The colder months always bring on stories about accidental deaths from carbon monoxide poisoning in the home. The U.S. Consumer Product Safety Commission (CSPC) estimates that about 200 people die each year from carbon monoxide poisoning associated with home fuel-burning heating equipment.

But there is an even more dangerous, though little-noticed, killer lurking in many homes -- and just like carbon monoxide, it is invisible, odorless and tasteless.

It's radon -- a radioactive gas that comes from the breakdown of uranium in soil.

According to the U.S. Environmental Protection Agency (EPA), radon is the second-leading cause of lung cancer in the U.S. and is associated with up to 22,000 lung cancer deaths per year.

Radon is commonly found in the air and water, where it poses little risk. But but radon that creeps into your home from the soil can be a much greater risk.

Radon can enter homes through cracks in the foundation or flooring, so higher levels of radon are normally found in the basement and first floor. It doesn't matter if your home is old or new, high levels of radon have been observed in every type of dwelling, in every part of the country.

Not just hype

While there are critics who claim the radon problem is nothing but hype, every major health organization has found that long-term radon exposure causes cancer.

These include the Environmental Protection Agency, the Centers for Disease Control and Prevention, the American Lung Association, the American Medical Association, and the National Academy of Sciences.

Researchers first noticed a high incidence of lung cancer in uranium miners, and subsequent studies on rodents confirmed the results.

Critics will point out that miners were exposed to a higher level of radon than most people would have in their home, but health organizations believe that while the level of radon is important, the length of exposure is more significant.

A miner might be exposed to a high level of radon for 8 hours per day. A homemaker might be exposed to a decreased level, but for 18 hours per day or more. Researchers estimate that the same negative effects are likely due to the increased exposure time in the home.

Additionally, because the home is sealed, the colder months can produce higher radon levels. The same applies to a home closed in the summer because of air conditioning.

Home inspectors

Because more consumers have become aware of potential problems from radon, many home inspectors are performing radon testing as part of their routine. This means that radon has had an effect on both home sellers and buyers.

Joseph, of Morristown, New Jersey was one such buyer.

"Everything was done, all the underwriting was complete and then ... the house inspection! With 99% of the loan process complete, the home inspection showed a radon level above the state standard," Joseph told

"This concerned us because of our newborn, so we decided to hold off on the particular house and keep the home search going," Joseph wrote.

Not just homes

It's not just homes that can harbor radon. In Nevada, parents in the Lake Tahoe area are protesting a plan to consolidate two schools, using Zephyr Cove Elementary, which has high radon levels.

According to the Nov. 3 tests done by Fallon Heating and Air Conditioning, five rooms in Zephyr Cove were above the Environmental Protection Agency's recommended action level of 4 picocuries per liter of air.

Blown to bits

In a November, 2007 episode of the ABC show "Extreme Makeover: Home Edition," a large home was blown into toothpicks. The home wasn't blown to bits because it was the scene of a past mass murder. And it wasn't destroyed because it was condemned.

ABC blew up the house because it showed high levels of radon.

"Blowing up your home is not the answer to a radon problem, unless you're looking for good TV ratings," said Gary Hodgden, president of Midwest Radon, based in Olathe, Kansas.

"If a home does test at a high level of radon, there are proven methods that reduce the measurements to a safer level," Hodgden said. "But the first step is to test. Testing is the only way to know if there is a problem."

Hodgden says there are a few different testing methods. The first and quickest is the short-term test, generally a charcoal-based test that takes only a few days.

These kits can be purchased for around $15.00 to $20.00, but be sure to note whether this includes the lab reading and a prepaid return mailer.

On the flipside, a long-term test will give you more accurate results of the year-round radon levels. Typically called an alpha-track test, it will take at least 90 days, but 6 months to a year is recommended. Expect to pay $20.00 to $40.00 for this kit.

"If a neighbor's home has a low level of radon, it doesn't mean you shouldn't test your own residence," Hodgden said. "Everything we know about radon shows that one home can show a low level, but the home next door can test high."

Radon is measured in "picoCuries per liter of air," or pCi/L. The EPA recommends a level at or below 4 pCi/L. Achieving a zero rating is impossible because even the outside air typically has a level of 0.4 pCi/L.

The EPA says that although no amount of radon is safe, most homes can be reduced to a level of 2 pCi/L or below. Additionally, while various removal methods exist, one reduction method has proven to reduce radon levels by up to 99%.

Known as the soil suction system, a small fan draws air from under the home and sends the radon gas through a pipe to the outside.

The cost?

"Consumers can expect to pay anywhere from $800 to about $3,000," Hodgden said. "The cost depends on many factors, such as the type of home, area of the country, etc. Most fans have a five-year warranty, so the only real maintenance is making sure the fan is running."

As Hodgden said, the only way to know if a problem exists is to test. You can find do-it-yourself test kits online or at local hardware and home supply stores. You can also locate a radon specialist in your state by contacting your state radon office.

Many states have safety organizations that sell kits at discounted prices. The Utah Safety Council sells an EPA-approved, short-term test kit for $10.