Q&A

National Radon Defense Q&A

Are radon levels higher in the winter?

Not always. Researchers estimate that the same negative effects are likely due to the increased exposure time in the home. Additionally, because the home is sealed, the colder months can produce higher radon levels. The same applies to a home closed in the summer because of air conditioning.

Can a radon fan be installed in the basement?

No and Yes, depending on if you live in the US or in Canada. In the US Radon Fans Don't Belong in the Basement. Most improper systems have the Radon fan in the basement or some other livable space in the house. This is a huge problem, and totally against EPA standards. It's easier to install a system like this, and it will get rid of the Radon in the basement.

In Canada, however properly installed fans and pipes will not leak radon into the building and are usually installed in the basement. When the fan and pipe are placed inside the home and combined with a ground level discharge, almost the entire system is located indoors, which helps to avoid problems that can arise from cold climates.

Can homes without basements have radon?

Yes. The style of the home has very little to do with radon entry.

Can I reduce radon by opening the windows in the basement or lower level?

Not really, you can temporarily reduce the radon levels simply by opening windows. This is not a permanent solution to reducing the radon levels in the home. 

Can I test for radon myself?

Yes, you can do the radon test yourself. Reliable test kits are available from qualified radon testers and companies. Reliable testing devices are also available by phone or mail-order and can be purchased in hardware stores and other retail outlets. Do it yourself kits can cost less than $25.

Can radon be reduced simply by sealing crack and slab openings?

No. Reducing the radon levels in a home by sealing cracks or a sump pit has not proven to be very effective.  This is partially due to the radon levels in the soil building up to a higher concentration when the openings are sealed so that less soil air comes in but it comes in with a higher radon concentration.  Sealing is still a necessary component of sub-slab depressurization radon mitigation systems.

Can Radon cause cancer?

Yes! Radon decays quickly, giving off tiny radioactive particles. When inhaled, these radioactive particles can damage the cells that line the lung. Long-term exposure to radon can lead to lung cancer, the only cancer proven to be associated with inhaling radon.

Can radon come from the sump pump or pit?

Yes. Radon is a gas that enters your building from the soil beneath and around your house. These gases can enter your home through the footing drain tile that is connected to the sump pump in your basement. 

Do I have to seal my crawl space to reduce the radon levels?

Yes. Since most crawl spaces have dirt floors and radon is found in the soil, sealing or encapsulating the crawl space is important to reduce the radon levels.

Do I need to test for Radon if I have a new home?

Yes, you still need to test. House construction can affect radon levels. However, radon can be a problem in homes of all types: old homes, new homes, drafty homes, insulated homes, homes with basements, homes without basements. Local geology, construction materials, and how the home was built are among the factors that can affect radon levels in homes.

Do I need to test my home for radon if my neighbor's test results were good?

Yes, you still need to test. Radon levels can vary greatly from home to home. The only way to know if your home has a radon problem is to test it.

Do I need to test my water for radon?

Although radon gets into some homes through water, it is important to first test the air in the home for radon. If your water comes from a public water system that uses groundwater, call your water supplier. High radon levels from public water sources are extremely rare. If you get your water from a private well, we recommend you test your water. 

Do I really need to test for radon if I have lived in my house for a long time and no one has gotten sick?

Absolutely, you need to test. You will reduce your risk of lung cancer when you reduce radon levels, even if you've lived with a radon problem for a long time.

Do radon levels increase with the age of a home?

No. The only way to know the radon level in any home, regardless of its age, foundation type, heating system, air tightness, or building materials, is to conduct a test. Elevated radon has been found in brand new homes and homes over 150 years old.

Does radon in drinking water pose a risk?

No, in most cases, radon entering the home through water will be a small source of risk compared with radon entering from the soil. The Environmental Protection Agency (EPA) estimates that indoor radon levels will increase by about 1 pCi/L for every 10,000 pCi/L of radon in water. Only about one to two percent of indoor radon in air comes from drinking water.

Does radon increase in the winter?

Great question! Cold weather in the winter affects radon levels. Cold weather increases the amount of warm air that is escaping from your house through vents or drafty windows. ... This stack effect can be greater in the winter months resulting in more gas entering the home.

Does rain affect radon testing?

It can. Certain types of weather can have a greater impact on your home's radon levels. Wind and rain storms create the largest variables of radon levels when testing for radon gas. Rainier days tend to result in noticeably higher radon levels. This is because rainy days are often coupled with lower barometric pressure.

Does the radon fan have to run continuously?

Yes. If you turn a radon fan off, the radon levels will return to the pre-mitigation levels within a few hours.  In addition, ground moisture will begin to enter the bearings and motor, causing a premature failure of the fan.

How can I be exposed to radon?

As radon travels through the soil, it can easily move through small spaces in a foundation and enter a building. This includes, but is not limited to, floor drains, sump pits, crawl spaces, foundation cracks and gaps around pipes and wires. The foundation makes no difference – radon has been measured in buildings with varying foundation styles. Since radon enters a building through the ground, lower levels such as basements, tend to have higher measured levels.

