The University of Tulsa is working to clean up what it is calling a minor spill of a radioactive chemical on its research campus and is having 21 people who may have been exposed to the cesium-137 undergo medical checks, school officials said on Tuesday.
The spill by Tracerco, a subsidiary of British chemical company Johnson Matthey that was contracted by the university, is believed to have occurred last fall but Tracerco did not notify the school about it until Aug. 25, the university said.
Tracerco spilled a small quantity of cesium-137, a radioactive isotope often used in research, in a restricted building on a campus that houses research equipment, according to Steadman Upham, the university's president.
The cesium-137 was being used for research on a joint industry project managed by the petroleum engineering department, the university said. The level of radiation from the spill, thought to be around the volume of a teaspoon, is currently unknown, school officials said.
The cleanup involves setting up a perimeter around an area where radiation is no longer detected and then physically removing material inside the perimeter, said Scott Holmstrom, an associate professor at the university in the Department of Physics & Engineering Physics.
"One of the simplest methods for removal is the same as when you want to remove lint from clothing; you use tape or a sticky roller," he said.
The university found that 21 people were at risk for exposure and it is having those people evaluated by medical experts, the school said.
People routinely are exposed to very small amounts of cesium-137 in soil and water, but higher levels of exposure can increase the risk of cancer, according to the U.S. Environmental Protection Agency.
After being notified of the spill, the university immediately restricted access to the building and contacted the Oklahoma Department of Environmental Quality, which has since inspected the site and the surrounding areas, said Mona Chamberlin, spokeswoman for the school.
Tracerco officials were not immediately available for comment.