The level of 4.0 picocuries per liter of air (pCi/L) or more of home indoor air is considered dangerous by the United States Environmental Protection Agency (EPA) and needs lowering, but it is only a recommendation and not a federally enforced requirement. The level at which action is recommended is set both higher and lower by other countries and health organizations around the world. The World Health Organization (WHO), for example, has established 2.7 pCi/L as their maximum safe radon level.

    When considering all the different standards set for the radon of indoor air, it’s important to know several additional facts:

1) Radon is in the air everywhere and is impossible to totally eliminate. Radon can only be reduced.

2) Living in a home with high radon is not a lung cancer death sentence. It simply increases your likelihood of getting lung cancer by a few percent compared to a home with a lower radon level. Anything that increases in the probability of lung cancer is, however, still worth fixing.

3) The combination of cigarette smoking and high indoor radon greatly increases the probability of lung cancer.

4) Unlike cigarette smoking, which produces a clearly identifiable type of damage in the lungs, a doctor cannot tell you that your lung cancer was caused by radon.

5) The standard of 4.0 pCi/L was established based on the elevated lung cancer death rate of uranium miners years ago, many of whom also smoked. There is an extremely high level of radon in the air in uranium mines because radon produced by the radioactive decay of uranium. The standard was based on a “linear no-threshold” model. This can be compared to evaluating a dangerous highway curve with a 50 mph speed limit and 5 deaths per year, and determining that to cut it to one death per year would require reducing the speed limit by 4/5 to 10 mph.

6) While there is some disagreement about what radon level is safe, scientists agree that exposure to high levels of radon over a long period of time definitely increases your risk of lung cancer.

7) If you happen to read a tear-jerker story about how “my father died of lung cancer and, if we had only known the house had radon at twice the EPA’s acceptable level and fixed it, we could have saved his life,” you are on a website that wants to sell you a radon mitigation system. While exposure to a level of radon above the EPA limit increases your risk of getting lung cancer, we have inspected homes with extremely high radon that the residents have lived in for many years without a lung cancer diagnosis. But they were lucky.

8) Although you may choose to live in a house that might have an elevated radon level, but you do not decide to test to for it, and if a potential homebuyer does a radon test during the inspection period when you sell the home and finds elevated radon, you have a problem. It must either be fixed or disclosed to the next homebuyers as a defect that negatively affects the value of your home.

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Here’s links to a collection of our blog posts about “RADON":

• Can a radon test result be wrong?

• Is a radon mitigation fan required to be on a dedicated circuit breaker/fuse in the electric panel?

• What happens to a radon test result if the windows were opened, the test device moved, or there was any other evidence of tampering during the test? 

• Where do I find the Florida laws regarding radon?

• Can I test vacant land for radon before building a house? 

• Is radon mitigation possible for a condominium?

• Do radon mitigation systems require maintenance?

• What is the average life expectancy of a radon mitigation system?  

• Do older houses have higher radon levels than new houses? 

• Can the seller tamper with a homebuyer's radon test to change the results?

• How long does it take to get the results of a radon test? 

• Will opening the windows reduce the radon level in a house?

• How was it determined that between 15,000 and 22,000 lung cancer deaths each year are caused by radon?

• Can a homebuyer do their own radon test for a real estate transaction with a self-test kit?

• What is the danger of radon in well water?

• What are the symptoms of radon poisoning? 

• Does Florida have radon?

• Where does radon come from? 

• For how many years does an old radon test result remain valid?

• Should homeowners get a pre-listing radon test before selling their home?

• What are a homebuyer's options when the radon test comes back high (4.0 pico-curies/liter or more)? 

• Do granite countertops emit radon?

• How can I tell if a house has a radon mitigation system? 

• Can a mobile/manufactured home have a high radon problem?

• Do I need to test for radon when buying a condominium? 

• What does a radon mitigation contractor do to lower the radon level in a home?

• How can not testing for radon be an expensive mistake for homebuyers? 

• Will the radon test come back sky-high in a house that has been empty and closed-up for months? 

• What is radon? Should I be concerned about it?

• Should I buy a house with a high radon level? 

• What is the average radon level of indoor and outdoor air in America?

• What is the operating cost of a radon mitigation system? 

• Should I buy a house with a radon mitigation system?

• Does the buyer or seller of a home pay for radon mitigation when the radon test comes back high? 

• What is the probability of having high radon in a Florida house?

• How quickly do I need to reduce a high radon level in my house? 

• Does a home inspector check for radon?

• What are the problems with underground return air ducts? 

• What is the probability of having high radon in a Florida house?

• How do I know if a radon mitigation system is working? 

• Can I sell a house with a high radon level?

• Does heavy rain change radon levels? 

• Does barometric pressure change radon levels?

• Do high winds affect radon levels? 

• What factors can change radon test levels up or down?

    Visit our RADON page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.