Radon in your home significantly increases your family’s risk for developing lung cancer. Reducing this risk is easy:

  1. Test for radon in your home. Testing is easy and inexpensive. 
  2. Fix high radon levels. When fixing is needed cost is typically comparable to other regular home maintenance.

Radon is the single largest source of radiation for almost everyone in Washington. Radon is the leading cause of lung cancer among nonsmokers, according to the U.S. Environmental Protection Agency, and the second leading cause behind smoking. It is easy to decrease your risk by conducting an inexpensive in-home radon test and, if necessary, fixing your home.

What is radon?

Radon is a naturally occurring radioactive gas that is invisible, odorless, and tasteless. It comes from the radioactive decay of radium, an element found in most rocks and soils. Radon can enter a building from the ground underneath it and concentrate to tens, or even hundreds, of times the level in outdoor air.

How does radon get in my home?

Radon gas is invisible, odorless, and tasteless. It is created by the radioactive decay of radium, a naturally found element in most rocks and soils. Radon gas emitted from the ground under a building’s foundation can enter through small gaps and cracks in the foundation and floor and concentrate to tens, or even hundreds of times the level found naturally in outdoor air.

How can radon affect me?

Radon can cause lung cancer. Longer exposure and higher levels elevate risk further. As radon radioactively decaysthe particles and photons released can hit, damage, or even destroy cells. Lung cancer can form when a lung cell is damaged and the cell does not repair itself correctly. The more radon you are exposed to, the greater the opportunity for cell damage. Although smoking is the leading cause of lung cancer, the risk is much higher for an individual who smokes and is exposed to radon. Learn about tobacco-related disease.

How can I tell if I have radon in my house?

The only way to know if you have elevated levels of radon is to test. Easy-to-use, inexpensive test kits are available online, and from many home improvement and hardware stores. A limited number of testing kits are available for free from the Department of Health, and can be requested in English, Russian, Spanish, and Vietnamese. You can also hire a professional radon tester. A professional tester is often hired when radon detection is part of a real estate transaction. Find lists of professionals from the National Radon Proficiency Program and the National Radon Safety Board.

What can I do if I have elevated levels?

Test, Fix, Re-Test

If you have tested your home and found elevated radon levels there are some simple things you may be able to do yourself to help reduce radon levels. Whether you attempt fixes yourself or hire someone else, be sure to conduct a follow-up test when the work is done to ensure your efforts have made the needed impact and reduced radon levels. 

Three simple things help reduce radon levels in your home: 1. Make it harder for radon to get in. Caulk and seal cracks in your basement, foundation, and subfloor. 2. Install a good vapor barrier in your crawl space. The goal is to have a gas-tight barrier between the inside of your home and the ground underneath. 3. Make it easier for radon to go somewhere other than in to your house. Ensure foundation vent-blocking is clear and offers unobstructed venting for your home’s crawl space. Increase air exchange with the outside. A home’s radon levels will often test higher in winter when the home is being heated, and in summer when the home is being air conditioned. When temperatures are more mild windows are often open and radon gas cannot concentrate in the home like it can when the home is sealed. 

Elevated home radon levels can quickly be reduced by a radon mitigation system installed by a certified radon mitigation specialist. Like most any home feature a radon mitigation system can be installed much easier and at much less expense during a home’s construction. Radon-Resistant New Construction techniques can be used while a new house is being built to help ensure radon is kept outside of your home.

How do I know if I have been exposed to radon?

Medical tests are not available to determine whether you have been exposed to radon. If you are concerned, talk with your doctor.

Where can I find a radon mitigation professional?

If your home has elevated levels of radon, you can hire a certified professional to reduce the amount of radon can enter your home or increase ventilation to remove radon from your home. Find a radon mitigation professional through one of these national certifying organizations:

National Radon Proficiency Program

National Radon Safety Board

My child's school tested for radon - What should I know?

The risk of developing lung cancer from exposure to radon increases from long-term exposure to radon over a number a years. While we recommend that schools test and reduce exposure to elevated levels of radon, it is even more important to test and reduce exposure to radon where your child will spend the most time over the years, which is typically within the home.

Children's Environmental Health Network Eco-Healthy Child Care (PDF) (Spanish PDF)

Mapping Radon Exposure in Washington

Radon Maps and Data

Maps and data showing radon risk in our state can be viewed on the Washington Tracking Network.

Visit an environmental health tool to view radon test data for communities and a radon risk map. The tool shows radon and lead risk as topics; we are working to expand topics. You can read information about radon risk and how to get your home tested in the notes section of the online tool.

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