Test Homes for Radon, EPA Says : 7-State Survey Finds Radioactive Gas More Prevalent Than Believed

Times Staff Writer

The Environmental Protection Agency and the surgeon general’s office issued an unprecedented advisory Monday urging virtually every homeowner in the country to test their houses for the presence of radioactive radon gas.

They said that based on the latest federal survey of 11,000 homes in seven states and a 10-state survey last year, radon is far more widespread than previously thought and present in dangerous concentrations in a significant percentage of homes.

One in three homes tested in the seven states exceeded the EPA recommended maximum concentrations of 4 picocuries per liter of air, and between 1% and 2% exceeded 20 picocuries per liter, the level at which the EPA advises that immediate actions be taken to lower the levels.

Active Radon Region


They also disclosed for the first time the discovery of an active radon region stretching throughout Minnesota and North Dakota where concentrations of the gas were as severe as those found in the Reading Prong, the geological formation that runs through New Jersey, New York and Pennsylvania. Tests of homes in the Reading Prong several years ago alerted scientists to the possibility of a widespread radon hazard.

“We have a problem that is national in scope . . . and the problem is one that in some states is fairly widespread,” EPA Administrator Lee M. Thomas told a crowded press conference.

“The surveys bring us to the conclusion that we think it’s important for everyone to test their home,” Thomas said.

He strongly recommended testing of homes, townhouses or row houses, as well as basement living areas and first- or second-floor apartments.


At the same time, Vernon J. Houk, the assistant surgeon general--speaking for Surgeon General C. Everett Koop--urged physicians and other health professionals throughout the country to immediately familiarize themselves with the radon issue and lead efforts to educate the public about its dangers. He said it is especially important for them to warn of the deadly combination of smoking and radon that can multiply an individual’s risk of lung cancer by as much as 15 times or more.

Based on studies of lung cancer among uranium miners known to have been exposed to radon, the EPA has estimated that between 5,000 and 20,000 people die each year of lung cancer due to radon exposures in their homes. The National Academy of Sciences has placed the death rate due to radon-induced lung cancer at 13,000 a year. By contrast, the National Cancer Institute estimates that all lung cancer deaths this year will total 139,000, the vast majority caused by smoking tobacco.

California Not Surveyed

California was not among the 17 states surveyed by the EPA, but there are preliminary indications that radon may not be as widespread a problem in Southern California overall. A study co-sponsored by Los Angeles County Health Services Department and the Foundation for the Advancement of Science and Education found a year ago that of 100 homes tested, none were found to exceed the EPA action level of 4 picocuries.


Nonetheless, individual homeowners in Los Angeles County have reported isolated readings higher than 4 picocuries, and the California Department of Health Services suspects elevated levels in parts of the San Joaquin Valley and the Santa Cruz area. Even in areas where radon levels are not generally high, it is possible that there could be dangerous levels in a particular house. The only way of knowing is to test. The state is embarking upon a $200,000 radon study, but results are not expected for at least a year.

In Sacramento, the state Department of Health Services issued a statement saying it could not endorse the EPA’s position. “The state is not prepared to suggest that every homeowner have his home tested for radon. . . . The state does encourage homeowners to learn as much as they can about radon, and we hope to assist with the publication of a booklet which is scheduled to come out in the next six months,” said Ken August, a department spokesman.

The EPA advisory Monday was a dramatic departure from its previous policy of suggesting such tests only when homeowners believe they have a problem or live in an area known to be a radon “hot spot.” But it was not greeted with universal applause.

Anthony V. Nero Jr., a scientist at the University of California’s Lawrence Berkeley Laboratory who has long studied radon, said Monday there was no justification for radon testing by everyone.


Nero said the homes surveyed by the EPA were measured only for a 48-hour period. But, he said, radon levels can ebb and flow from day to day and month to month. For that reason, Nero said he is convinced that had the measuresments been conducted over a 12-month period that many of the houses the EPA reported Monday as exceeding the 4-picocurie action level would not be that high over a year’s time.

“I think their previous policy was more sensible,” Nero said.

