Radon Gas in Homes: 15 Things (2024) You Ought to Know

While it can be exciting to purchase a home, you don’t want to overlook anything that could cost you down the line – and one of these things is radon gas in homes.

Here’s what you should know about this radioactive gas.

1. What is radon gas?

Radon is a colorless, odorless, radioactive gas that you can’t see, smell, or taste.

As a result, you must detect it with special equipment.

Radon gas in homes can increase the risk of lung cancer, particularly in smokers.

In fact, exposure to radon gas is the second leading cause of lung cancer (after smoking) each year.

Annually, it’s estimated to cause around 21,000 lung cancer deaths in the U.S.

2. Where can radon gas be found?

You can find radon gas anywhere.

However, certain parts of the country are more likely to have higher exposure levels than others.

Thus, if you’re looking for a house or land in one of these areas, you’ll want to get it checked before buying.

The United States Environmental Protection Agency (EPA) estimated in 2009 that 6 percent of homes (approximately 6 million US houses) have concentrations of radon above 4 picocuries per liter (pCi/L).

Here are the five states most common for radon:

bulletAlaska: 10.7 pCi/L

bulletSouth Dakota: 9.6 pCi/L

bulletPennsylvania: 8.6 pCi/L

bulletOhio: 7.8 pCi/L

bulletWashington: 7.5 pCi/L

3. How does radon gas get into homes?

You may be wondering about radon gas in homes…how does it get there?

Radon naturally forms from rocks and soil.

The levels may be very low in the air outside, but they’ll be higher in buildings because it’s contained.

4. What is a “radon-affected” area?

Many states and counties have maps showing areas with high levels of radon and you can contact your state radon office for a copy.

But what if you find your home is in an area with high levels of radon?

Should you not buy a house in a “radon-affected” area?

Thinking there’s radon gas in the homes you’re looking at can be scary.

Because the level of radon is affected by the underlying geology in the area as well as factors like how the building is constructed and the habits of the occupants (i.e., ventilation, heating, etc.), the map doesn’t necessarily need to dictate your decision.

The map can open the conversation.

It can get you thinking about radon gas in the area.

But it doesn’t need to be why you panic or pull out of a transaction.

If you see your potential home on a radon-affected area map, then you should reach out to a professional to conduct a radon risk report.

If it comes back with high readings, then you should dig deeper.

5. Should you worry about radon gas in homes?

Keep in mind there’s no such thing as a “safe” radon level.

This is because radon and radiation exposure affects people differently.

We also know that lowering your exposure to radon helps to lower the risk of developing lung cancer which can occur as a result of prolonged exposure to radon.

The EPA recommends treating homes with radon levels as low as 2 pCi/L.

That is a radon level that’s half the amount considered outright dangerous.

The average radon gas concentration in a home is estimated at 1.3 pCi/L.

The concentration outdoors is 0.4 pCi/L.

6. Does a quality of a lab radon test make a big difference?

Many people wonder if they need to spend money on a lab professional to get accurate radon results.

Can they perform the test themselves to see if there’s an issue?

Test kits are a great resource when it comes to radon testing.

However, they can be inaccurate and inconsistent.

If you want to make sure that you get an accurate result right away, reach out to a qualified, professional radon contractor.

The results they give you will always be the most accurate.

7. What is radon gas testing?

Radon testing is the only way to know if your home has a high radon level.

Most of these tests can be performed without professional assistance.

However, there are several different types of tests that are designed based on your situation and what you need.

bulletShort-term radon test

This test is useful if you need to see if additional testing is required.

Radon levels must be measured for a minimum of two days.

After that, the test is mailed to a lab for the results.

bulletLong-term radon test

This test takes much longer.

It measures the radon levels in a building for a minimum of 90 days; although, it could be up to 1 year.

The long-term test is a more accurate indicator of the average radon level in a building than the short-term test.

bulletContinuous radon test

Unlike passive radon test kits (which don’t require power), a continuous radon monitor is an electrically-powered device that tests your home for radon at set intervals.

Thus, you don’t need to send samples to a lab and wait for the results.

Continuous radon monitors can be used for both short and long-term testing.

People also use these devices if they want daily readings or if they want to keep a running average of the amount of radon that’s in their homes.

8. What is radon remediation?

Radon remediation, also known as radon mitigation, is any process that’s used to reduce the concentration of radon gas in homes or other breathing zones of occupied buildings.

Here are the steps you should follow.

bulletStep 1: Test for radon gas

You can’t skip right to the remediation process.

You must test to see if radon gas exists in your home, and if it does, how bad the issue is.

bulletStep 2: Decide which type of remediation system you want to use

Once you have tested for radon, there are three different types of radon remediation methods you can use: sub-slab depressurization, sub-membrane ventilation, and block wall suction.

Each system will help you remove radon from your home through a different method.

