“RADON GAS: Radon is a naturally occurring radioactive gas that, when it has accumulated in a building in sufficient quantities, may present health risks to persons who are exposed to it over time. Levels of radon that exceed federal and state guidelines have been found in buildings in Florida. Additional information regarding radon and radon testing may be obtained from your county health department.” (Fla. Stat. § 404.056)
While the above disclosure is required by Florida law to be in all contracts for the sale, purchase or lease of residential real estate, this is what the Florida Department of Health says about radon in buildings, “Radon, a Class A carcinogen, is the second cause of lung cancer. Radon is responsible for more than 21,000 lung cancer deaths a year (one every 25 minutes.) In Florida, one in five homes tested has elevated radon levels above the EPA action level of 4 pCi/L.” (FL Dept of Health) “In some areas of Florida, one out of two homes has excessive amounts of radon”. (FL Dept of Health).
While we hope the above gets your attention, finding elevated radon levels is something that can be easily mitigated, and relatively inexpensively at that. The most important thing though is not exposing yourself or your family to this unnecessary health risk.
What is radon?
Radon is formed by the natural radioactive decay of uranium in rock, soil and water. Low levels of uranium occur widely in the Earth’s crust and can be found in all 50 states. This highly carcinogenic gas is colorless, odorless and tasteless. Unless you test for it, there is no way of telling how much is present in your home. The US Environmental Protection Agency and the Surgeon Generals Office have estimated as many as 20,000 lung cancer deaths are caused each year by radon. This is second only to smoking.
Why should I be concerned?
As the radon gas enters your home it is undergoing radioactive decay, emitting ionizing radiation in the form of alpha particles and short-lived decay products called progeny, some of which are also radioactive. As the decay of these progeny continues, radiation is continually released. Unlike radon, the progeny are not gases, and they can easily attach to dust, pollen and other particles. These particles can then be transported by air and can also be breathed. When you breathe in air containing radon, you are at an elevated risk for lung cancer.
Why should you test for radon?
Testing is the only way to know your home’s radon levels. There are no immediate symptoms that will alert you to the presence of radon and it typically takes years of exposure before any problems surface. Current state surveys show that on average, one in five homes tested have a problem. The US EPA, Surgeon General, American Lung Association, American Medical Association and the National Safety Council recommend testing your home.
How do I test for radon?
At Inspect Tally, your Tallahassee Home Inspector, we use continuous radon monitors (CRM) as our radon testing device of choice. These CRMs utilize a pulse ionized chamber to test your home’s levels. This data is uploaded and reviewed by the staff of a national radon company, Radalink, out of Atlanta. We merely place and pick up the monitor following the best practices outlined by the EPA. This device measures and produces results in picocuries per liter of air or pCi/L. The ions are created from the alpha radiation and these ions then are detected by the electrometer. These detectors are typically deployed for a minimum of 48 hours. The monitors are active devices that continuously measure and record the amount of radon and its decay products in the air. These devices are also specifically designed to deter and detect test interference by a third party, which ensures you a more reliable result.
What is the “acceptable” level of radon in the air?
The EPA states any radon exposure carries some risk; no level of exposure is safe. However, they recommend homes be mitigated if an occupants long-term exposure will average 4 pCi/L or higher. The average indoor radon level is estimated to be about 1.3 pCi/L and about 0.4 pCi/L of radon is normally found in the outside air. The US Congress has set a long-term goal that indoor radon levels be no more than outdoor levels. While this goal is not yet technologically achievable in all cases, most homes today can be reduced to 2 pCi/L or below.
What are PicoCuries?
The concentration of radon gas is not measured directly but rather by the radioactivity it produces. It is expressed in picoCuries per liter of air, or “pCi/L”. A Curie is a unit of radioactivity equivalent to 1 gram of radium and the prefix “pico” means a trillionth. In the metric system, radon concentrations is expressed in Becquerels per cubic meter (Bq/m3). One Becquerel means one radioactive disintegration per second, and 4 pCi/L equals to 148 Bq/m3. In an average basement, 38 million atoms will undergo radioactive decay each hour.
The 4 piC/L has become a benchmark for real estate transactions, but that level still carries considerable risk – equivalent to getting a chest x-ray or smoking 10 cigarettes a day.
How does Radon enter a home?
Radon is an invisible and odorless radioactive gas. Elevated levels of radon have been found in homes all across the county. Any home in any state may have a radon problem: new and old homes, well sealed and drafty homes, homes with or without basements. Radon from soil is by far the main source of indoor radon. Radon moves naturally into the permeable disturbed soil and gravel beds surrounding foundations and then inside the building through openings, cracks and pores in concrete. The air pressure inside homes is slightly lower than in the ground, which draws in radon gas from several feet away. The warm air inside buildings moves naturally upwards and this “stack effect” reduces air pressure in basements and crawlspaces. Radon is also pulled through diffusion, which is driven by the difference of radon concentration indoors and in the soil. Diffusion contributes up to 80% of radon levels found in homes.