Radon Questions, Clearly Answered

Radon is a naturally occurring radioactive gas produced by the decay of uranium in soil, rock, and groundwater. It is colorless, odorless, and tasteless, which means it cannot be detected without proper testing equipment. Radon can accumulate in enclosed spaces like homes and buildings when it seeps up through the ground and enters through foundation cracks, gaps, or other openings.

Radon originates from the natural breakdown of uranium found in nearly all soils and rock formations. As uranium decays, it produces radium, which then decays into radon gas. This gas moves through soil and can enter buildings through the foundation. The amount of radon present depends on local geology, soil composition, and building characteristics.

Radon is classified as a Group 1 carcinogen by the World Health Organization and is identified by the EPA as the second leading cause of lung cancer in the United States after smoking. When radon gas is inhaled, radioactive particles can become trapped in the lungs and emit radiation that may damage lung tissue over time. This is why testing and mitigation are important considerations for property owners.

No. Radon is completely invisible, odorless, and tasteless. There are no physical symptoms that indicate radon is present in a building. The only way to determine whether radon exists in a specific location is through proper testing using calibrated equipment designed for radon detection.

Radon has been detected in homes throughout all 50 states and in countries around the world. While some geographic regions have higher average radon levels due to underlying geology, elevated radon can occur anywhere. The EPA recommends that all homes be tested regardless of geographic location, as radon levels can vary significantly from property to property even within the same neighborhood.

Metro Atlanta sits on geologic formations that include granite bedrock and clay-rich soils, both of which can contain uranium and produce radon. The region's geology, combined with building construction practices and seasonal weather patterns, contributes to radon accumulation in many area homes. However, radon levels vary by individual property, and testing remains the only reliable way to assess a specific home's radon concentration.

Long-term exposure to elevated radon levels increases the risk of developing lung cancer. When radon gas is inhaled, its radioactive decay products can lodge in lung tissue and emit alpha radiation, which may damage cells over time. The risk increases with higher radon concentrations and longer exposure durations. Health authorities including the EPA, CDC, and American Cancer Society recognize radon as a significant public health concern.

There is no known threshold below which radon exposure carries zero risk. The EPA recommends taking action to reduce radon levels at or above 4.0 pCi/L but also notes that radon levels below this threshold still carry some degree of risk. Some homeowners choose to mitigate even at lower levels to reduce potential exposure. The decision involves weighing individual circumstances and risk tolerance.

Radon is the primary cause of lung cancer among people who have never smoked, according to the EPA and American Cancer Society. Unlike smoking, which is a behavioral choice, radon exposure often occurs unknowingly in homes and workplaces. Because radon cannot be detected without testing, many people are exposed without awareness. This makes testing particularly important for identifying and addressing elevated levels.

Children may be more vulnerable to radon exposure for several reasons: they have higher respiratory rates, their cells are dividing more rapidly during growth, and they may have more years ahead during which radiation damage could potentially develop into health effects. While research is ongoing, many health organizations recommend that households with children give particular attention to radon testing and mitigation.

Yes. Radon exposure is a concern regardless of smoking status. In fact, radon is the leading cause of lung cancer among non-smokers. While smokers exposed to radon face compounded risk, non-smokers are not protected from the effects of radon exposure. Testing is recommended for all homes, regardless of the occupants' smoking history.

The only way to know whether your home has elevated radon levels is through testing. Because radon is invisible and odorless, there are no physical indicators of its presence. Testing can be performed using professional equipment or certified testing devices. The EPA recommends testing all homes, regardless of location or construction type.

Radon testing is the only method to determine actual radon levels in a specific property. Area averages and geological maps can suggest general radon potential but cannot predict the levels in any individual home. Because radon concentrations vary based on many factors—including soil conditions, foundation type, and building ventilation—testing provides the data needed to make informed decisions.

Professional radon testing typically involves placing calibrated continuous radon monitors in the lowest livable level of the home under closed-building conditions. These devices measure radon concentrations over a specified period and record data at regular intervals. After the testing period, results are analyzed and reported, providing an accurate assessment of radon levels during the test window.

Short-term radon tests typically require a minimum of 48 hours, though many professionals recommend 72-96 hours for more reliable results. Long-term tests, which provide a more comprehensive picture of annual average levels, are conducted over 90 days or more. The appropriate test duration depends on the purpose of the test and timing considerations.

