WASHINGTON (CN) – Radium contamination at over 65 sites in the area of Denver, Colo. has been sufficiently cleaned-up to remove these sites from the National Priorities List of Superfund hazardous waste sites, according to a delisting notice from the Environmental Protection Agency.
From 1898, when Madam Cure discovered radium until the late 1920’s, when radium was discovered in the Belgian Congo, the radioactive ore containing radium, called pitchblende, was dug up from mines on the Denver Plateau.
Radium was not processed from Pitchblende in the U.S. until 1914 when, fearing that a European war would interfere with domestic radium supplies, the U.S. Bureau of Mines open the National Radium Institute in cooperation with a private company, to process radium.
After closing in the late 1920’s, the Institute was largely forgotten and the trail of the 1,500 tons of radioactive ore processed in its facility was lost until the EPA found references to the Institute’s history in a 1916 Bureau of Mines report. The agency eventually identified more than 65 sites in and around metropolitan Denver that were affiliated with the Institute.
The properties were identified as the Denver Radium site and placed on the Superfund clean-up list in 1983. The main threat posed by radium is the buildup of the radon gas it emits in structures built over contaminated sites. Chronic exposure to radon has been show to cause lung cancer.
Clean up at most of the sites consisted of excavation and removal of contaminated materials to a disposal facility in Utah. One location, the Shattuck Chemical Company had significant contamination, and even after removal of contaminated dirt and fill the agency will leave the site on the Superfund list, as concerns about ground water contamination remain.
The original site of the National Radium Institute was used as a brick manufacturing facility until the early 1980’s and, following clean-up, has been redeveloped for big box retail development including a Home Depot.
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