How do I know if my radon system is working?

You can tell if your system is working by looking at the u-tube.  Each system is installed with a u-tube monitor installed on the system piping.  One side of the u-tube has a vinyl tube plugged into the radon pipe.  The suction created by the radon fan draws the oil up the side of the tube connected to the radon pipe.  The difference in height between the two oil levels indicates the actual suction in the pipe induced by the fan in units of inches of water column.  If the two oil columns are level, the fan is off or not working and needs to be turned on or serviced.

How does a radon mitigation system work?

The most common radon system is a sub-slab depressurization system.  A fan, located in an attic or outside the building, is used to draw air out from under a basement, crawl space or slab on grade concrete slab.  If done properly, the entire area directly below the slab becomes negative in pressure as compared to the air above the slab.  This causes the normal airflow out of the soil to reverse and flow into the soil, which effectively stops all infiltration of radon laden soil gas.  The sub-slab depressurization system needs to create this sub-slab negative pressure under all slabs that are contributing a significant amount of radon into the building.

How does radon get in water?

Radon get in water when the ground produces radon, it can dissolve and accumulate in water from underground sources (called ground water), such as wells. When water that contains radon is run for showering, washing dishes, cooking, and other uses, radon gas escapes from the water and goes into the air. Some radon also stays in the water.

How does radon get into a building?

Great question. Most indoor radon comes into the building from the soil or rock beneath it. Radon and other gases rise through the soil and get trapped under the building. The trapped gases build up pressure. Air pressure inside homes is usually lower than the pressure in the soil. Therefore, the higher pressure under the building forces gases though floors and walls and into the building. Most of the gas moves through cracks and other openings. Once inside, the radon can become trapped and concentrated.

How is radon removed from water?

Radon can be removed from water by using one of two methods: aeration treatment or granular activated carbon (GAC) treatment. Aeration treatments involve bubbling air through the water. This helps to strip radon from the water. An exhaust fan is used to vent the radon outdoors. GAC treatment filters water through carbon. Radon attaches to the carbon and leaves the water free of radon. GAC filters tend to cost less than aeration devices. However, radioactivity collects on the filter and may cause a handling hazard and require special disposal methods for the filter.

How much will it cost to run the radon fan?

There are two energy costs.  The cost to operate the fan and the cost to replace indoor air that is sucked out of the house.  Radon mitigators that do not seal cracks and openings in the slab can raise the heating and cooling costs a larger amount than the cost to operate the fan.  Sealing not only reduces the loss of conditioned indoor air but also allows a a more efficient fan to be installed.  We use the most energy efficient fan sold that will effectively reduce the radon levels.  Two thirds of our mitigation systems use a 70-watt fan that costs about $80/year to operate.  One third of our systems use an 20-watt fan that costs about $25/year to operate.  This super-efficient 20-watt fan is very quiet and will save $600 or more in electrical cost over ten years. 

How often is indoor radon a problem?

Indoor radon can occur more often than one might think. Nearly one out of every 15 homes have a radon level the Environmental Protection Agency (EPA) considers to be elevated 4 pCi/L or greater. The U.S. average radon-in-air level in single family homes is 1.3 pCi/L. Because most people spend as much as 90% of their time indoors, indoor exposure to radon is an important concern.

How often should I test my home?

A radon test should be done when buying a home, after doing major renovations, every two years if there is a mitigation system installed or every five (5) years otherwise.

I don't live in an area with high radon, so am I safe?

Not necessarily. Even homes in areas considered at low risk for radon can have high radon levels. About 15 percent of homes in the U.S. have radon levels above the 4.0 pCi/L, the level at which the Environmental Protection Agency (EPA) recommends fixing your home. Although no absolutely safe level of radon has been determined. The World Health Organization’s (WHO) recommended level of 2.7 pCi/L, you will be helping to protect yourself and your family. The only way to know whether to fix your home is to test it for radon.

I have a new home with no cracks or other openings, so why should I test for radon?

Great question! As a gas, radon can seep through tiny cracks that you might not even see. It can get into finished or unfinished basements, and into new homes as well as old. You won’t know if it’s in your home unless you do a radon test.

I'm buying a house. Should I have it tested for radon?

Yes, you should have it tested. The Environmental Protection Agency (EPA) recommends that all houses, regardless of what radon zone the house is located in, be tested for radon during point of sale. The most common procedure for radon testing during real estate transactions is for the potential buyer to request the radon test as part of the overall home inspection. 

I'm selling a house. Should I have it tested for radon?

Yes, you should have it tested. The homeowner of a house can test their home prior to listing the home for sale. If the homeowner does perform a radon test, most if not all states will require that the test result be disclosed on the whole house disclosure form you will fill out with your realtor. If the initial test by the homeowner comes back less than 4 pCi/L, potential buyers may still request an additional radon test as part of their home inspection. If an initial radon test by the homeowner is 4 pCi/L or greater, the issue will need to be addressed in the real estate transaction. A buyer may want to have a confirmatory test conducted. With an average radon level of 4 pCi/L or greater, it is recommended that a radon mitigation system be installed prior to placing the house on the market, to bring the radon level to less than 4 pCi/L.

