Health Information

        The primary health hazard of radon comes from inhalation of the gas and its highly radioactive heavy metallic decay elements (Polonium, Lead, Bismuth) which collect on dust in the air. These elements can stick to the cells lining the passageways into the lungs. There is significant evidence for the carcinogenicity of radon and its isotopes. 

    Outdoor radon levels in the United States range from 0.02 pCi/L to 0.75 pCi/L. The Environmental Protection Agency states that the target level of 0.4 pCi/L of radon in a household set by Congress is equivalent to getting a chest x-ray or smoking 10 cigarettes a day. 

For average indoor levels of radon in the U.S., see map below. 

click here to view the effect of atmospheric air movements on radon levels in buildings. 

click here for information on testing your home.

For pictures of radon detection devices and related information, go here.

EPA's Map of Radon Zones

The Effects of Atmospheric Air Movements on Radon Ingress into Buildings

Animation sequence

Radon in soil gas movement

"As wind speeds increase, the airflow over the building creates pressure differences which in turn encourage soil gas movement into the property. A venturi effect is set up which lowers the pressure over the lee side of the roof drawing air out of the building. In addition a high pressure area is set up on the windward side of the building and in the ground. Thus the pressure difference inside and out is increased as the wind velocity increases. The pressurised air suffuses though the ground and is drawn into the building, any radon present in the soil is drawn along with this air movement and can increase radon concentrations in the building." (from

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