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published in the November 2004 Environmental Design + Construction website

Dealing with the Dangers of Radon in our Homes

By Richard A. Cason

Most people know that cigarette smoking is the leading cause of lung cancer in the United States. However, did you know that the second leading cause of lung cancer is radon? Radon is a radioactive odorless, invisible, tasteless gas that causes between 15,000 and 22,000 lung cancer deaths each year. Nearly 1 out of every 15 homes in the U.S. is estimated to have elevated radon levels. According to Raymond Jester, State of Oregon, Department of Health Services, any level of radon is harmful. In fact, over 50 percent of radiation exposure you'll receive in your lifetime is from radon. Since the effects of radon generally are evident only over the long-term, they can be easily ignored.

In 1984, Stanley Watros, a construction engineer at a nuclear power plant in Montgomery County, Pennsylvania, set off the radiation monitor while at work. The problem was that the plant was still under construction and no radioactive materials were present at the site. After further investigation, it was discovered that his house had high radiation levels from radon gas. He picked up enough radon at his home to set off radiation monitors. In fact, the levels were 675 times the maximum levels permitted in a uranium mine. The risk associated with living in Mr. Watros' house was equivalent to smoking 135 packs of cigarettes per day.
Radon comes from the natural breakdown (radioactive decay) of the uranium in rocks and the soil. Radon can move through small spaces in soil and rocks into the air and into your home.

Radon itself breaks down and forms decay products that cling to dust and other particles in the air. As you breathe, these particles can become trapped in your lungs along with the decay products. As these trapped products continue to decay, they release small bursts of energy that can damage lung tissue and lead to lung cancer. As one can imagine, smoking plus radon is a combination that greatly increases the risk of lung cancer.

Radon can seep into a home through floors, cracks in concrete floors and walls, around floor drains and sump pits, joints and cracks, or pores and unfilled cavities in hollow-block basement walls. Your house acts as a vacuum cleaner, sucking up and drawing soil gases into the home through virtually any small crevice, even by diffusion through solid concrete. Radon can also enter your home through well water and be released into the home when the water is used. In rare situations, radon may even be released from the materials used to construct a home.

According to the Oregon Health Services/Radiation Protection Services, indoor radon concentrations are influenced by weather, season, geology, type of construction and heating, ventilation, and air conditioning systems. The Health Services Department recommends testing all residences, specifically the living areas, on a long-term basis to evaluate the annual average concentration. When the annual concentration in a living area of a home exceeds 4 picocuries per liter (pCi/L), it is recommended that measures be taken to remove the radon.

Fortunately, radon testing is easy to perform. You can test your own home or, as we recommend, hire a NEHA-NRPP certified radon professional. Either approach takes only a small amount of the homeowner's time or effort.

If you are concerned that your house may have radon, the National Safety Council offers these tips:

• Do-it-yourself test kits are available for $10 to $25 from most hardware stores and other retail outlets. Choose a reliable test kit.
  
• Look for the words "Meets EPA Requirements" or "EPA Listed" on the package.
  
• Professional testing firms, listed by the state, can test your home for you. You will want to get more than one estimate. Remember to check references when hiring a tester.
  
• Testing periods range from a few days to a year. Long-term tests are more accurate in predicting the year-round levels in your home.
  
• If a test indicates an elevated radon level, always test twice before taking action.
  
• Always consult an NEHA-NRPP-certified radon contractor. They have been trained to evaluate the situation and help you select the right solution.

If radon is found in your home, especially at concentrations of 4.0 pCi/L or greater, consult an NEHA-NRPP certified radon contractor to devise a Radon Reduction System to remove air from beneath the house.

Mitigation for homes with high radon levels is no more costly or involved than many other common household repairs and will not change the appearance of your home.

Richard A. Cason, Alpha Environmental Services, Inc., is certified for radon measurement and certified for radon mitigation through NEHA-NRPP (National Environmental Health Association-National Radon Proficiency Program) with more than 20 years experience in the construction field. Contact Alpha Environmental Services, Inc., Portland, OR, at info@alphaenvironmental.net.