Kai-Shen Liu, an epidemiologist with the California Department of Health Services, questioned the methodology used by the EPA. “I’m still not convinced by the EPA’s data. They extrapolate from 48 hours to a year. I just cannot buy that. And to use that result to say every house should be monitored, I just can’t agree with that. It’s like AIDS. You shouldn’t screen everybody. But for the high-risk groups you should do that.”

California Not in Study


Liu said California did not participate in the EPA study because it would have had to go along with the EPA’s testing protocol. States are asked by the EPA to volunteer to participate in the screenings on the condition that they follow the EPA’s procedures so that the data from each state is comparable.

Despite reservations from several scientists, Thomas and Houk said they felt more than justified in the recommending nationwide testing.

“If we can’t believe these data, we can’t believe data on anything,” Houk said.

Thomas reported that 60% of houses tested in North Dakota and more than 45% of those surveyed in Minnesota had radon levels that exceeded the EPA’s maximum recommended level of 4 picocuries per liter of air. Previous studies by others, including UC’s Lawrence Berkeley Lab, found high radon levels in the Red River Valley region in those two states.


At 4 picocuries per liter, the risk of lung cancer from radon is comparable to an exposure of 200 to 300 medical X-rays each year, or smoking a half a pack of cigarettes daily. A picocurie is a standard unit of radiation measurement. Houk, mindful of controversy over what is a safe level, said 4 picocuries per liter is not a safe level, but probably the lowest achievable level in most homes because of the limitations of technology and financial constraints.

Nationally, they said between 8 million and 12 million homes may exceed the action level of 4 picocuries per liter.

Houk said, “In this country we test our homes . . . for termites. We do this to this to protect the financial institutions lending the money from loss. I would suggest it is now time to certify our homes free from radon as we live in them and when we move into a new house. We’re not protecting financial institutions. We’re protecting our health and the health of our children.

“I would not buy a house, I would not move into a house unless I knew what the individual radon levels were of that house . . . particularly if you have a child.” He noted that risks are based on a 70-year lifetime and children would be at greater risk than adults.


There is widespread agreement that radon is the single largest source of human exposures to ionizing radiation in the environment. For most of the nation’s population, radon exposures far exceed the combined radiation from all other natural and man-made sources, including cosmic rays from space, medical X-rays, nuclear power plants and the fallout from atmospheric nuclear weapons explosions.

Decay Product of Radium

Radon is a decay product of radium, which in turn is produced by the breakdown or atomic decay of uranium. As the gas decays, alpha particles known as radon daughters are emitted. It is the radon daughters, which are atoms of heavy metals, that pose the actual health threat. They attach themselves to dust or smoke particles that are inhaled and lodge in the lungs where they continue to radiate. The radiation can induce lung cancer over a period of time. The risk depends on the level of radon concentration and the amount of time a person is exposed.

Radon, first discovered in the early 1900s, occurs naturally in the soil everywhere. Because of slight differences in air pressure inside the house and outdoors, the radon can be drawn into the house, much like smoke is drawn up a fireplace chimney. The gas enters through cracks in concrete slab foundations and other openings, such as might be found around plumbing.


Thomas said initial screening tests can cost from $10 to $25. Tests kids are available from numerous companies. If the screening shows levels exceeding 4 picocuries per liter of air, Thomas said a follow-up test to confirm the result should be made before undertaking steps to reduce the infiltration of radon into the house. Costs to reduce radon levels can run from several hundred to several thousand dollars. The higher the radon levels, the sooner action should be taken, he said.

“The good news is that, like smoking, the radon risk is reduced when the source is removed,” Houk said.

The EPA has certified more than 1,000 companies for radon testing. The names of testing firms are available by writing EPA’s regional headquarters Library Information Center, 215 Fremont St., San Francisco, 94105. The phone number is (415) 974-8076.

The seven states surveyed this year were Arizona, Indiana, Massachusetts, Minnesota, Missouri, North Dakota and Pennsylvania, and Indian lands in Michigan, Minnesota and Wisconsin. The 10 states surveyed last year were Alabama, Colorado, Connecticut, Kansas, Kentucky, Michigan, Rhode Island, Tennessee, Wisconsin and Wyoming.


Seven states to be surveyed this winter are Alaska, Iowa, Maine, New Mexico, Ohio, Vermont and West Virginia and Indian lands in New Mexico, Colorado, North Dakota, South Dakota and Iowa.