regulate or improve conditions, or inform workers of the dangers . As high rates of illness began to occur, workers were often unsuccessful in court cases seeking compensation, and the states at first did not officially recognize radon illness . In 1990 the US Congress passed the Radiation Exposure Compensation Act, to settle such cases and provide needed compensation . </P> <P> In 2008 the US Congress authorized a five - year, multi-agency cleanup of uranium contamination on the Navajo Nation reservation; identification and treatment of contaminated water and structures has been the first priority . Certain water sources have been closed, and numerous contaminated buildings have been taken down . By the summer of 2011, EPA had nearly completed the first major project of removal of 20,000 cubic yards of contaminated earth from the Skyline Mine area . </P>

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