Radon is a naturally occurring radioactive gas formed from the breakdown of uranium in soil, rock, and water. This invisible, odorless, and tasteless gas can seep into homes and buildings, accumulating to harmful levels indoors. Understanding radon’s presence is important because it is linked to an increased risk of lung cancer, making it a concern for indoor air quality. Addressing radon exposure involves recognizing its source and understanding its health impact.
Understanding Radon and Its Origin
Radon originates from the decay of uranium, an element found in most soils, rocks, and groundwater. As uranium breaks down, it forms radium, which then decays into radon gas. The gas is continually produced in the ground and migrates upwards through the soil.
Radon can enter buildings through various openings in the foundation, such as cracks in concrete slabs, floor-wall joints, utility penetrations, sump pump openings, and floor drains. Because uranium is present in varying concentrations across all 50 states, any home, regardless of its age or construction type, has the potential to accumulate elevated radon levels.
How Radon Causes Lung Cancer
When radon gas decays, it emits radioactive particles. These decay products can attach to dust and other airborne particles, which are inhaled and become trapped in the lungs, where they continue to decay.
This ongoing decay releases alpha particles that can damage the DNA within lung cells. This damage can disrupt normal cell growth, potentially leading to uncontrolled cell division and lung cancer. Prolonged exposure to elevated radon levels significantly increases a person’s risk of developing this disease.
Radon is recognized as the second leading cause of lung cancer overall, and it is the primary cause among non-smokers. The U.S. Environmental Protection Agency (EPA) estimates that radon exposure contributes to approximately 21,000 lung cancer deaths annually in the United States. A concerning aspect of radon exposure is that it produces no immediate symptoms, meaning individuals may be unknowingly exposed to high levels for extended periods without any indication.
Detecting Radon in Your Home
Since radon is colorless, odorless, and tasteless, testing is the only reliable way to determine its presence and concentration in a home. Several testing methods measure radon levels. Short-term tests, such as charcoal canisters or alpha track detectors, are used for 2 to 90 days.
Long-term tests, which include alpha track detectors or electret ion chambers, provide a more accurate average radon level over a period exceeding 90 days. For accurate results, test kits should be placed in the lowest lived-in area of the home, away from drafts, high heat, or high humidity. Radon levels are commonly measured in picocuries per liter (pCi/L), and the EPA recommends taking action to reduce radon when levels are at or above 4 pCi/L. Professional testing services are also available and can provide expert assessment and analysis.
Strategies for Radon Reduction
When a home has elevated radon levels, various mitigation techniques can effectively reduce the concentration. The most common and effective method is sub-slab depressurization. This system involves installing a pipe through the foundation floor, connected to a fan that draws radon gas from beneath the house. The collected radon is safely vented outdoors, typically above the roofline.
Other methods include sealing cracks and openings in the foundation to block entry points. Improving general ventilation within the home, or utilizing heat recovery ventilators (HRVs), can also help dilute indoor radon concentrations. It is important to hire qualified, certified radon mitigation professionals for these installations. Organizations like the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB) certify professionals who adhere to specific standards for radon reduction. Following mitigation, conducting a follow-up test is important to confirm the system’s effectiveness in lowering radon levels.