What is It?
Radon is a naturally occurring colorless, odorless, tasteless, inert, highly radioactive gas that emits alpha radiation. It is the heaviest of all known gases and nine times heavier than air. It is produced by the natural breakdown (radioactive decay) of the element uranium and can be found in igneous rock, soil, sand and water in which it is soluble. The molecular structure of radon is such that it easily penetrates many common materials: paper, leather, low density plastic (like plastic bags, etc.) most paints, and building materials like gypsum board (sheetrock), concrete block, mortar, sheathing paper (tarpaper), wood paneling, and most insulation materials.
Without getting too technical, there are several isotope forms of radon. But the two that are of the most concern to us are radon 222 and radon 220 because these are the isotopes most often found in significant concentrations in our environment: 69.3% in soil around and under a house, 18.5% in well water, 9.2% in outdoor air, 2.5% in building materials and 0.5% in public water supplies. Radon has been discovered in all 50 states and the levels of concentration vary from state to state and region to region. To find the radon levels in your state and local area go to, www.radon.com/radon/radon_map.html.
Radon seeps from soil and rocks through cracks or holes in the foundation of homes and buildings and into the air where it enters the human body through inhalation. Radon can also be ingested by drinking and cooking with water containing radon, although the radon in water is more harmful to human health when it is released into the air by showering or cooking and inhaled. Some building materials like wood paneling and sheetrock also release radon into the air. Every home, school and office building can be invaded by radon whether old, new, airtight or drafty and with or without a basement. Common home entries are:
- Cracks in solid floors
- Construction joints
- Cracks in walls
- Gaps in suspended floors
- Spaces around service pipes
- Cavities inside walls
- The water supply
Risks of Exposure to Radon
If you are wondering why levels of radon should be important to you, it is because radon is an established carcinogen. In fact, the EPA (Environmental Protection Agency) estimates that as many as 20,000 deaths a year can be attributed to radon-induced lung cancer, securing radon’s second place position as a cause of lung cancer, and at a price tag of $2 billion plus dollars per year in health care costs. Nearly 1 out of every 15 homes in the U.S. is estimated to have elevated radon levels according to the EPA.
Congress passed the Indoor Radon Abatement Act of 1988 (IRAA). The IRAA established the long-term goal of making indoor air as free from radon as the ambient air outside buildings. For the last two decades, the EPA, in an effort to meet the IRAA’s goal, has overseen a voluntary program to promote radon awareness and testing, to introduce new radon-resistant construction techniques to the building industry and to install radon mitigating systems in homes with elevated levels of radon.
So how are we doing, you wonder? Not so good, unfortunately. In 2008, the Office of the Inspector General reported that from 2001 to 2005 about 469,000 new single-family homes out of 6.7 million were constructed with radon-reducing features. Further, approximately 2.1 million existing single-family homes out of 76.1 million had radon-reducing features in place.
What is an Inspection for Radon?
In reality, there is no such thing as a radon inspection. Rather, if you want to know the radon level in your home, you can use either a short-term test and testing kit or a long-term test and testing kit. Experts recommend the short test first. If levels are at or above the standard set, then a second measurement can be taken with either a short- or long-term test. These tests are simple to undertake and can be completed by the homeowner, a home inspection company or a professional radon tester.
Before you begin a radon test, it is important to understand several characteristics of radon. Radon levels can change from day to day and season to season depending on the weather, the amount of ventilation in a home or building and the levels of heat and humidity. Indoor levels of radon are highest during the heating season and erratic during severe weather and high winds. These typical fluctuations mean that even if a home or building passes a radon test one year, it cannot be assumed that in the future the level will remain the same unless a radon mitigation system is in place. For this reason, the EPA recommends periodic testing at least every two years or as required or recommended by your state or local authority. Also, if your home or building is extensively renovated or remodeled, retesting is recommended.
The short-term test is the simplest and quickest. Test kits are placed in the lowest level of a building or home from 2-90 days, depending on the device used, but for no less than 48 hours. Windows and doors should be closed 12 hours before beginning the test and during the testing period itself. To avoid inaccurate results, testing should not be done in kitchens, bathrooms or hallways or in humid or drafty areas. Also, it is important not to touch or move the device once positioned or the results may be erroneous.
Short-term testing devices can be passive-requiring no energy to function-or active devices. Examples of passive devices are: alpha track detectors, charcoal canisters, charcoal liquid scintillation detectors and electret ion chamber detectors. Active devices are power-driven and include several types that continuously monitor radon levels. These devices furnish data on the variation in radon levels during the testing period and some can even detect interference. Active devices are best used by professional testers and are more expensive than passive devices. Charcoal canisters (short-term, passive devices that test levels 2 to 4 days) are the most widely used and can be purchased in hardware and drug stores, over the Internet, from some laboratories or through the National Safety Council’s Radon Hotline (800-767-7236). When the test is completed, the canisters are sent to a laboratory for analysis.