Short-term tests measure radon levels over a period of 2-7 days and are commonly used for real estate transactions or initial screening. Long-term tests, conducted over 90 days or more, account for seasonal and daily fluctuations and provide a more accurate estimate of annual average exposure. Both types of tests have their appropriate applications depending on circumstances and objectives.

Yes. Radon levels can fluctuate based on weather conditions, seasonal changes, soil moisture, building ventilation, and modifications to the structure. A single test provides a snapshot of radon levels during that specific period. This is why periodic retesting is recommended, especially after major renovations, foundation work, or changes to HVAC systems.

The EPA recommends retesting every two to five years, even if initial results were low. Testing should also be repeated after significant home modifications, foundation repairs, or changes to heating and cooling systems. Properties with mitigation systems should be tested periodically to verify continued system performance.

Radon test results are reported in picocuries per liter (pCi/L), which measures the concentration of radon in the air. The EPA has established 4.0 pCi/L as the action level—the threshold at which mitigation is recommended. Results below this level still indicate some radon presence, and homeowners may choose to take action at any level based on their individual circumstances and risk considerations.

The EPA action level is 4.0 pCi/L (picocuries per liter). This is the radon concentration at which the EPA recommends homeowners consider mitigation. The EPA also notes that radon levels between 2.0 and 4.0 pCi/L still pose some risk, and homeowners may choose to reduce levels in this range as well. The action level represents a guideline, not a boundary between safe and unsafe.

No. There is no known radon level that carries zero risk. The EPA action level of 4.0 pCi/L is a recommended threshold for mitigation, not a safety guarantee. Levels between 2.0 and 4.0 pCi/L still present some degree of risk, and some homeowners choose to mitigate even at these lower concentrations. Risk assessment involves considering concentration levels, duration of exposure, and individual factors.

Radon levels can vary significantly between adjacent properties due to differences in soil composition, foundation construction, cracks or openings in the foundation, building ventilation, and other structural factors. Underground variations in uranium content and soil permeability can also differ over short distances. This variability is why each property requires individual testing rather than relying on neighborhood or regional averages.

Radon testing is commonly performed during real estate transactions to provide buyers and sellers with information about the property's radon levels. Many home inspectors include or offer radon testing as part of their services. Testing during a transaction allows parties to address elevated levels as part of negotiations and ensures that buyers have relevant information before completing the purchase.

Radon mitigation refers to the methods and systems used to reduce radon concentrations in buildings. The most common approach is active soil depressurization (ASD), which uses a vent pipe and fan to draw radon from beneath the building foundation and release it above the roofline where it disperses harmlessly. Other methods may be appropriate depending on building construction and site conditions.

An active soil depressurization system creates a pressure differential beneath the building foundation that prevents radon from entering the living space. A pipe is installed through the foundation slab or into the crawl space, and a fan draws air and radon from the soil and exhausts it above the roof. This continuous ventilation reduces radon accumulation inside the building.

Mitigation systems are designed to reduce radon levels significantly, but they do not eliminate radon entirely. The goal is to lower indoor concentrations to acceptable levels, typically below the EPA action level of 4.0 pCi/L and often much lower. Some residual radon will always be present, as it occurs naturally in the environment. Post-mitigation testing confirms the reduction achieved.

Properly designed and installed radon mitigation systems typically reduce indoor radon levels by 80-99%. Most systems successfully lower radon concentrations well below the EPA action level. Effectiveness depends on proper system design, installation quality, and ongoing maintenance. Post-mitigation testing is essential to verify that the system is performing as intended.

Most residential radon mitigation systems can be installed in one day, typically requiring 3-5 hours of work. More complex installations—such as those involving multiple foundation types, large buildings, or challenging access conditions—may require additional time. Commercial installations vary based on building size and complexity.

Radon mitigation systems include visible components—typically PVC piping that runs from the foundation to above the roofline, and an inline fan. Installers work to minimize visual impact by routing piping through closets, garages, or along exterior walls where feasible. The fan produces a low, continuous hum similar to a bathroom exhaust fan, which most occupants find unobtrusive.

