1. About Radon

Radon is a radioactive element that is part of the radioactive decay chain of naturally occurring uranium in soil, and it is the leading cause of lung cancer among non-smokers in the United States.

You can’t see it, smell it or taste it. Unlike carbon monoxide and many other home pollutants, radon's adverse health effect, lung cancer, usually doesn’t happen immediately. It occurs over the time, with frequent exposure to high levels of radon gas.

The EPA has determined that concentrations of more 4.0 picocuries per liter of air (pCi/L) represent a serious health risk. The risk of developing lung cancer at 4.0 pCi/L is estimated at about 7 lung cancer deaths per 1000 persons.

Lung cancer in humans arising from radon exposure is recognized by the following health and environmental organizations:

  • American Medical Association
  • U.S. Surgeon General
  • U.S. Department of Health and Human Services
  • U.S. Public Health Service
  • U.S. Environmental Protection Agency
  • Center for Disease Control
  • National Academy of Science
  • National Cancer Institute
  • World Health Organization

2. How Does Radon Enter My Home?

Radon enters a building when released from the soil. When Radon is released into the open air, it doesn't pose a threat because it is such a small amount compared to the overall environment. However, when radon enters the interior of a building, through cracks in the foundation or other similar infiltration points, the concentration of this deadly gas can reach dangerous levels.


  • Cracks in solid floors
  • Construction joints
  • Cracks in walls
  • Gaps in suspended floors
  • Gaps around service pipes
  • Cavities inside walls
  • The water supply

3. Detection of Radon

Are you careful to manage smoking and secondary smoke in your home? According to the EPA and other health organizations, Radon is another hazard you should be concerned about.

Smoking, radon, and secondhand smoke are the leading causes of lung cancer. Although lung cancer can be treated, the survival rate is one of the lowest for those with cancer. From the time of diagnosis, between 11 and 15 percent of those afflicted will live beyond five years, depending upon demographic factors. In many cases lung cancer can be prevented; this is especially true for radon.

Radon is the number one cause of lung cancer among non-smokers, according to EPA estimates. Overall, radon is the second leading cause of lung cancer. Radon is responsible for about 21,000 lung cancer deaths every year. About 2,900 of these deaths occur among people who have never smoked. On January 13, 2005, Dr. Richard H. Carmona, the U.S. Surgeon General, issued a national health advisory on radon.

Studies Find Direct Evidence Linking Radon in Homes to Lung Cancer - Two studies show definitive evidence of an association between residential radon exposure and lung cancer. Two studies, a North American study and a European study, both combined data from several previous residential studies. These two studies go a step beyond earlier findings. They confirm the radon health risks predicted by occupational studies of underground miners who breathed radon for a period of years.

Early in the debate about radon-related risks, some researchers questioned whether occupational studies could be used to calculate risks from exposure to radon in the home environment. “These findings effectively end any doubts about the risks to Americans of having radon in their homes,” said Tom Kelly, Director of EPA’s Indoor Environments Division. “We know that radon is a carcinogen. This research confirms that breathing low levels of radon can lead to lung cancer.”

The World Health Organization (WHO) says radon causes up to 15% of lung cancers worldwide. In an effort to reduce the rate of lung cancer around the world, the World Health Organization (WHO) launched an international radon project to help countries increase awareness, collect data and encourage action to reduce radon-related risks. The U.S. EPA is one of several government agencies and countries supporting this initiative and is encouraged by WHO’s attention to this important public health issue. "Radon poses an easily reducible health risk to populations all over the world, but has not up to now received widespread attention," said Dr. Michael Repacholi, coordinator of WHO’s Radiation and Environmental Health Unit.

4. Radon is a Radioactive Gas

For centuries, people have been exposed to radon gas without knowing it and without linking it to radon or reporting any adverse health problems caused by it. Radon gas in our environment comes from the natural breakdown of uranium in soil, rocks, and water. Outdoors it present little or no health risk as it diffuses into the air. It's indoor, trapped concentrations of radon gas that present the potential dangers. The USEPA action level for indoor radon levels is 4.0 pico curies per liter of air (pCi/L).

Radon is a radioactive element that is part of the radioactive decay chain of naturally occurring uranium in soil. You can’t see radon. You can’t smell radon and you can’t taste radon. 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 problem with radon comes from its radioactive decay products, called daughters, which emit high levels of alpha radiation and are not chemically inert. This allows them to attach themselves to tobacco smoke and dust particles in the air. When inhaled, these smoke and dust particles can lodge in the respiratory system where they subject the lung tissue to radiation. Radon daughters have relatively short half-lives, so that after being deposited in the lung, they will successively go through their radioactive decay in an hour or less. Currently, there are no reported instances of radon-related problems traced to a short-term exposure period.

