Uranium's toxic pathways
The United States Geological Survey (USGS) found radioactive dust several hundred feet from the Kanab North Mine site. The dust contained more than 10 times the background concentration for uranium. Likewise, they found that 15 springs and five wells near uranium mines in the Grand Canyon’s watersheds have dissolved uranium concentrations that exceed safe drinking water standards.
Uranium’s health effects
Science and knowledge about uranium has come a long way since Marie Curie coined the term “radioactivity” in the early 1900s. Uranium was originally feared for its radioactive effect seen after nuclear fallout: think Nagasaki and Hiroshima. Oftentimes, uranium’s effect on the body was not apparent until years after initial exposure. But as time wore on, scientists discovered that uranium can also affect humans through radon gas and fine particle nuclear dust that can cause lung cancer. In addition, uranium can become soluble in water. Radionuclides, or radioactive minerals in uranium-tainted water, gather in the kidneys, possibly causing kidney failure or cancer.
Uranium contamination in Grand Canyon springs
In 1995, David Kreamer, a hydrologist and geoscience professor at the University of Nevada, Las Vegas, and his research group were among the first to measure uranium concentrations in the Grand Canyon’s various springs. His team found elevated levels of uranium in Horn Creek near the Orphan Mine, which had stopped extracting uranium in 1969, over 25 years earlier. Kreamer, among others, feared uranium mining’s effect on water sources for many reasons. Runoff from mining operations can enter the canyon’s springs system, and a majority of springs in and near the canyon discharge or empty at the Redwall-Muav formation. Scientists and geologists have found compelling evidence indicating that the canyon’s springs are connected to the aquifers surrounding the canyon. This connection could spell disaster for the Havasupai people, whose sole source of drinking water comes from the Muav aquifer and impact millions of people who rely on the Colorado River for clean drinking water.