A yearlong survey shows that 13 percent of Utah homes tested are above the Environmental Protection Agency's warning level for radioactive radon gas.

Also, the background level of radon gas in Utah homes is more than double the national average, according to the Utah Bureau of Radiation Control.The situation is alarming, says Rudy Lukez, conservation chairman for the Sierra Club's Utah Chapter. "The state needs to take a good hard look at those numbers and really assess, do we have a situation where the public health and public safety are being harmed?"

Radon is linked to lung cancer. It is released by naturally radioactive elements in the soil, and is detectable only with radiation monitoring instruments. It's found in some topsoils, black shales and granites.

In regions of high radon concentrations, it tends to seep into and accumulate in poorly ventilated basements. It enters homes mostly through cracks or unsealed holes in foundations or walls.

Homeowners in 24 of Utah's 29 counties volunteered for tests by the preferred type of radon monitoring devices, long-term "alpha track etch" samplers. They were used for 12 months by 608 homeowners.

The results are not encouraging for some 80 of the homes surveyed.

Dane Finerfrock of the Bureau of Radiation Control said Utah's background level of radon was discovered to be 2.6 picocuries per liter. The EPA estimated the national average at 1, and recommends further evaluation of a home only if the radon concentration exceeds 4.

Finerfrock said the highest concentration detected was in a home in South Ogden, at 68 picocuries per liter - 17 times the level at which the EPA suggests an evaluation. The owner of that home was informed of the reading, but has not contacted the state with any request for assistance, Finerfrock said.

In Salt Lake City, a full range of readings was discovered from background concentrations to more than 20.

Asked if there is any danger to those living in homes with the highest range, he said, "There is not an immediate risk, if that's what you mean. It's a long-term problem."

The long-term risk is lung cancer, he said.

In comparison with 15 states that have conducted similar studies, 13 had a larger percentage of homes with concentrations exceeding 4, including Colorado and Wyoming.

The bureau plans to conduct additional surveys in parts of the state that seem to have a greater proportion of homes with elevated concentrations. It will also give technical assistance to those who want to reduce significantly high radon levels identified by the results.

Lukez said, "When you're talking about 13 percent, there's a pretty good probability that your home could be involved with this radon problem." It may be similar to the problems with asbestos a few years ago, before anyone realized the extent of the danger from that once-common insulating material, he said.

Anyone who wonders whether he has a problem should contact a testing company designated as proficient by the EPA, and have a test performed. A list of such testers is available from the Utah Health Department, Post Office Box 16700, Salt Lake City, UT 84116-0700.

For more information, contact the bureau at 538-6734.