Typically potentially-deadly threats in a home are fairly easy to recognize. Dangerous situations such as fuel stored too close to a heating source, faulty wiring, or unsafe handrails can be spotted and mitigated. But what about threats that are invisible, silent, odor and taste-free, and cannot be felt? There are such threats in the world that affect many homes and without proper testing may go undetected for decades. One of the most common of these hidden threats is the presence of radon gas within a building.

The chemical element radon is a radioactive gas that results from the decaying process of radium, thorium, and uranium within bedrock formations and groundwater. As a noble gas, radon rises up through the porous dirt and typically escapes into the air. However, if there is a place for it to accumulate, it can then become a health hazard. This first became evident in uranium mines, as high levels of radon were detected and began to be associated with health risks, primarily as a carcinogen causing lung cancer. It wasn't until much later that it was discovered that the escaping gas could also accumulate in buildings, usually those with basements.

In order for radon to accumulate in sufficient quantity to present a significant health risk, there are a number of conditions that need to be present.

Geological source

As the presence of radon is a result of the decay of other radioactive materials, it is necessary that these elements be present in the ground. While radium, thorium, and uranium are very widespread and present in almost all locations, the abundance of these deposits determines the amount of production of radon gas.

Pathway and concentration

As radon gas is produced in the bedrock and groundwater, it then naturally rises to the surface.  The natural tendency is to find the path of least resistance. In addition to naturally occurring porous substances such as sand or gravel, disruption of soil during excavation for building can also greatly contribute to the ease with which the gas can rise upward. Constructing a building on these sites then provides a space where the gas can accumulate.

Human behaviors

While buildings allow accumulation, it is the tendency of humans to seal up the buildings and remain inside that creates the hazard. Changes in habits, such as using air conditioning versus opening a window, have caused the presence of radon in dwellings to increase.

While radon can be detected and mitigated, the most important step is to identify it. Testing of new structures and periodic retesting of existing ones is therefore critical to keep this risk in check. For more information about residential radon testing, contact a local professional.