Why Radon Testing Is Essential: Complete Guide for Homeowners & Buyers

Radon is a radioactive gas that forms naturally when uranium in soil and rock breaks down. This process has been happening for billions of years. The difference today is that we live in tightly sealed buildings that can trap radon inside, allowing it to accumulate to dangerous concentrations.

The gas enters homes through cracks in foundations, gaps around pipes, sump pits, and any other opening that connects your living space to the soil below. Once inside, radon can build up to levels hundreds of times higher than outdoor air.

What makes radon particularly dangerous is its radioactive decay. As radon breaks down, it releases tiny radioactive particles that, when inhaled, can damage lung tissue and lead to cancer over time. Unlike cigarette smoke, which provides obvious warning signs, radon exposure accumulates silently over years or decades.

The health effects of radon exposure are well documented. The World Health Organization, the American Cancer Society, the EPA, and medical organizations worldwide agree: radon causes lung cancer.

According to the EPA, radon is responsible for about 21,000 lung cancer deaths each year in the United States. To put that in perspective, that is more than the number of Americans killed annually in drunk driving accidents, house fires, drownings, and falls combined.

What many people do not realize is that radon is the leading cause of lung cancer among people who have never smoked. If you have never touched a cigarette but develop lung cancer, there is a strong chance radon played a role.

Buying a home is one of the biggest decisions you will ever make. A radon test should be a non-negotiable part of that process, right alongside the home inspection, termite inspection, and other standard evaluations.

Real estate transactions provide the perfect opportunity to address radon for several reasons. First, you have negotiating leverage. If testing reveals elevated levels, you can ask the seller to install a mitigation system or reduce the price to cover the cost. Second, you are already conducting inspections, so adding radon testing is a natural fit. Third, you want to move your family into a safe environment from day one.

Many home inspectors include radon testing as an add-on service. However, some buyers prefer to hire a dedicated radon testing company to ensure the most accurate results. Either approach works as long as the testing follows EPA protocols.

There are two main approaches to radon testing: professional testing using continuous radon monitors (CRMs) or do-it-yourself testing with charcoal or alpha track detectors. Both can provide useful information, but they have important differences.

For real estate transactions, professional testing is strongly recommended. The continuous monitoring capability catches any attempts to manipulate results by opening windows or doors, and the calibrated equipment provides the accuracy needed for such an important decision.

For homeowners who want to check their home periodically, DIY kits can be a cost-effective starting point. If a DIY test shows elevated levels, follow up with professional testing before making decisions about mitigation.

Radon is measured in picocuries per liter of air (pCi/L). The EPA has established 4 pCi/L as the "action level," the point at which they recommend taking steps to reduce radon in your home. However, the EPA also notes that no level of radon is completely safe, and they recommend considering mitigation for levels between 2-4 pCi/L.

The average indoor radon level in the United States is about 1.3 pCi/L. The average outdoor level is about 0.4 pCi/L. If your home tests above 4 pCi/L, you should take action. Many professionals recommend considering mitigation at 2 pCi/L or higher, especially if you have risk factors like spending significant time in the lowest level of your home or having smokers in the household.

While any home can have elevated radon, certain factors increase the likelihood. Understanding these factors helps you assess your home's risk profile, though testing remains the only way to know for certain.

One common misconception is that new homes are safe from radon. In fact, modern construction techniques that make homes more energy-efficient can actually increase radon levels by reducing natural ventilation. New homes need testing just as much as older ones.

Protecting your family from radon is straightforward once you understand the process. Here is what to do: