Health Editor’s Note: Having been a visitor to the Grand Canyon as recently as August of 2018, can I mention how happy I am that we did not visit the Grand Canyon National Park’s museum collection building?. Not one, not two, but three 5 gallon buckets full of naturally occurring uranium ore just sitting there for almost 20 years. What were they thinking?… ..Carol
Huge Open Buckets of Uranium Ore Found at Grand Cannon? Totally Fine, Experts Say.
by Brandon Specktor, Senior Writer for Live Science
For nearly 20 years, a trio of 5-gallon (19 liters) paint buckets sat near the taxidermy exhibit at Grand Canyon National Park‘s museum collections building. Those buckets, it turns out, weren’t holding paint — they were actually loaded up with uranium ore, a naturally occurring rock rich in uranium that gives off potentially dangerous radiation.
Elston “Swede” Stephenson, a health and wellness manager at the park’s South Rim, recently described the uranium find and subsequent “cover-up” in a series of email blasts to Congress, his fellow National Park Service employees and the staff of The Arizona Republic newspaper. [Soviets Hid Nuclear Bunkers in Poland’s Forests (Photos)]
Stephenson warned that thousands of employees, tourists and school groups who visited the exhibit between 2000 and 2018 were likely “exposed” to dangerous amounts of radiation, especially groups of kids who sat for 30-minute presentations in the uranium’s vicinity. These children may have been exposed to roughly 1,400 times the safe radiation dosage allowed by the Nuclear Regulatory Commission, Stephenson wrote. Scary stuff, if true.
However, several experts told Live Science that Stephenson’s assessment may be unfounded.
“If the time spent near the ore was short, there is likely little cause for concern,” Bill Field, a professor of Occupational and Environmental Health at the University of Iowa, told Live Science in an email.
The danger, if any, from the Grand Canyon ore buckets depends on a long list of factors, Whicker said, including an individual’s distance from the ore, the length of their exposure, the quantity of ore in the buckets, the amount of uranium in that ore, and the amount of shielding provided by the rocky parts of the ore itself and the container.
In this case, the plastic paint buckets may have provided a powerful enough shield against the ore’s radiation. Modi Wetzler, a chemistry professor at Clemson University who studies nuclear waste told The Arizona Republic that, while gamma rays can be dangerous if inhaled, they are easily absorbed and rendered harmless by just a few inches of air, or even a person’s outer layer of dead skin.
The ore’s relative harmlessness is reflected in a report from the Parks Service, which Stephenson referenced in his emails.
After a teenager with a Geiger counter accidentally discovered the ore buckets in the museum in March 2018, the Parks Service launched a brief investigation to test radiation levels in and around the building. According to their report (which Stephenson quoted to The Arizona Republic), direct contact with the ore resulted in radiation levels at roughly twice the safe annual dosage allowed by the Nuclear Regulatory Commission — however, readings taken just 5 feet (1.5 meters) away from the bucket showed zero radiation.
The next steps
The uranium ore has since been disposed of in a nearby uranium mine. Meanwhile, the Parks Service, the U.S. Occupational Safety and Health Administration and the Arizona Bureau of Radiation Control are now investigating the museum and its premises. According to Emily Davis, Grand Canyon National Park Public Affairs Officer, radiation levels at the site are normal and safe.
“A recent survey of the Grand Canyon National Park’s museum collection facility found radiation levels at background levels — the amount always present in the environment — and below levels of concern for public health and safety,” Davis told NPR. “There is no current risk to the public or park employees. The museum collection facility is open and work routines have continued as normal.”
Any long-term effects caused by the ore’s 18-year stint in the museum remain to be identified. While it might be negligible, the ore likely did increase the radon levels in the building somewhat, Field told Live Science.
“The facility should have radon testing performed,” Field said. “Over the long term, however, the potential exposure from radon from natural sources in the soil and rock under the facility would likely be the greatest source of radiation to the public and workers.”
Stephenson did not immediately respond to Live Science’s request for comment.