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What radon level is dangerous?
Tuesday, February 25, 2020
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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