Tests of Homes for Radon Gas Urged by EPA

Preliminary geological surveys indicate that residents in many areas of the country, including Central and Southern California, may be at risk from naturally occurring but potentially harmful radon gas and should consider testing their homes for contamination, Environmental Protection Agency officials said Thursday.

However, a California scientist familiar with the situation said knowledge about the gas is so scarce that home tests would be “premature.” In fact, he predicted that few high radon levels will be found in California.

At a news conference, EPA officials said at least 7 million or 12% of the nation’s households may be contaminated by high levels of the colorless, odorless gas, which is produced by the radioactive decay of uranium in the soil. Scientists estimate that radon may be responsible for up to 20,000 lung cancer deaths each year.

Calling it a “serious public health problem,” EPA Deputy Administrator A. James Barnes said residents in areas that have substantial uranium deposits should contact state health officials to learn how to test their homes. Testing kits can be purchased commercially, officials said.

“Citizens need to understand the hazards they face and they need to know what steps they can take to reduce radon risks in their homes,” he said.

The agency’s survey identified high concentrations of uranium around the country. In California, areas of an EPA map shaded to indicate a potential problem include the San Joaquin Valley and scattered spots in Southern California.

A uranium deposit alone does not produce a hazard. Other factors include the permeability of the soil, which allows the gas to seep upward, and the construction and ventilation of the home. On the East Coast, where some radon measurements have been taken, houses with acceptable levels of the gas have been found next-door to homes with extremely high concentrations.

Radon seeps into homes through cracks and gaps around pipes, EPA officials said. Dangerous concentrations were first discovered in Pennsylvania 18 months ago after a nuclear power plant worker repeatedly set off radiation alarms when he reported to work. The problem was finally traced to radon in his home that measured at 675 times the normal level.

Federal officials have tried since then to develop a nationwide program to study radon, set tolerance standards and teach private contractors how to test and seal homes.

At its news conference, EPA announced that it has set four picocuries per liter of air as the level above which homeowners are advised to take action to reduce radon. A picocurie is a unit used to measure radiation. Officials said that standard was chosen because technology is not available yet to reduce contamination below that level. Living in a home with that level for a lifetime would be the equivalent of smoking half a pack of cigarettes a day, they said.

Exaggeration Seen

But Anthony Nero, a scientist at Berkeley Lawrence Laboratory, said he believes that the EPA’s risk estimates are exaggerated. Nero estimated the risk of four picocuries per liter as equivalent to smoking “a tenth of a pack of cigarettes” a day.

“The fact is that the risk that one ordinarily accepts by living in a house or driving a car is in that same range,” he said.

Nero said that California, like most states, has not yet completed any radon testing and that it would be “premature” to advise residents to screen their homes based on a map indicating uranium deposits.

The agency expects to complete a national study of indoor radon contamination within a couple of years. The survey will include random sampling of 10,000 homes throughout the nation.

$10,000 Study Under Way

Eight months ago, a $10,000 radon study was launched in the Los Angeles Basin by the privately funded Foundation for Advancement in Science and Education and the County of Los Angeles.

Radon monitors were placed in 100 homes throughout the basin. Results of the tests are expected in six to nine months.

‘More information is needed, and there seems to be a very definite lack of information as to the radon levels in Los Angeles homes,” said Steven Heard, president of the foundation.

He said radon monitors, known as Track Etch monitors, have been placed in homes in the San Fernando Valley, Franklin Canyon, Silver Lake, Santa Monica, Venice and Long Beach.

Times staff writer Larry Stammer contributed to this story from Los Angeles.