Update: Following a safety review, the National Park Service says it hasn't found any evidence of current uranium exposure at Grand Canyon National Park. In a press release, park officials said that an interagency safety review had indicated that the original radiation readings were overstated, and that current levels are consistent with background radiation in other parts of the park.
Original story: Grand Canyon National Park discovered three five-gallon buckets of radioactive uranium ore near a taxidermy display in the park’s Museum Collection building in March 2018, but failed to disclose their existence, a whistleblowing NPS employee alleged this week.
Though park staff supposedly removed the buckets and their contents from the site in June, the incident did not become public until this month, when Elston “Swede” Stephenson, the park’s safety manager, sent an unofficial email to Park Service employees on Feb. 4. In the email, Stephenson alleged cover-ups by management, and claimed to have been urging Park Service officials to disclose information about the radiation for months.
The Grand Canyon Museum Collection, located in Grand Canyon Village, houses historical, geological, and anthropological artifacts (among other collections) as well as research facilities. The facility hosts children’s tours that stop at the taxidermy exhibit for presentations up to 30 minutes in length. Stephenson said that the uranium had been in the building for 18 years.
It’s unclear, however, what practical effect, if any, the radiation visitors received from the ore could have on their health. In an interview with The Verge, Kathryn Higley, head of the School of Nuclear Science and Engineering at Oregon State University, said radioactivity would have been “zero” five feet away from the buckets of ore, and the likelihood of people receiving dangerous doses from touring or working in the building is “extremely unlikely.”
While Stephenson said that children in close proximity to the ore would have received radiation doses above federal safety standards in a mere 3 seconds, some experts have disputed his claims. Craig Little, a health physicist who worked for Oakridge National Laboratory, told the Arizona Republic that uranium ore primarily emits less-dangerous alpha particles, and could not possibly cause the radiation readings that Stephenson's report cited.
According to the Republic, a park employee’s son discovered the radiation last March when he happened to bring a Geiger counter into the building. Stephenson told the newspaper that the park failed to inform visitors and employees of the potential exposure, despite his insistence.
The National Park Service hadn't responded to a request for comment by the time of publication. In a statement to NPR, a park public affairs specialist said that a recent survey of the building reported radiation at standard levels, but that the Occupational Health and Safety Administration would investigate.
This post was updated on 2/20/2019.