Radon is a naturally occurring radioactive gas that causes lung cancer.
What is an Acceptable Level?
EPA states that any radon exposure carries some risk; no level of radon exposure is always safe. However, EPA recommends homes be fixed if an occupant's long-term exposure will average 4 picocuries per liter (pCi/L) or higher.
What is a "picocurie" (pCi)?
A pCi is a measure of the rate of radioactive decay of radon. One pCi is one trillionth of a Curie, 0.037 disintegrations per second, or 2.22 disintegrations per minute. Therefore, at 4 pCi/L (picocuries per liter, EPA's recommended action level), there will be approximately 12,672 radioactive disintegrations in one liter of air during a 24-hour period.
What is a "working level" (WL)?
Some devices measure radiation from radon decay products, rather than radiation coming directly from radon. Measurements from these devices are often expressed as WL. As noted above, conversions from WL to pCi/L are usually approximate. A level of 0.02 WL is usually equal to about 4 pCi/L in a typical home.
If a working level (WL) value is converted to a radon level (pCi/L), the conversion is usually approximate and is based on a 50 percent equilibrium ratio. If the actual equilibrium ratio is determined (which is rare), it should be stated. The 50 percent ratio is typical of the home environment, but any indoor environment may have a different and varying relationship between radon and its decay products.
Technically speaking, 1 WL represents any combination of short-lived radon decay products in one liter of air that will result in the ultimate emission of 1.3 x 105 MeV of potential alpha energy.
How often is indoor radon a problem?
Nearly one out of every 15 homes has a radon level EPA considers to be elevated - 4 pCi/L or greater. The U.S. average radon-in-air level in single family homes is 1.3 pCi/L. Because most people spend as much as 90 percent of their time indoors, indoor exposure to radon is an important concern.
How does radon get into a building?
Most indoor radon comes into the building from the soil or rock beneath it. Radon and other gases rise through the soil and get trapped under the building. The trapped gases build up pressure. Air pressure inside homes is usually lower than the pressure in the soil. Therefore, the higher pressure under the building forces gases though floors and walls and into the building. Most of the gas moves through cracks and other openings. Once inside, the radon can become trapped and concentrated.
Openings which commonly allow easy flow of the gases in include the following:
• Cracks in floors and walls • Gaps in suspended floors
• Openings around sump pumps and drains • Cavities in walls
• Joints in construction materials
• Gaps around utility penetrations (pipes and wires
• Crawl spaces that open directly into the building
Radon may also be dissolved in water, particularly well water. After coming from a faucet, about one ten thousandth of the radon in water is typically released into the air. The more radon there is in the water, the more if can contrilbute to the indoor radon level.
Trace amounts of uranium are sometimes incorporated into materials used in construction. These include, but are not limited to concrete, brick, granite, and drywall. Though these materials have the potential to produce radon, they are rarely the main cause of an elevated radon level in a building.
Outdoor air that is drawn into a building can also contribute to the indoor radon level. The average outdoor air level is about 0.4 pCi/L, but it can be higher in some areas.
While radon problems may be more common in some geographic areas, any home may have an elevated radon level. New and old homes, well-sealed and drafty homes, and homes with or without basements can have a problem. Homes below the third floor of a multi-family building are particularly at risk.
House sales today are becoming more complex and in today's tough market, lenders are requiring more information from borrowers and more information about the property.
Home buyers and sellers are much more aware of radon today and with continuing campaigns to raise pubic awareness from organizations such as the EPA, Iowa Department of Health and the American Lung Cancer, that awareness will only continue to rise. These and other organizations have been responsible for having January declared National Radon Month and for new building codes requiring new homes to be built with radon reduction systems.
Having a home tested for radon before the sale is becoming the standard now and it can protect both you and you clients. In fact, a home that has been tested and found to have low levels of radon or that has been mitigated can be a strong selling point. As the realtor, you should be knowledgeable about radon testing and mitigation since your client will probably look to you for information.
If you are representing the buyers, make sure the home is safe and have it tested. If the levels are high you can negotiate with the sellers so your client doesn't absorb all of the costs associated with mitigation.
If you are representing the sellers, have a test done early so if the levels are high, your client can take care of it in a timely manner, before it scares away a potential buyer.
Nobody wants high radon levels to cause a buyer to back out of a sale, so why not have a test done a soon as possible. If the levels come back low you can use that as a selling point and know it will not be a problem at closing. If the levels do come back high, you have time to decide what to do and to take action.