Fourteen more radium disposal sites have been discovered by a Department of Energy aerial crew, which wrapped up a week-long helicopter fly-over of Denver late Tuesday.
This brought the total of portentially hazardous sites discovered in the city in the last few weeks to at least 36.
The crew is to return again in two weeks to conduct what is being termed a mop-up operation, flying over areas farther up and down Denver's Platt and Cherry Creek Rivers and over six newly discovered sites each in Boulder County and Colorado Springs.
According to Dr. A1 Hazel of the Colorado Department of Health, positive verification of the newly identified sites must now be made by department of health ground crews. Using a mobile scanning unit on loan from the Environmental Protection Agency, they have been working around the clock to canvass the city at ground level looking for areas where gamma radiation exceeds acceptable limits.
The department has 81 addresses under direct investigation. Emissions at some of the new sites have ranged from 1,000 to 3,000 microroentgens an hour. Normal background radiation typically is 20 to 25 microroentgens.
The first radioactive sites were accidentally discovered several weeks ago, when an EPA official from Las Vegas came across the name of the National Radium Institute while reviewing old mining records. A check of Denver telephone books uncovered a number of other radium refineries that flourished and then were forgotten in the Denver area during the radium boom of the early 1900s.
For nearly 20 years radium was believed to be a cureall for everything from cancer to deafness. Later it became known as a cause of cancer, particularly of bone cancer and leukemia, and capable of producing birth and genetic defects.
More than 100 residents of the city have been tested by the health department, and more are due for medical checkups as a result of the newly discovered sites. Initial testing has turned up negative results, but blood tests, which might give indications of genetic damage, have not returned from the labs.
Hazel estimates that cleanup of the radium-contaminated soil will cost $25,000 per site, but concedes that this amount could escalate dramatically if the soil must be transported out of the state to an authorized disposal facility such as that at Beatty, Nev.
The state is considering collecting the wastes at an existing or inactive uranium mill tailing site. The state already has 17 million tons of uranium mill tailings at inactive, abandoned mills, which produced uranium ore for the military during the 1940s.