Radon is a radioactive element that is part of the radioactive decay chain of naturally-occurring uranium in soil. Radon is invisible, odorless and cannot be tasted. Unlike carbon monoxide and many other home pollutants, radon's adverse health effect, lung cancer, is usually not produced immediately. Thus you may be exposed to radon for many years without ever suspecting its presence in your home.
The USEPA action level for radon is 4.0 picocuries per liter of air (pCi/L). The risk of developing lung cancer at 4.0 pCi/L is estimated at about 2 lung cancer deaths per 1000 persons. That is why USEPA and IDNS recommend reducing your radon level if the concentration is 4.0 pCi/L or more.
Radon reduction techniques are used to stop radon entry and reduce indoor radon concentrations. IDNS recommends hiring a licensed mitigator to reduce your indoor radon concentrations, as you would hire a licensed plumber, HVAC or other specialist. Experienced do-it-yourselfers are advised to exercise radiation protection precautions when installing a mitigation system, such a thoroughly ventilating the work area.
Trained radon professionals using specialized equipment can discover where radon is entering and advise homeowners on the best way to reduce radon concentrations. While mitigation can be performed in stages, with testing after each stage to evaluate the degree of success attained, the most common technique used by radon reduction firms is called "subslab depressurization" (SSD) and does not require major renovations. Post-mitigation testing must be performed in accordance with pre-mitigation testing protocols.
An SSD used without a fan is called a "passive SSD" and relies on air currents instead of a fan to draw radon up from below the house. Passive SSD is generally not as effective in reducing high radon levels as active SSD.
The cost of an active SSD is between $800 to $2,500 for installation, and the energy cost for running the fan will average between $75-$175 per year.
For individuals and companies building new homes, IDNS recommends installation of a "passive SSD" during construction; homeowner testing after taking residence; and mitigation, as indicated by the test results. The Council of American Building Officials (CABO) has included radon control methods in their One and Two Family Dwelling Code since 1995. Illinois towns concerned about residential radon concentrations, including Normal and East Moline, have adopted the CABO code, making passive SSD installation mandatory for new single-family dwellings in their areas.
For further information about radon, radon measurement and mitigation, or for a list of licensed radon professionals in, or near, your area, call IDNS at 1-800-325-1245.