Long-term testing devices are used for more than 90 days and are more likely to reflect a yearly average level of radon than a short term test. With any test, the closer the measurement is to 365 days, the more accurate the annual average radon level result is. Devices can be ordered through the Safety Council’s Radon Hotline (800-767-7236. A long term test is recommended if a short term test indicates a level of radon at or above the acceptable threshold. If the long-term test validates higher than acceptable levels, the EPA strongly advises steps be taken to correct the problem.
Who Needs to Test for Radon?
Every building in which people work, go to school or reside should be checked for radon. Just because your neighbor’s home is radon-free doesn’t mean yours is. When you consider the amount of time people spend in office buildings and children spend in schools, it makes sense to have these facilities tested for radon as well because the cumulative effect of radon exposure at school and home or work and home may provide more than the recommended exposure. In fact, one nationwide survey estimated that one in five schools have at least one schoolroom with a radon level that exceeds the action level (the level at which the EPA recommends steps be taken to reduce the level of radon); this amounts to an estimated 70,000 schoolrooms across the country with high radon levels.
How Are Test Results Interpreted?
When the testing period is over, the canisters or other testing device is sent to a laboratory. The results are usually ready in about a week. The laboratory will send a report back to the tester which will indicate the level of radon in picocuries per liter (pCi/L) of air, the standard by which radon is measured. The EPA has stated that no level of radon is safe and that any exposure carries some risk. However, the agency has set a threshold of 4 picocuries as the level above which some sort of action to remove radon is strongly recommended. There is a stated protocol of what to do if high levels are detected based by the laboratory. In some cases, a repeat test is suggested; in others immediate remediation (ridding the air of radon) is recommended. For a complete explanation of which levels require retesting or remediation, visit the EPA’s site, www.epa.com.
How Do I Get Rid of Radon?
Before you begin to test or remediate radon in your home, contact your state radon program to find out if there are particular requirements for testing or remediation that you should know about. Online information can be obtained at the EPA’s website, www.epa.gov/radon/whereyoulive.html. Some states maintain lists of qualified radon service professionals who test or mitigate and some have proficiency programs to certify testers and mitigators.
If the results of your test indicate a level at or above 4 picocuries, you will want to rid your home of radon by hiring a radon removal specialist. (This is not a job you want to tackle yourself because it does require technical expertise.) Your radon contractor will select the system or systems most appropriate for your particular home from a number of different methods or use some combination of methods to get the job done. The method selected will depend on your radon level, the source of the radon (air only or both air and water), the construction of your home, foundation type (basement, slab-on-grade or crawl space), size of your home, the climate in which you live, diagnostic tests that your contractor may need to perform and the cost of installation and operation.
There are two ways to rid your home of radon: prevent it from entering in the first place or remove it after it has entered. The EPA recommends preventing entry. The most commonly used system for preventing radon from entering your home is a soil suction system. Put simply, this system draws radon from below your house and vents it through a pipe or pipes to the outside air where it is rapidly diluted.
The cost of radon reduction depends on the system used, tax, and the necessity for any needed diagnostic tests or permits. Generally the cost can range from $800 to $2,500 depending on the type of system selected. The average cost is $1,200.
When selecting a mitigation professional, the same rules apply as with any other contractor. Obtain three written estimates, check professional licenses, liability insurance, credentials, references and read all the fine print on the contract. The contract itself should contain the standard contract elements: total cost, the amounts of any deposits and payment schedules, a time line for completion, how damage and clean-up will be handled, etc. A radon mitigation contract should also include three additional radon-specific elements:
- A guarantee to reduce radon below a negotiated level
- Details of any warranties or optional features that come with the system
- Warranties or guarantees that are transferable if your home is sold.
When you discuss your radon system with your contractor, you will want to ask:
- Are there any warning devices (alarms, lights, gauges) that will alert you to system mal-function and will they be placed where you can easily monitor them?
- Will the contractor do a post-installation test for radon no sooner than 24 hours after the system is up and running (with fan on if there is one) and no later than 30 days post-installation?
- Will you receive a written explanation of how the system operates and what is involved in maintenance?
Your contractor should agree to return for a follow-up test during the first year your system is in place. However, it is wise to also have a second retest by an independent contractor to avoid a potential conflict of interest and to ensure accuracy. This is also true if there is a system malfunction. Always retest after any repairs are made.
The Bottom Line
At certain levels of exposure, radon is a silent killer. Are you and your family protected?
