According to the US EPA:
(November 2011) Note that is necrosis of the jaw. Necrosis is tissue death.
While this is from a document about mining, exposure or potential exposure doesn’t end with mining but is a major problem for uranium milling, uranium conversion to uranium hexafluoride, uranium enrichment, as well as nuclear waste from nuclear power stations. Dust from tailings and abandoned uranium mines is a problem, as well. Furthermore, the document goes on to point out that “From 1944 to 1986, the extraction of nearly four million tons of uranium ore occurred on Navajo lands in Arizona, New Mexico, and Utah. Today the mines are closed, but a legacy of uranium contamination remains from more than 500 abandoned uranium mines, homes built with contaminated mine waste rock, and contaminated water wells“.
There are many more abandoned uranium mines: “The EPA’s ULD has information for approximately 15,000 [uranium] mines, while the DOE mine database has 4,225 mines. Some of the higher numbers in the EPA data set are attributed to the EPA’s listing of mine features (waste-rock piles, adits, pits, etc.) as separate sites or records, compared to DOE’s approach that these are ancillary features of one mine….
It is important to remember that the actual size and number of features can vary greatly… a large amount of overburden may have been removed and only a small deposit was mined, resulting in a large amount of waste rock for a mine in the Small production-size category.” http://www.lm.doe.gov/WorkArea/DownloadAsset.aspx?id=10676
(Defense-Related Uranium Mines Location and Status Topic Report, Final , August 2014 )
While we are told that there are 500 abandoned mines on Navajo Land
“Approximately $985 million will be paid to U.S. EPA to fund the clean-up of approximately 50 abandoned uranium mines in and around the Navajo Nation, where radioactive waste remains from Kerr-McGee mining operations. Additionally, the Navajo Nation will receive more than $43 million to address radioactive waste left at the former Kerr-McGee uranium mill in Shiprock, N.M.” https://miningawareness.wordpress.com/2014/11/12/anadarko-5-billion-settlement-toward-clean-up-of-kerr-mcgee-nuclear-uranium-mines-creosote-and-other-cleanup-sites/
See more at the web site: http://www.cleanupthemines.org