  1. Sub-slab depressurization: This system works by running a pipe from the soil beneath the house through the concrete basement slab and up the side of the home. The pipe is connected to a fan that creates a vacuum and sucks up the radon gas from beneath the foundation. It then vents the radon to the outside of the home.
  2. Sub-membrane ventilation (or depressurization): This system is similar to sub-slab depressurization except that a membrane is placed over earth or gravel. Sub-membrane systems are typically used for homes that have a basement or crawlspace with earth floors
  3. Block wall suction: This system lowers the air pressure within a block wall. Combined with a fan and ductwork to create suction on a concrete wall’s hollow internal cavities, this helps to remove radon gas from the soil. If your home has hollow foundation walls, this system could be a good fit.

bulletStep 3: Retest for radon gas

After you’ve completed remediation, you’ll need to rest for radon gas periodically to make sure you’ve found a solution and you’re continuing to protect your health.

9. How can you reduce radon levels in your home?

There are several proven methods that you can use to reduce radon in your home.

We’ll list the most common ones below.

bulletInstall a radon reduction system

This system (see section 8) pulls radon from beneath the house and vents it to the outside.

To find the right system, you’ll need to evaluate the type of home you have as well as its features.

For example, having a basement will change how it’s installed.

Additionally, sealing foundation cracks and other openings make a soil depressurization or ventilation system more efficient and cost-effective.

bulletOpen windows and use fans in your house.

This will increase the airflow and help to reduce radon gas temporarily.

Note that this method is only a temporary solution.

You should not rely on this as your primary strategy.

bulletSeal all cracks in your floors and walls with appropriate materials (plaster, caulk, etc.).

After you install any system to help reduce radon gas, make sure you test your home again to ensure it’s working.

You’ll want to retest your home every two years to ensure the radon levels remain low.

Another key time to retest is after you’ve done any home remodeling.

10. What is the difference between passive and active remediation?

Each type of system uses either passive or active remediation to see results.

For example, fans and ducts use active remediation to pull radon from the air and vent the gas outdoors.

On the other hand, passive methods lack the fans of an active system.

Rather, they utilize pressure differentials and natural airflow to vent the radon gas from the area.

If you need a highly effective method of removing and venting radon gas from your house, then you should go with an active system.

11. How do I know which type of remediation system to get for my home?

The best type of radon remediation system will be the one fit for your home’s construction.

The most-used type is the sub-depressurization system.

However, that doesn’t mean you should select this type without double-checking with a professional.

The other systems exist for a reason, and you may find that one is more productive for you (i.e. if you have an unfinished basement with an earth floor that could benefit from a sub-membrane ventilation system).

12. How much does it cost to mitigate the effects of radon gas in homes?

The cost of radon remediation varies depending on the type of system you select as well as other factors related to your home construction.

Here’s what you should keep in mind when researching the cost of radon gas mitigation.

bulletHouse age



bulletType of foundation

bulletConstruction materials used

bulletLocal climate

bulletAesthetic preferences

13. Where in your house is radon gas most likely to be?

When homes have radon, they often have the highest levels in the basement or crawl space.

14. What are the symptoms of radon poisoning?

Here are some signs and symptoms that you may have radon poisoning.

bulletPersistent cough



bulletShortness of breath

bulletCoughing up blood

bulletChest pain

bulletFrequent infections like bronchitis and pneumonia

bulletLoss of appetite

It can take years before health problems appear because of radon.

Radon doesn’t impact you overnight, so it’s worth getting your house checked for radon today if you suspect there may be any issues.

15. Should I only buy a house with a radon mitigation system?

Radon is everywhere.

That’s a fact.

If you know the property has high radon concentrations, an existing radon mitigation system will save you the time and cost of having to go through testing and mitigation after buying.

However,  it doesn’t necessarily make or break a sale.

Buy a home with radon mitigation if you can — if it’s convenient.

But don’t feel the need to go out of your way to only look at homes that have them.

It’s easy enough to install one if it’s necessary.

Also, keep in mind that no mitigation system works forever.

You’ll still have to test for radon again down the road.

You’ll also need to seal crafts as your home’s foundation continues to settle.

Final Thoughts

Learning about radon gas in homes is critical when you’re interested in purchasing real estate.

As substances like uranium and thorium deteriorate, this odorless and tasteless gas seeps up to the surface and into buildings.

It’s a leading cause of cancer, and as a result, it’s worth investing in testing and mitigation efforts.

Use our tips above to avoid health issues in a house you otherwise love.

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Erika Gokce Capital

Disclaimer: we are not lawyers, accountants, or financial advisors and the information in this article is for informational purposes only. This article is based on our own research and experience and we do our best to keep it accurate and up-to-date, but it may contain errors. Please be sure to consult a legal or financial professional before making any investment decisions.


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