Radon

Frequently Asked Questions:

What is radon?

Radon is a naturally occurring, invisible, odorless, tasteless gas that is dispersed in outdoor air but can reach harmful levels when trapped in buildings. Exposure to radon increases the risk of lung cancer. Radon is the second leading cause of lung cancer in the U.S. (behind smoking) and the leading cause of lung cancer among non-smokers. The U.S. Environmental Protection Agency (EPA) estimates that radon is responsible for more than 20,000 lung cancer deaths per year.

Is radon common in St. Joseph County?

One in four homes in St. Joseph County contains unsafe levels of radon. That level is much higher than the national average of one in fifteen homes and underscores why testing your home for radon is critical.

How does radon get into a building?

When radon or other gases rise through soil or rock, it gets trapped inside, builds up pressure, and becomes concentrated. Because the air pressure inside a home is usually lower than in the soil, the higher pressure under the building forces the gas through floors and walls and into the home. Openings that are common pathways for radon include:

• Cracks in floors and walls
• Gaps in suspended floors
• Openings around sump pumps and drains
• Cavities in walls
• Joints in construction materials
• Gaps around utility penetrations (pipes and wires)
• Crawlspaces that open directly into the house

While high radon levels may be more common in some geographic areas, any home might have an elevated radon level. New and old homes, well-sealed and drafty homes, and homes with or without basements all can have a radon problem. Homes below the third floor of a multi-family building are particularly at risk.

What is the acceptable level for radon in a building?

The EPA states that any radon exposure carries some risks. However, the EPA recommends that radon be mitigated in homes if an occupant's long-term exposure will average 4 picocuries per liter (pCi/L) or higher.

How can I discover the radon level in my house?

Anyone can use a single-use "do-it-yourself" test kit to check their home. Simple to use and relatively inexpensive, you can find these kits in hardware stores and other retail outlets, local health departments, and county extension offices. They are also available through the Internet. St. Joseph County is starting a program where we will test eligible homes at no cost to the homeowner and may assist in providing a radon mitigation system if necessary. You can request assistance to see if you qualify for this program or email us at radon@sjcindiana.gov.

The EPA recommends testing for radon in the home's lowest level suitable for occupancy, as this typically is where the highest radon level may occur. Ideally, the test should be conducted in a regularly used room on that level, such as a living room, playroom, den, or bedroom. Avoid testing in a kitchen, bathroom, laundry room, or hallway because high humidity and drafty conditions can bias the results from some test devices.

Place the testing devices out of the way and do not disturb them while they are sampling. Doing so may alter their results. If the lowest occupied level is not used much, consider testing a higher-use area. Testing more rooms and for more extended periods may help you more accurately estimate your long-term exposure. Because most indoor radon comes from naturally occurring radon in the soil, high indoor levels are more likely to exist below the third floor. That is why the EPA recommends testing all homes below the third floor. In some cases, however, high radon levels have been found at or above the third floor due to radon movement through elevators or other airshafts in the building. If you are concerned about this possibility, consider testing for radon on the upper floors.

What health effects are associated with radon exposure?

Radon is identified as the second leading cause of lung cancer in the United States, behind smoking. Like other indoor air contaminants, studies suggest that children are at greater risk than adults from radon exposure because their metabolism is higher, and they have more years ahead of them to contract adverse long-term effects.

Only smoking causes more cases of lung cancer. If you smoke and are exposed to elevated radon levels, your risk of lung cancer is exceptionally high.

Radon gas decays into radioactive particles that can get trapped in your lungs when you breathe. As they break down or decay, these particles release small bursts of energy that can damage lung tissue and lead to cancer throughout your lifetime. Not everyone exposed to elevated levels of radon will develop lung cancer, and the amount of time between exposure and the onset of the disease may be many years.

How is radon removed from a building?

The design of your house will affect the kind of radon-reduction system that will work best. Houses are generally categorized according to their foundation design — for example, basement, slab-on-grade (concrete poured at ground level), or crawlspace (a shallow unfinished space under the first floor). Some houses feature more than one foundation design. For instance, it is typical to have a basement under part of the house and a slab-on-grade or crawlspace under the rest. In these situations, a combination of techniques may be needed to reduce radon levels to below 4 pCi/L.

There are several methods that a contractor can use to lower radon levels in your home. Some techniques prevent radon from entering your home, while others reduce radon levels after it has entered. The EPA generally recommends methods that prevent the entry of radon. In many cases, simple systems using underground pipes and an exhaust fan may be used to reduce radon. Such systems are called "sub-slab depressurization" and do not require significant changes to your home. These systems remove radon gas from below the concrete floor and the foundation before it can enter the home. Similar systems can also be installed in houses with crawlspaces.

Whether these systems are suitable for your home will depend on its design and other factors. Radon contractors have several options for selecting the best method for your home.

Sealing cracks and other openings in the floors and walls is a fundamental part of most approaches to radon reduction. Sealing does two things: it limits the flow of radon into your home and reduces the loss of conditioned air, thereby making other radon reduction techniques more effective and cost-efficient. The EPA recommends against the use of sealing alone to reduce radon. By itself, sealing has not been shown to lower radon levels significantly or consistently, in part because entry points are difficult to identify and permanently seal. Normal settling of your house will create new entry routes and reopen the old ones.

Any information you have about your house's construction could help your contractor choose the best mitigation system. To design the system, the contractor will start by visually inspecting your house. If this inspection fails to provide enough information, the contractor will need to perform diagnostic tests to help develop the best radon reduction system for your home. The need for diagnostic tests will be determined by details specific to your house, such as the foundation design and what kind of material is under your house, as well as by the contractor's experience with similar houses and similar radon test results.