Frequently Asked Questions: Radon


What is an acceptable level of radon?
The US EPA recommends that you take action if your radon level is above 4.0 pCi/l (pico Curies per Liter).

What risk does high levels of radon pose?
High levels of radon have been shown to increase the risk of developing lung cancer. Radon-induced lung cancer is the second highest cause of lung cancer after cigarette smoking.

Are there any additional risks to radon exposure other than lung cancer?
No. There are no known risks to radon exposure other than lung cancer.

Is there a 'threshold' below which there is little or no risk to developing radon induced lung cancer?
No. Scientists believe that radon risk is strictly 'linear' related to exposure. This means that if you reduce levels from 4.0 pCi/l to 2.0 pCi/l you are now half as likely to develop radon induced lung cancer than before reduction.

What is the lowest level of radon that could be achieved?
The natural level, outside, of radon is normally considered to be 0.4 pCi/l, or about one-tenth the indoor 'action' level.

How does radon cause lung cancer?
A single radon atom can give off an alpha particle that, within itself, can damage a DNA cell in just the right way to cause cancerous growth. Thus, in theory, even a single radon atom can cause lung cancer.

How many people die of radon-induced lung cancer?
It is estimated that 21,000 people die of radon-induced lung cancer each year in the United States.

How do radon deaths compare to other publicized causes of death?
Radon deaths are significantly higher than vehicular deaths caused by drunk driving, 50% higher and about 8 times higher than deaths due to the asbestos disease Mesothelioma.

If so many people die each year, why aren't radon dangers more publicized?
Some experts believe that the deaths caused by radon aren't as publicized as deaths caused by other causes because radon is naturally occurring, and there is no 'villain' or anyone to sue as there is in drunk driving, asbestos, and smoking-caused fatalities, for example.