5. You Should Test for Radon

While scientists can estimate the approximate lung cancer deaths per 1000 people, no single individual's risk can be estimated. Testing is relatively inexpensive, easy and is the only way to know whether you are at risk.

Testing for radon is normally done using self-testing kits or electronic radon monitors. Inexpensive passive test kits are available for use in residences. Approved test kits must have passed the EPA’s testing program or be state-certified. Some of these tests measure radon levels over two to three days; others measure it over one to three months. Professional testers may use a method of active sampling that involves the use of a membrane filter and a battery-operated air pump to collect particulate matter to which the radon daughters are attached. After a predetermined time has elapsed, an alpha-particle detector is used to measure the radon level in pico curies per liter (pCi/L). This value is then converted and reported as working levels.

6. Radon Mitigation

Radon reduction techniques are used to stop radon entry and reduce indoor radon concentrations. IEMA recommends hiring a licensed Mitigation Professional to reduce your indoor radon concentrations, as you would hire a licensed plumber, HVAC or other specialist.
As trained mitigators, we utilize specialized equipment to discover where radon is entering the building and advice homeowners on the best ways to reduce radon concentration based on their unique situation.

The most effective measures for reducing radon, without costly renovations, are ones that limit soil gas entry into the building. In general, dangerous vapors are extracted from the soil and rock below the structure then exhausted, safely away from the building, minimizing internal air intrusion.

One common and very reliable method uses Active Sub-slab Depressurization (SSD). This method uses a radon mitigation exhaust system to reduce the pressure below the floor slab so that the air between the building substructure and the soil flows out of rather than into the building. Sub-Slab Depressurizations systems are customized for each property, to address specific mitigation requirements.

7. In the Basement

A sub-slab depressurization system consists of PVC piping installed through the basement slab floor with a fan connected to the piping. When the system is on, the fan applies a vacuum beneath the slab and the vapors in the soil beneath the building are suctioned into the pipe, and then exhausted. The primary suction provided is independent from the sump pit.

8. Exhaust

Radon is exhausted up through a PVC pipe, exiting above the highest eave of the structure. Discharging the exhaust above the highest eave ensures dilution of the exhaust to outdoor air and minimizes risk of radon entering the structure.

Additionally, exhaust outlets are installed as close to the roof ridge line as possible, 10 feet or more away from doors, windows or other openings in the building, and 10 feet or more from any openings in nearby structures.

9. System Monitor

In addition to the system functioning indicator, a simple U-tube manometer is mounted to the Sub-slab depressurization system vent pipe. The manometer is widely used to monitor the operation of the sub-slab depressurization system fan. When the liquid levels in the legs of the manometer are uneven, a pressure differential exists, indicating correct operation of the fan and system. Conversely, if the manometer liquid levels are even, the fan or system is not operating properly and needs repair.

Sump pump covers are also installed with observation ports for performance monitoring.

10. In a Crawl Space

A Sub-Membrane Depressurization (SMD) may be required for crawl spaces and other areas where the slab is in direct contact with the rock and soil. With the SMD method, a plastic sheet (Polyethylene or similar) is permanently installed over exposed rock and soil. A fan is then installed to create suction under the plastic sheeting, drawing the vapors out from the soil into a PVC pipe, then safely exhausted away from the home, minimizing vapors from entering ambient indoor air, similar to the SSD method.

11. Continuous Operation Required

Both Sub-Slab & Sub-Membrane Depressurization systems must run continuously to be effective. These systems use little electricity, are relatively quiet, and require very little maintenance It is recommended that a professional inspect the system periodically to ensure proper performance.

12. Exhaust Elements

Exhaust fans and piping are typically mounted on the exterior "equipment" side, of the building, towards the back, in the most inconspicuous space. Optional fan housing units are available for aesthetic purposes.

Exhaust piping is standard 3 inch PVC. Both the pipe and the fan housing may be painted to match the exterior or the home siding or trim. (Painting not included).

13. Sealing

Sealing increases the overall effectiveness and cost efficiency of a mitigation system. Sealing cracks and gaps to limits airflow into the and out of the building enhances radon reduction efforts, by further blocking radon entry points and reducing the loss of costly conditioned air. IEMA does not recommend the use of sealing alone to reduce radon concentrations.

14. Building Codes & Standards

All systems installed by Midwest Radon Services, LLC, meet or exceed IEMA and EPA standards as well as Illinois building code requirements.