Is there really any proof that radon causes lung cancer?

Yes, there is proof. As with most illnesses, cause and effect cannot be 100% proved. Epidemiological studies have compelling evidence that radon is the number one cause of lung cancer in nonsmokers and that smokers who are exposed to high radon levels are 10 times more likely to get lung cancer.

The builder says my new home is radon-resistant, so I can't have radon, right?

Not necessarily. Even if you have purchased a home with Radon Resistant New Construction (RRNC), unless you, the builder or a home inspector tested your new home for radon, that’s not necessarily so. Although the name Radon Resistant New Construction implies that the home resists radon, it simply is the installation of radon system pipes without a radon mitigation fan. Without the fan, the home is “radon system ready,” but not resistant to radon entry.

What are factors can affect radon levels?

Several factors can influence your radon test results.

Time of year - Radon levels usually are highest during the heating season. If you are performing a long-term test, choose a time period that will span heating and non-heating seasons.

Test location - The Environmental Protection Agency (EPA) recommends testing for radon in the lowest livable level of your home, where radon levels usually are highest in the home.

Weather patterns - Do not conduct a short-term test during conditions that can influence the test results, such as stormy weather or very high winds.

Test interference - Do not move the test device or open doors and windows during the test, as these actions can result in understated radon levels.

Follow directions - Leave the test in place for the required time period, fill out all required information and mail the device to the laboratory immediately after completing the test.

What are the benefits of radon mitigation?

There are many benefits. The primary benefit is reducing the risk of developing lung cancer.  Standard radon reduction systems are usually effective within 24 hours and maintain low levels as long as the fan is operating.  Another potential benefit of these systems is reduced infiltration of moist soil air with the radon, which may reduce the humidity level in the basement of the home.  

What can be done to reduce radon in a home?

Your house type 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 have more than one foundation design feature. For instance, it is common to have a basement under part of the house and to have a slab-on-grade or crawlspace under the rest of the house. In these situations, a combination of radon reduction techniques may be needed to reduce radon levels to below 4 pCi/L.

What factors should I look at in deciding whether to mitigate or not?

Here are a few factors to consider. Cigarette smokers should keep their exposure to radon as low as possible. Smokers have a higher risk from radon than non-smokers. If the house was tested in an infrequently used basement, it may have measured a radon level that is higher than the actual level you are exposed to, spending most of your time upstairs. People with young children should be more concerned with the possible consequences of radon exposure 20 years from now than someone in their late sixties or seventies. Families with a hereditary predisposition to cancer should be more concerned about radon exposure than families who don't have any history of cancer.

What health effects are associated with radon?

When radon and radon decay products are inhaled, they can cause damage to the cells and tissues of the lungs, which can lead to lung cancer over the course of a lifetime. Not everyone who is exposed to radon will get lung cancer. The time between exposure and cancer diagnosis may be many years.

The U.S. Surgeon General has warned that radon gas is the second leading cause of lung cancer in the United States (second only to smoking), and first among non-smokers. Individuals who smoke and are exposed to high levels of radon are especially vulnerable.

What is a radon mitigation system?

A radon mitigation system is any system or steps designed to reduce radon concentrations in the indoor air of a building. The basic system consists of PVC pipes and a Radon fan, which will pull the radon gas out of the soil from beneath the home and out in the air where it will be diluted.

What is a safe Radon Level?

There really is no safe level of radon exposure. Radon gas is measured in picoCuries per liter (pCi/L). The current airborne radon level at which the Environmental Protection Agency (EPA) recommends action is 4.0 pCi/L. Further, the Environmental Protection Agency (EPA) says to consider action if the level is 2 to 4 pCi/L and suggests that every home and workplace be tested for radon gas in the air.

What is Radon?

Great question. Radon is a radioactive gas, naturally found in soil and rock. It is colorless, odorless, tasteless, and chemically inert. Unless you test for it, there is no way of telling how much is present.

Why are my two radon tests results different?

Very good question. Some difference between radon tests is expected because radon levels fluctuate due to weather and house conditions.  It is not uncommon for radon levels to be twice as high or one-half of previous measurements.  Upstairs measurements, in particular, can be significantly different in heating versus cooling seasons.  Basement measurements tend to be more consistent in different seasons.  A basement measurement that is ten times higher or one-tenth of a previous measurement would be unusual.

Why is 4 pCi/L the recommended action level for Radon?

Environmental Protection Agency (EPA) recommended this mitigation action level in 1986 for several reasons. First, at lower levels (2 pCi/L) measurement devices’ false negative errors increase threefold, and false positive errors increase twofold. Secondly, mitigation research indicates that elevated levels can be reduced to 4 pCi/L or less 95% of the time. Research shows that 2 pCi/L can be achieved 70% of the time.

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