BOULDER, Colo.—Rep. Mark Udall says preliminary tests show federal employees who were exposed to plutonium at a Boulder laboratory aren’t expected to have significant health problems.
Udall said late Thursday that results from more sensitive tests are expected in several weeks.
A vial cracked June 9 at the National Institute of Standards and Technology. About one-quarter gram of powder containing plutonium spilled.
Officials say a few employees had internal plutonium exposure, which can lead to cancer.
Radiation was found in two buildings but officials say no threats to public health or the environment have been identified.
Federal officials have told the lab to stop using radioactive materials until it can show its procedures are safe.
NIST officials also have said trace amounts of the plutonium may have entered Boulder’s sanitary-sewer system when researchers washed their hands after the spill.
After an investigation, NIST estimated that less than 11 percent of the spilled material may have ended up in the system, which is within discharge limits of the Nuclear Regulatory Commission, according to a NIST document released Friday.
