Radon is an invisible, cancer-causing radioactive gas created during the natural breakdown of uranium in rocks and soils. It becomes a health issue when it seeps into homes through foundations and enters living areas, where it is easily inhaled and brought into contact with lung tissue. Smokers are at a higher risk since radon decay products attach themselves to smoke particles and become trapped in the lungs; non-smokers much more readily exhale the radon particles.

Topics addressed on this page:

Health Threat
Risks and Realities of Radon
Risks for Smokers & Nonsmokers

Health Threat

• Radon is responsible for about 18,000 deaths from lung cancer each year in the U.S. according to 1998 research by a National Research Council committee.
• Many of these deaths could possibly be prevented by reducing home radon concentrations below the "action level" recommended by EPA, said the report. About 6 percent of the homes in the U.S. have higher than EPA recommended radon levels.  The report stated that about 90% of radon-related cancers were reported in current or former smokers and "most of the radon-related deaths among smokers would not have occurred if the victims had not smoked." Smokers are at high risk levels because the effects of the radon are presumed to reinforce those of tobacco smoke producing a combined threat that is greater than smoke or radon alone.
• The report also found that about 2,500 non-smokers die from radon-related cancer each year. The NRC committee believes about 1,000 of these deaths could be prevented by radon abatement.
• The panel stated that there is a "substantial degree of uncertainty" in its estimates, especially those for risk at the very low levels of the gas found in the average home.
• The NRC committee consensus was that there is no "safe" level of exposure because even one radon atom can emit sufficient radiation to cause "extensive damage" to a lung-tissue cell, said panel member Eric Hall of Columbia University.
• About 6 million of the nation's homes have indoor radon levels above the EPA's recommended "action level" of 4 picocuries per liter, according to federal and NRC estimates.

top of page

The Risks and Realities of Radon

Radon is the second highest cause of lung cancer in the United States, with EPA estimating that up to 15,000 Americans die every year from long-term exposure.

Approximately 35 percent of the homes in Montgomery County exceed the EPA suggested action level of four picocuries per liter (4pCi/L), based on almost 34,000 tests conducted through April 1995. And due to geological formations, some areas routinely test higher for radon, particularly Germantown, Boyds, Clarksburg, Colesville, Sandy Spring, and Rockville -- although radon has been detected throughout the county. Moreover, just because a neighbor has a low reading, it does not mean that your exposure is the same. Cracks or flaws in foundations, improperly vented sump pumps, tighter insulation, etc., can cause results to vary widely throughout a community.

Anyone who lives in a single family home, townhome, or ground level apartment or condominium is potentially at risk, although smokers are especially at risk, and can be up to 25 times more likely to contract lung cancer through prolonged exposure.

But there are scientific realities which should be considered to temper the alarming nature of these statistics. As Michele Courville, the Department of Environmental Protection's Indoor Air Quality specialist, points out, there is time for everyone to learn more about radon and the actual health risks from different levels of exposure and periods of exposure. There are a variety of tests for radon, there is help available to interpret test results, and there are certified contractors available to mitigate radon levels through structural improvements, if required at all. Courville stresses that "radon awareness should focus on education, not on anxiety." Radon is a potential environmental health problem, but there are plenty of county resources available to help.

top of page

top of page

Understanding Radon

Radon is an invisible, cancer-causing radioactive gas created during the natural breakdown of uranium in rocks and soils. It becomes a health issue when it seeps into homes through foundations and enters our living areas, where it is easily inhaled and brought into contact with lung tissue. Smokers are at a higher risk since radon decay products attach themselves to smoke particles and become trapped in the lungs; non-smokers much more readily exhale the radon particles.

The reality of the health risk involves a matrix of radon levels, duration and severity of exposure (a basement may exceed 4pCi/L, but do you spend most of your time there?), and cultural habits, such as being a smoker or a previous smoker.

The most recommended first step is to test your home's radon level and assess possible consequences. When buying or selling a home, a radon test should be an integral part of a home inspection. If the property had been tested by a previous owner, disclosure laws require that you receive that information. Results may lead you to press for corrective actions (radon mitigation) in your negotiations -- or levels may indicate that no action is required. County residents should take pride in the fact that Montgomery County is the only county in the country (there are 3,300 total) progressive enough to require the installation of a passive radon venting system in homes built after 1990.

Whether testing a home for sale or purchase, or testing your existing home, there are several things to keep in mind. You can pay a professional to conduct the test or purchase a do-it-yourself kit; cost and turnaround time is often a factor in this decision. Test kits can be purchased in home improvement centers around the County, or you can call the EPA's Radon Information Clearinghouse at 1-800-55RADON to find out about mail-order test kits. You can also contact DEP at 240.777.7757 for additional help. Costs will vary, but simple passive detectors using charcoal canisters and charcoal liquid scintillation devices, which must be mailed to or dropped off at a laboratory will cost as little as $10 and up.

