Utah residents may be exposed daily to a colorless, odorless gas without their knowledge, and the Utah Department of Environmental Quality would like to increase awareness throughout the state.

"It certainly should send the message that you could be living in a home that has radon," said Donna Kemp Spangler, spokeswoman for the DEQ.

Spangler said numerous public information sessions are being held throughout the month to educate residents about the danger that may be in their homes.

It is also important to train real estate agents in the dangers of the gas, she said, so they can assist buyers and sellers of homes in fixing the problem.

"They're dealing in the buying and selling of homes," she said. "Because radon does cause lung cancer after prolonged exposure, it's important for real estate professionals to be educated."

The department has been trying to the educate the public for some time, and Spangler said she hopes the danger of radon is becoming more widely known.

Radon gasses come from uranium-bearing granite deposits in the soil, according to the DEQ Web site. Although uranium is used in nuclear materials, Spangler said the radon gases in homes is not a man-made problem.

"A lot of it is natural," she said. "It's found in the geology of the Rocky Mountains."

High levels of radon can cause lung cancer, but the health effects of the gas cannot be seen until the cancer develops, said John Hultquist, DEQ section manager. There is no way to know if your home is affected unless tests are run.

Radon can creep into the home from the ground, so Holtquist said the best place to test for the gas is in the lowest level of the home. The best time to test is in the winter, when the warmer air in the house has lower pressure than the cold ground and draws in the most radon.

The highest levels of radon will be in the home in the winter, he said, so if the result is lower than EPA standards it will also be lower in the summer, though the opposite is not always true.

"It's the worst time, or worst case possibility, for radon to be in the home," he said.

Hultquist said winter is the ideal time for testing because the three to seven day tests require doors and windows to be shut almost all the time. During cooler weather, people are less likely to leave windows open. The use of swamp coolers in the summer can also bias the test, he said.

The national average for radon levels is 1.5 picoCuries per liter of air, while the Utah average is 4.6, Hultquist said. The EPA standard level at which action should be taken is 4 picoCuries.

Although levels vary from home to home, areas in Utah, Wasatch, Juab and Salt Lake counties have levels between four and 10 picoCuries, according to the DEQ.

Hultquist said it is important to test homes for the gas and take measures to reduce the level, even if no effects have yet been seen.

"The higher the concentration, the longer the exposure, the greater the risk," he said.

It is possible to reduce the levels of radon in a home using a certified provider found on the DEQ Web site. Depending on the method used, Hultquist said the cost averages between $1,200 and $1,600.

Utah County Health Department spokesman Lance Madigan said testing kits are available through the department for $10. The all-inclusive kits are easy to use if homeowners follow the directions, he said. The kits are also available at Home Depot or Lowe's, but Madigan said the health department keeps them on hand because residents expect the service.

A public information session on radon and how to improve air quality in the home will be from 6-7 p.m. on Jan. 9 at the Provo City Library, 550 N. University Ave. For more information, visit www.radon.utah.gov.