A Department of Energy (DOE) aerial measuring system response team arrived in Denver today to begin a week-long helicopter search for radioactive dumpsites in 20 square miles of the city.

The aerial search is an expansion of a survey in six states to determine if radiation contamination from 50- to 60-year-old radium dump sites pose a health risk to hundreds of people who unknowingly built homes on businesses upon these sites.

"This is more than we usually do," says L. J. Deal of the DOE's operational environmental safety division, "but we think it's proper to assist [the state] as much as we can."

Radium is a known cause of cancer, particularly of bone cancer or leukemia and can produce birth and genetic defects.

The response team, which is used by the DOE to monitor nuclear facilities, was also sent to Canada to detect the location of radioactive debris from the disintegrated Soviet satellite.

Although Denver has been the focal point of radioactive protection surveys over the past week by officials of the Environmental Protection Agency (EPA) and the Colorado Department of Health, locations in Chicago, Baltimore and New York City as well as sites in Pennsylvania and New Jersey have now been added to the list.

Records kept by the Colorado Bureau of Mines between 1910-1930 indicate that in addition to Denver, radium refineries and hospitals engaged in extensive radium therapy were also located in these areas.

The Denver search has been intensified partially because some dump sites have been discovered accidentally. One such site was reportedly discovered by an investigator who was sitting on a bus when his radiation detection equipment went off.

Don Hendricks, director of the office of radiation program of EPA in Las Vegas, Nev., was the man who first discovered the reference to these sites while researching old Bureau of Mines records. He said that EPA officials, working on a list of 50 addresses with staff members of the Colorado Department of Health, have confirmed 15 sites with excessive radiation emission, some locations registering between 500 to 1500 microroentgens an hour. Normal background radiation is typically 20 to 25 microroentgens.

All of the Denver radium dumpsites are now either industrial sives or vacant lots. According to statements made by Jim Montgomery, the Colorado Department of Health section chief for radiological health, "the discoveries haven't brought on a public health crisis. But we have this material spread all over Denver and it is spread completely out of control in terms of us protecting people. It's like a natural disaster, like a tornado or hurricane."

While the health department doesn't feel the sites present and immediate health hazard to anyone, some of the sites will be barricaded and radiation signs will be posted to keep people out.

On industrial sites that have employes working where gamma radiation is shown to be excessive, the EPA has asked that those employes be moved to other areas of the plant.

Nearly 100 Denver residents have been found to work in areas where gamma radiation exceeds acceptable limits. It's risk, similar to that of nuclear workers employed at Hanford, Wash., or Portsmouth, N.H., according to Dr. John Cobb of the University of Colorado Medical Center in Denver.

The Colorado Department of Health is conducting tests upon these individuals. Initial reports indicate that they have not inhaled or ingested the detectable amounts of radiation. Blood tests that might indicate chromosome damage have not yet returned from the labs.

The discovery of the first of these radium sites was made recently when Hendricks, researching the records to get a listing of all the old uranium mill sites in the West as required under a Uranium Mill Tailing Act, found a reference to National Radium Institute in Denver.

Hendricks could not recall ever hearing of such an institute and so he called EPA's regional office in Denver. A check of old telephone books uncovered not only the name and location of the National Radium Institute, but also listed several other radium refineries as well.

A site-by-site search was begun to determine if some of those sites might be emitting hazardous levels of gamma radiation. They were.

In the years between 1910-1930, soon after chemist Marie Curie discovered radium in uranium ores and devised a method of extraction, a radium mania took over in the United States.

For a time, it was claimed that radium could miraculously cure cancer. News accounts of the period reported that an injection of radium solution would cure cancer of the tongue, that it was useful in curing ulcers, and that "the acute trouble in the esophagus of Rev. Dr. W. Meenam yields to treatment." Radium water was sold as a beverage, was used in nose swabs and suppositories and was said to provide a cure for deafness.

The extraction of radium became a lucrative industry and prices for a milligram of radium reportedly reached as high as $125.

Refineries were established in the United States and records indicate that one refinery in Denver made a million dollars annually for four years before 1919.

By the late 1920s, claims for radium as a cure-all faded. Lawsuits began to be filed by the families of women who had worked as radium dial painters. Some of the women had died and some had transmitted genetic defects to their children.

Today, the site of the National Radium Institute is occupied by the Robinson Brick and Tile Co., which took over the buildings in the mid-1940s. Gamma radiation tests at the site have turned up patches reported to range from 1,000 to 3,000 microroentgens an hour.

The cleanup is expected to cost several million dollars and the state is seeking federal assistance to help with the expense.

Such clean-up projects are not new to Colorado. Several years ago the health department had a a radiation detection and cleanup project in Grand Junction. Uranium mine tailings had been used as landfill beneath a number of houses. Over 600 locations were discovered to exceed acceptable levels and the contaminated soils beneath the houses had to be dug up and repiaced.