WHERE DOES RADON COME FROM?

Radon comes from the natural radioactive decay of radium and uranium found in the soil beneath the house. The amount of radon in the soil depends on complex soil chemistry, that varies from one house to the next. Radon levels in the soil range from a few hundred to several thousands of pCi/L. The amount of radon that escapes from the soil to enter the house depends on the weather, soil porosity, soil moisture, and the suction within the house.

HOW DOES RADON GET INTO THE HOUSE?

Houses act like large chimneys. As the air in the house warms, it rises to leak out the attic openings and around the upper floor windows. This creates a small suction at the lowest level of the house, pulling the radon out of the soil and into the house. You can test this on a cold day by opening a top floor window an inch. You will notice warm air from the house rushing out that opening; yet, if you open a basement window an inch, you will feel the cold outside air rushing in. This suction is what pulls the radon out of the soil and into the house. You might think caulking the cracks and the openings in the basement floor will stop the radon from entering the house. However, scientific studies show, it only takes enough unsealed cracks or pin holes in the caulking to equal a hole 1/2" in diameter to let all the radon in. It is unlikely that caulking the accessible cracks and joints will permanently seal the openings radon needs to enter the house. The radon levels will still likely remain unchanged.

Fortunately, there are other extremely effective means of keeping radon out of your home. Throughout the country, several million people have already tested for radon. Some houses tested as high as 2,000-3,000 pCi/L; yet, there hasn't been one house that could not mitigate to an acceptable level. Mitigation usually costs between $500-$1500.

WHAT ABOUT RADON IN WELL WATER?

Underground well water can transport the radon from the soil into the house, when taking a shower, doing laundry, or washing dishes. The EPA says it takes about 10,000 pCi/L of radon in water to contribute 1.0 pCi/L of radon in air throughout the house. The ratio of radon in water to radon in bathroom air while showering can be much higher, typically from 100 to 1; to about 300 to 1. The average Colorado well tests about 3,000 pCi/L with one well testing more than 3,000,000 pCi/L.

WHAT ABOUT RADON IN CITY WATER?

If your water comes from a municipal reservoir supply, you need not worry about radon in the water. When radon in water is stored in a reservoir for more than 30 days, the radon decays away to practically nothing. Every 3.825 days half the radon disappears through natural radioactive decay.

WHAT IS THE RISK OF RADON EXPOSURE?

Scientists believe radon exposure is the second leading cause of lung cancer. When radon decays, it shoots off alpha particles. These are small, heavy, electrically charged, sub-atomic particles consisting of two protons and two neutrons. If an alpha particle strikes the chromosomes in a lung cell, it could alter the way that cell reproduces. Our bodies immune system should recognize and destroy these mutant cells before they can multiply over the next 10 to 20 years into a recognizable cancerous growth.

Some peoples immune system is better than others. Because of these inherent differences, radon doesn't affect everyone the same.

HOW SERIOUS A RISK IS RADON?

According to the following EPA radon risk chart, radon is a serious health problem.

HOW CAN I LEARN MORE ABOUT RADON?

The EPA's hotline at 1 800-SOS-RADON will be happy to answer your questions and send you their pamphlets about radon. They can send you a list of radon contractors and tell you how to get their technical publications about radon and radon mitigation.

You can call the local Department of Health.
EPA's Position on Radon
EPA'S Radon Publications

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