In Dine (the language of the Navajo people, who are sometimes called the Dineh), they call Uranium “Leetso” which means The Yellow Monster.

Navajo President Joe Shirley, Jr., appreciates council delegate's letter to
Speaker Morgan stating special session would be costly, unneeded
WINDOW ROCK, Ariz.- Navajo Nation President Joe Shirley, Jr., on Wednesday
asked a U.S. Senate committee to respect Navajo sovereignty and to uphold
the 2005 Navajo prohibition on uranium mining.

Testifying before the Senate Committee on Energy & Natural Resources,
President Shirley said the Navajo people have suffered through a traumatic
and tragic experience of illness and death resulting from uranium mining
from the 1940s until the 1970s, and they did not wish to repeat it - or be
forced to by uranium mining companies who now want to return to Navajoland.

"The Navajo people do not want renewed uranium mining on or near the Navajo
Nation," President Shirley said. "I ask you to respect the Diné Natural
Resources Protection Act that places a moratorium on Navajo land and within
Navajo Indian Country."

The President said the Nation would use "any and all measures" to fight the
return of uranium mining to its land. Speaking forcefully, he said he is
unwilling to risk the health, safety and welfare of his people against the
promise that the proposed in situ leach mining process will keep them, their
land and their water safe and free of more radioactive contamination.

"I will not risk the health and safety of my people on the promises of those
who advance as a fact something for which there is little evidence," he
said. "I will not allow my Navajo people to be the guinea pigs of those
seeking only profit. I will not sit idly by and watch as another generation
of Navajos face a litany of cancers and other illnesses."

“…This thing called uranium is dangerous. That is what it is called. If inhaled, it will affect you inside. You have to be aware of the danger. I am sure there is good money in the work, but if you compare life with money, money is nothing. It is not worth much, is how I think. The Five-Fingered People, humanity, is priceless. If there is something to be remembered – it is better not to work with uranium.”

From an interview with former Uranium miner George Tutt.

"In one of the stories the Navajos tell about their origin, the Dineh (the people) emerged from the third world into the fourth and present world and were given a choice. They were told to choose between two yellow powders. One was yellow dust from the rocks, and the other was corn pollen. The Dineh chose corn pollen, and the gods nodded in assent. They also issued a warning. Having chosen the corn pollen, the Navajo [people] were to leave the yellow dust in the ground. If it was ever removed, it would bring evil"

“The action of pumping dissolved oxygen and sodium bicarbonate into the rocks, the in situ leachate (ISL) method, causes that uranium concentration to increase almost 100,000 times. So you go from very high-quality, pristine water, and you make it a toxic soup. Nobody could drink it. So the company has to make sure that none of that stuff escapes, because it’s a poison. Because the underground streambeds are narrower than the distance between the monitor wells, our fear is that a leakage of the mining fluids will escape, go past those monitor wells, and never be detected.”

From interview with Navajo activist Chris Shuey, of SRIC.

The Navajo suffered radiation poisoning due to government sponsored Uranium mining in Arizona and Colorado from the 1940s. Congress enacted the Radiation Exposure Compensation Act of 1990 which was amended in 200[5] to compensate some Uranium miners who were poisoned due to unsafe working conditions in the mines.