A professionally installed radon mitigation system demonstrates that the property has been addressed for radon and provides documented protection. This can be viewed favorably by buyers and may facilitate real estate transactions. Conversely, unaddressed elevated radon levels may raise concerns during home sales. The presence of a functioning system provides assurance that radon has been managed.

Post-mitigation testing is strongly recommended to verify that the system has successfully reduced radon levels. Testing is typically performed 24-48 hours after installation and confirms the effectiveness of the mitigation approach. Without post-mitigation testing, there is no objective verification that the system is performing as intended.

Radon levels can increase after mitigation if the system fails, the fan stops working, or changes to the building affect system performance. Foundation settling, new cracks, or modifications to HVAC systems can also impact radon levels. This is why periodic retesting and system monitoring are recommended to ensure continued effectiveness.

Radon mitigation fans typically have a lifespan of 5-15 years, depending on the fan model and operating conditions. The piping and other passive components of the system can last much longer with proper installation. Regular monitoring and timely fan replacement help ensure continuous radon reduction over the long term.

Radon mitigation systems require minimal maintenance but should be monitored regularly. Most systems include a manometer or indicator that shows whether the fan is operating. Homeowners should periodically check this indicator and listen for fan operation. Professional inspection every few years can identify potential issues before they affect system performance.

If post-mitigation testing shows radon levels remain elevated, additional measures may be needed. This could include adding suction points, sealing additional entry points, adjusting fan capacity, or addressing other factors affecting system performance. A qualified radon professional can assess the situation and recommend appropriate modifications.

Radon testing requirements during real estate transactions vary by state and locality. In Georgia, radon testing is not universally mandated by law, but it is commonly requested by buyers and may be required by certain lenders. Many real estate professionals recommend testing as part of the due diligence process, and it is increasingly standard practice in the Metro Atlanta market.

Payment responsibility for radon testing and mitigation is typically negotiated between buyers and sellers as part of the real estate transaction. In some cases, sellers may test proactively before listing; in others, buyers request testing during the inspection period. Mitigation costs, if needed, may be paid by either party or shared, depending on the terms of the purchase agreement.

The EPA recommends radon testing in all buildings where people spend significant time, including commercial and institutional facilities. Schools, daycare centers, office buildings, and other commercial properties can have elevated radon levels. Testing allows building owners and managers to assess radon conditions and take appropriate action to protect occupants.

Schools and daycare facilities can have elevated radon levels, particularly in ground-floor and below-grade spaces. Because children may be more vulnerable to radon exposure and spend considerable time in these facilities, testing is particularly important. The EPA has established guidelines specifically for radon testing in schools, and many states have programs addressing radon in educational settings.

Radon test results can influence property transactions by providing information that affects buyer decisions and negotiation terms. Elevated radon levels may lead to requests for mitigation or price adjustments. Having a functioning mitigation system or documentation of low radon levels can facilitate transactions by addressing potential buyer concerns proactively.

Professional radon testing costs are generally modest relative to the information provided and the value of the property being assessed. Costs vary based on the type of test, testing duration, and whether it is part of a broader home inspection. Given the potential health implications of undetected elevated radon, testing represents a reasonable investment in property assessment and occupant safety.

The decision to mitigate depends on radon levels, individual risk tolerance, and circumstances. For properties with radon at or above the EPA action level of 4.0 pCi/L, mitigation is recommended to reduce potential health risks. Many property owners also choose to mitigate at lower levels for additional peace of mind. Mitigation provides ongoing radon reduction and may facilitate future property transactions.

While DIY radon mitigation is possible, professional installation is recommended to ensure the system is properly designed and effectively reduces radon levels. Improper installation can result in inadequate radon reduction, wasted resources, or other issues. Professional installers have the training, equipment, and experience to assess site conditions and implement appropriate solutions.

If you are uncertain about testing or mitigation, consider that testing is a low-cost, non-invasive way to obtain factual information about your property. Results provide the basis for informed decision-making. If test results show elevated levels, you can then evaluate mitigation options based on actual data rather than uncertainty. Many professionals offer consultations to help property owners understand their options.

Area averages and geological data provide general information about regional radon potential but cannot predict levels in any specific property. Radon concentrations vary significantly based on individual building characteristics, soil conditions, and other factors. Professional testing provides accurate, property-specific data that reflects actual conditions in your home or building.