What Is Radon Gas?
Radon gas is a naturally occurring radioactive gas that is invisible, odorless, and tasteless. It originates from the radioactive decay of uranium, which is commonly found in soil, rock, and water. As uranium breaks down, it forms radium, which then decays to produce radon gas. This gas can seep into homes and buildings through cracks in foundations, floor drains, sump pits, and other openings.
How Does Radon Enter Your Home?
Radon enters homes primarily through the soil beneath the structure. The pressure inside a house is typically lower than the pressure in the soil surrounding the foundation. This difference in pressure acts like a vacuum, drawing radon gas from the ground into the building. Common entry points include:
Cracks in solid foundations: Even microscopic cracks can allow radon to pass through.
Construction joints: Where the foundation walls meet the floor slab, gaps can exist.
Sump pits: These open pits, often used for water removal, provide a direct pathway.
Floor drains: Unsealed or seldom-used drains can be entry points.
Pores and tiny cracks in hollow-block walls: These porous materials can allow gas to diffuse through.
Water supply: Radon can also enter homes through well water, particularly if the water source is from an underground aquifer in an area with high uranium content. When this water is used for showering, washing dishes, or other activities, the radon can off-gas into the air.
Health Risks Associated with Radon Exposure
The primary concern with radon exposure is its potential to cause lung cancer. When radon gas decays, it releases tiny radioactive particles. When inhaled, these particles can damage the cells lining the lungs. Over time, this damage can lead to the development of lung cancer. The Environmental Protection Agency (EPA) estimates that radon is responsible for about 21,000 lung cancer deaths each year in the United States, making it the second leading cause of lung cancer after smoking. For smokers, the risk of lung cancer from radon exposure is significantly higher.
Who is at Risk?
Everyone is at risk of radon exposure, as it can be found in any home, new or old, with or without a basement. However, individuals who spend a lot of time in basements or ground-level rooms are at a higher risk due to potentially higher radon concentrations in those areas.
Testing for Radon
Since radon is invisible, odorless, and tasteless, the only way to know if your home has elevated levels is to test for it. Radon testing is relatively inexpensive and easy to do.
Types of Radon Tests
There are two main types of radon tests:
Short-term tests: These tests measure radon levels for 2 to 90 days. They are often used for an initial screening. Charcoal canisters, alpha track detectors, and electret ion chambers are common types of short-term devices. These tests are typically placed in the lowest lived-in area of the home for a specified period and then sent to a lab for analysis.
Long-term tests: These tests measure radon levels for more than 90 days, typically for several months up to a year. Long-term tests, such as alpha track detectors, provide a more accurate average of your home's radon level because radon levels can fluctuate daily and seasonally.
When to Test
It is recommended to test your home for radon:
Every two years, even if previous tests showed low levels.
After any major renovations or structural changes to your home.
Before buying or selling a home. Many real estate transactions now include radon testing as a standard contingency.
If you live in an area known to have high radon levels.
How to Conduct a Test
Most radon test kits can be purchased online or at local hardware stores. Follow the instructions carefully for proper placement and duration. For accurate results, it's crucial to:
Close all windows and exterior doors for at least 12 hours before and during the short-term test.
Place the test kit in the lowest lived-in area of your home, at least 20 inches above the floor.
Avoid placing the test kit near drafts, heat sources, or in direct sunlight.
Do not disturb the test kit during the testing period.
For more reliable results, especially in real estate transactions, it is often recommended to hire a qualified radon professional to conduct the testing.
Understanding Radon Levels
Radon levels are measured in picocuries per liter (pCi/L). The EPA recommends taking action to reduce radon levels if the concentration is 4 pCi/L or higher. However, it's important to note that no level of radon is considered completely safe. The EPA also recommends considering mitigation if levels are between 2 pCi/L and 4 pCi/L.
Radon Mitigation
If your home tests reveal elevated radon levels, there are effective methods to reduce the concentration. This process is called radon mitigation. The most common and effective method is active soil depressurization (ASD).
Active Soil Depressurization (ASD)
ASD involves creating a vacuum beneath the foundation of your home to draw radon gas from the soil and vent it safely outside. This is typically done by:
Installing a suction pit: A small hole is dug in the concrete slab of the basement or lowest level.
Inserting a PVC pipe: A sealed PVC pipe is inserted into the suction pit, extending through the house and typically out through the roof.
Attaching a fan: An inline fan is connected to the pipe, creating continuous suction that pulls radon gas from the soil beneath the foundation and vents it above the roofline, where it dissipates harmlessly into the atmosphere.
Other mitigation techniques include:
Sealing cracks and openings: While not a standalone solution, sealing major cracks and openings in the foundation can complement ASD systems by preventing additional radon entry.
Sub-membrane depressurization: Used for homes with crawl spaces, this involves covering the crawl space floor with a high-density polyethylene sheet and creating a vacuum beneath the membrane to draw out radon.
Drain tile depressurization: If the home has an existing drain tile system (a system designed to collect and divert groundwater away from the foundation), it can sometimes be used to effectively depressurize the soil.
Heat recovery ventilators (HRVs) or energy recovery ventilators (ERVs): These systems exchange indoor air with outdoor air, which can help dilute radon levels. However, they are generally less effective than ASD for high radon concentrations.
Hiring a Qualified Professional
Radon mitigation is a complex process that should be performed by a qualified professional. A certified radon mitigation contractor will assess your home's specific characteristics, design a suitable system, and install it properly to ensure effective radon reduction. It's crucial to hire a contractor who is certified by a recognized program, such as the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB).
Radon and Real Estate
Radon testing has become a significant factor in real estate transactions. Many homebuyers now request radon testing as part of their home inspection process. If elevated radon levels are found, it can become a point of negotiation, with sellers often agreeing to pay for mitigation as a condition of sale. This protects both the buyer and seller, ensuring a safer living environment.
Government and Public Health Initiatives
Many government agencies and public health organizations are actively involved in raising awareness about radon and promoting testing and mitigation. The EPA provides extensive resources, guidelines, and recommendations for homeowners. State and local health departments often offer information, subsidized test kits, and lists of certified professionals. The goal of these initiatives is to reduce the public's exposure to radon and prevent radon-induced lung cancer.
Conclusion
Radon gas is a silent killer, but its dangers can be easily managed. Understanding what radon is, how it enters homes, and the health risks it poses is the first step. Regular testing is crucial, and if elevated levels are found, effective mitigation techniques are available. By taking proactive steps to test and mitigate radon, homeowners can significantly reduce their risk of lung cancer and create a safer living environment for themselves and their families. Don't wait for symptoms to appear; test your home for radon today.
