Plutonium was detected in about half of the 29 people who were near a June 9 plutonium spill at the Boulder campus of the National Institute of Standards and Technology, agency officials said Thursday.
But none of the employees who received internal exposure is expected to experience any clinically significant health impacts, said Laura Ost, NIST spokeswoman.
Previously, NIST had said a “small number of personnel” were exposed. They did not give an exact number Thursday.
Researchers in the Boulder laboratory broke a vial holding about a quarter-gram of plutonium-containing powder, and some particles spilled.
Officials said radiation was detected in various parts of the building and two sinks, which prompted testing of the Boulder sewer system.
The latest tests, which use a technique called thermal ionization mass spectrometry, were performed by Los Alamos National Laboratory, part of the U.S. Department of Energy National Nuclear Security Administration.
Dr. Edward Cetaruk, a toxicologist with the University of Colorado Denver School of Medicine, said the extremely sensitive tests confirm earlier testing results that showed low levels of exposure.
The TIMS results for six additional people whose samples were received later than the 29 are expected in about a month, according to NIST.
NIST deputy director James Turner said he was heartened by the news.
“We hope having these definitive tests confirm that there are no significant health effects expected will reassure those affected and their families,” Turner said. “Nevertheless, we continue to regret that any exposures occurred. Meanwhile, we are aggressively moving to strengthen NIST’s safety system from top to bottom.”
Howard Pankratz: 303-954-1939 or hpankratz@denverpost.com
