Invisible enemy
Radon can invade homes, contribute to lung cancer

By Jim Lawly
DAILY Staff Writer
Printed: April 23, 2001; The Decatur Daily News, online edition

You can't see it or smell it, but there might be danger in the air at your house.

Radon, a byproduct of decaying uranium that naturally occurs in soil and rock, is real.

"It's not something the government has made up as just another harmful substance to worry about," said Sabrina Lyle, a North Alabama radon specialist for the Alabama Cooperative Extension System.

It is estimated that lung cancer by radon exposure kills between 15,000 and 22,000 people nationally a year, according to the American Lung Association and National Academy of Sciences.

People know little about it because its effects have become well-known only in the past decade or so, experts say.

Radon enters buildings through cracks in walls, basement floors, foundations and other openings. Although North Alabama is considered a hot spot for radon, you can't be sure whether your home has a radon problem unless you test it. Levels vary so much that your home could have safe radon levels while your neighbor's home could have a high level, experts say.

"It's unpredictable, and tracking if you're likely to have it or not is perplexing," said Jim McNees, director of radioactive materials compliance with the Alabama Department of Public Health. "It has a lot to do with cracks or fissures in the layers of soil underneath you."

One way to get a picture of radon is to imagine microscopic objects floating in the air that emit high-energy particles. Over a lifetime, these particles can enter lungs and attach themselves, and may eventually lead to lung cancer, Ms. Lyle said.

Radon seeps upward similar to a gas. Whether your home has a concrete flooring or has an open crawl space with no layering, the idea behind protecting yourself from radon is to form a barrier, then divert radon outward. The Environmental Protection Agency says there are different ways to lower radon levels, from sealing cracks in floors and walls to changing the flow of air into the building.

One popular method is called sub-slab depressurization. This uses pipes and fans to remove radon gas from beneath the concrete floor and foundation before it enters your home. The radon is vented above the roof via PVC piping, similar to the ways vent piping leads noxious sewer or gas water heater gases outside, Ms. Lyle said.

Another method, often used for homes with no concrete slab, is layering the ground with plastic sheeting. Caulking in openings where blocks or bricks meet flooring, or between spaces in wood flooring, is another way.

"There are different ways to do it, but it depends on how your home is built and how much radon you have," she said.

The Extension System has information on protecting and ridding your home of radon for do-it-yourselfers, and can provide contacts for contractors who specialize in radon mitigation. Hiring a contractor to lower radon levels costs between $800 and $2,500.

"It's not as complicated as it sounds," Ms. Lyle said.

Finding out about radon levels in your home also is simple. One-time and long-term testing kits are available at many home stores and department stores for about $25 to $30 each. You also can buy test devices from the Extension System offices for $5 for short-term devices and $15 for long-term devices.

The devices are placed in the occupied room at the lowest level of the home -- if you use the basement as an occupied space, you place it there. After leaving the device there for two to 90 days (depending on the type of kit) you mail it to a laboratory. Results take about two to three weeks.

"A level of four picocuries per liter (pCi/L) of air is considered harmful, according to the EPA," Ms. Lyle said. "Any exposure to radon is bad for you."

McNees said studies show that two of 1,000 nonsmokers and 27 of 1,000 smokers with long-term radon exposure of four picocuries per liter developed lung cancer.

That amount of exposure is like smoking a pack of cigarettes a day, Ms. Lyle said.
(Correction: Actually, living in a home with a 4.0 pCi/l level of radon in an 18-hour day is equal to smoking 8 cigarettes a day.)

In a state survey for radon exposure in homes conducted between 1987-97, 12.3 percent of homes in Limestone Country, 10.1 percent of Lawrence County and 29.4 percent of Morgan County homes were found to have unacceptable levels of radon, McNees said.

"If you live in North Alabama, we highly recommend that you get your home tested for radon exposure," he said.