About Radon

Radon and Its Risks

Radon is a radioactive gas that forms when the Uranium in natural stone decays. The gas decays into radon progeny which are radioactive metal atoms that get caught in our respiratory tracts during inhalation. Radiation emitted from the radon progeny causes lung cancer by damaging the cells in our respiratory tracts and lungs. Radon causes an estimated 22,000 deaths a year and is present in every home.

Both the Environmental Protection Agency (EPA) and Health Canada have established guidelines to assist in determining radon risk. Yearly exposure levels of radon gas should not exceed 4.0 pCi/l in the US and 200 Bq/m3 in Canada. If levels are detected at or above these guidelines it is recommended that action be taken to reduce your exposure.

Measurement of Radon in Indoor Air

Radon gas is both odorless and invisible, meaning a test is the only way to detect the gas. The amount of radon in indoor air will vary depending on structural deficiencies, ventilation, and is influenced by the weather outside. Due to these factors, it is recommended that all dwellings, schools, and workplaces be tested for radon gas.

Consider Measuring Radon in the Indoor Air

  • Immediately if a radon test has never been performed before and every two years as environmental conditions change
  • After any renovation, as small cracks can arise in the foundation and renovations to a home can change air flow and ventilation
  • Every year, if you have previously taken action to reduce a high radon level

Using our Radtrak²®, a measurement should be for a duration of at least three months, ideally a full year, as the guidelines are based on year long exposures and the longer the period the more accurate the measurement. In some cases, measurements are conducted over a shorter measuring period in order to obtain an approximate value. Short-term measurements with our specially designed detector Rapidos®, require a period of at least 10 days. These tests can be used as preliminary tests for residences to get a quick evaluation and determine if remediation is needed immediately or in projects when a smaller sampling window is required.

US and Canada Action Levels for Radon in Indoor Air


The EPA has set a radon guideline of 4.0 pCi/l (picocurries per liter of air) for indoor measurements. This average is calculated by taking your homes total radon concentration and dividing it by the amount of days the radon detector was monitoring.


Health Canada set a radon guideline of 200 Bq/m3 (becquerels per meter cubed) for indoor measurements. This average is calculated by taking your homes total radon concentration and dividing it by the amount of days the radon detector was monitoring.

When High Levels of Radon are Detected.

Mitigation efforts can be taken to reduce radon levels in any building. A mitigation system consists of a suction point, radon fan, and a series of pipes that will pull radon from the source and dispel it outside of the structure where it can be diluted by the outside air.

In the US, many states have regulations restricting who can install mitigation systems and in these states a list is available to find a certified contractor in the area. States that do not require contractors to become certified with the state typically recommend using a National Radon Proficiency Program (NRPP) or National Radon Safety Board (NRSB) certified mitigation contractor. While not a state run program, contractors who have either of these certifications have taken and continue to take classes on the best mitigation practices, methods, and equipment.

In Canada, provinces have not yet begun certifying mitigation contractors but will recommend using a contractor from the NRPP’s sister association, the Canadian National Radon Proficiency Program (C-NRPP).


For more information, including world news about radon, you may visit the pages below.

International WHO
Europe ERA
Sweden SSM
Austria BMLFUW
Switzerland BAG
Germany Bundesamt für Strahlenschutz
Ireland RPII EPA
Great Britain PHE
Denmark Sundhedsstyrelsen
Finland STUK
France Radon France