Professional testing is also available, usually costing $80-$140, and should only be conducted by firms licensed through EPA's Radon Proficiency Program (RPP). A list of these firms is available through DEP. Professional testing can include continuous radon monitoring with active radon detectors to provide data over a longer test period, thereby eliminating some abnormally high test spikes, and providing a more reliable result.

Regardless of whether you do it yourself or turn to a radon professional, the Department of Environmental Protection strongly recommends that you consider testing your entire house to obtain more balanced results. Testing basement areas alone, for example, will not reflect your exposure risk in above ground living areas, such as second story bedrooms. Before spending $700-$1000 or more on mitigation work, you might want to test other levels and arrive at a weighted average, and then decide whether the risk potential is worth the extra investment.

It is essential to remember that radon levels should simply guide you to further rational choices, especially considering whether you smoke or not. If you have never smoked and your radon level is below 4pCi/L, your risk is equal to that of your chances of drowning; you may want to consider testing your home at a later date and taking some corrective action, but as you reach 2pCi/L, there is little you can do to reduce radon levels any further. On the other hand, a smoker with a reading of 4pCi/L is almost 15 times more likely to get lung cancer -- a risk approximately 100 times that of dying in an airplane crash; smokers may want to seriously consider fixing their home. Quitting smoking would also help, of course.

Test results between 4 and 10 should prompt non-smokers to conduct either a longer term test -- or short term test several months later. If still above 4, repairs are probably best indicated. Test results above 10 mean that you should have your home fixed as soon as possible. And remember that testing is best done during the winter months while windows, vents, and fireplaces are closed; winter levels are often 30-40 percent higher than warm weather readings.

Radon exposure is similar to many environmental health risks. There is a potential for a serious problem. Radon is real. But radon is also part of a natural process. By learning as much as you possibly can from reliable information sources about radon and radon exposure, you will be able to make a calm and informed decision about what steps you will need to take, if any. As DEP's Courville indicated, there is time to learn more and do more to ensure your health and that of your family, and of the "market" or "economic health" of your home.

top of page

The 1996 Safe Drinking Water Act Amendments required EPA to establish several new, health-based drinking water regulations. The first of these set requirements for microbial and disinfection byproducts.  The multimedia proposal for radon will be the second of these health-based drinking water regulations.

Breathing radon in the indoor air of homes is the primary public health risk from radon, contributing to about 20,000 lung cancer deaths each year in the United States, according to a landmark report this year by the National Academy of Sciences (NAS) on radon in indoor air. Radon is the second leading cause of lung cancer in the United States. Based on a second NAS report on radon in drinking water, EPA estimates that radon in drinking water causes about 168 cancer deaths per year, 89 percent from lung cancer caused by breathing radon released from water, and 11 percent from stomach cancer caused by drinking radon-containing water.

Radon Testing Devices - RadonTestKits.com
Illustrations and details on a variety of indoor air quality test kits, including radon-in-water and radon gas testing, with facts about radon in their environmental library and links to additional radon information.  Kits are available for purchase on-line.

Related links and documents

Guidelines for Radon Testing [21kb PDF]
Citizen's Guide to Radon
National Radon Proficiency Program

Residential Mitigation Providers
Individuals holding the Residential Mitigation Provider certification have demonstrated knowledge of radon mitigation techniques as applied to residential structures. Consumers are advised to verify experience, references, licenses, and skills for the nature of work to be performed. Certified radon mitigation service providers have also agreed to abide by local laws as well as the mitigation techniques detailed in the U.S. Radon Mitigation Standards.

Consumer's Guide to Radon Reduction:How to Reduce Radon Levels in Your Home
This booklet is for people who have tested their home for radon and confirmed that they have elevated radon levels.

Home Buyer's and Seller's Guide to Radon
This guide has been developed for anyone buying or selling a home who wants to learn about Radon.

A Citizen's Guide to Radon: The guide to protecting yourself and your family from radon.
This booklet was developed by the EPA, The U.S. Department of Health and Human Services and the U.S. Public Health Service. This is the complete guide to taking action to lower the radon level in your home. It offers strategies for testing and discussions of what steps to take after you have tested, discussions of  the risk of radon and radon myths. 

The National Environmental Health Association - National Radon Proficiency Program
Individuals holding the Residential Mitigation Provider certification have demonstrated knowledge of radon mitigation techniques as applied to residential structures. Consumers are advised to verify experience, references, licenses, and skills for the nature of work to be performed. Certified radon mitigation service providers have also agreed to abide by local laws as well as the mitigation techniques detailed in the U.S. Radon Mitigation Standards.

top of page