What is Radon and Radon Mitigation?

One of our Commercial Radon Mitigation Jobs. Drilling two 4-1/2 inch holes at a 15 degree downward slope through 26 inch solid concrete foundation wall of a multi story building in downtown Syracuse.

What the heck is Radon anyways? Radon is a naturally occurring radioactive gas that comes from the natural breakdown of uranium in the earths crust. Radon is found in rocks and soil and can also be found in groundwater, particularly in deep wells that are drilled in high radon areas.

What is Radon Mitigation? Radon mitigation is any means by which radon gas is reduced. The result of the steps taken to reduce radon in a home or building is typically referred to as a radon mitigation system. A radon mitigation system is composed of any one or more of a number, of structural and or non-structural measures, undertaken to reduce the the level of radon. There are many types of radon systems and the basic components radon systems vary depending on the type and design of the system.

Why mitigate radon? The purpose or goal of radon mitigation is to remove or reduce the potential hazards of breathing high concentrations of radon gas inside a home or occupied building. Radon does not pose much risk in the outdoor air but radon gas, if it builds up to high concentrations inside dwellings, can become a health problem.

What is the health risk associated with breathing radon? As radon decays it produces radioactive particles that may cause damage to delicate lung tissue when breathed in. When radon builds up to high concentrations inside some buildings it can pose a health hazard. The World Health Organization says, “Recent studies on indoor radon and lung cancer in Europe, North America and Asia provide strong evidence that radon causes a substantial number of lung cancers in the general population.” For improved safety, the United States EPA recommends that you take action to reduce your home’s indoor radon levels if a radon test averages 4 pCi/L or higher.

What is a high level of radon? In 10 Uranium mines in Utah, from 1949 to 1950, radon was measured ranging from 100 pCi/L to 50,000 pCi/L. Source. Those miners had a higher rate of lung cancer than the average population, however close to 100% of them were also chain smokers. While in the mines, they were also continuously exposed to terrible breathing conditions including, fine ore dust, low oxygen and high carbon monoxide and diesel exhaust fumes.

According to the EPA, the average indoor radon level in US homes is about 1.3 picocuries per liter (pCi/L) and the average outdoor level is about 0.4 pCi/L. Source

How does radon get into houses? Radon and other soil gases while underground are under pressure that pushes them towards the surface. Radon is pushed up through the ground, simply following the path of least resistance. When it reaches the ground surface radon gas dissipates into the air, harmless for the most part. When a house or building sets on the ground the rising radon comes into contact with the underside of the house, as the radon is still under positive pressure, it is pushed into the building, typically, right through the porous concrete or openings in the floor. In addition to the radon being pushed into the home or building by positive soil pressure, most buildings and homes maintain some negative pressure which actively sucks the radon in. Most homes remain closed up for the most part and the radon in some cases builds up to much higher concentrations than what is present in the outdoor air and becomes a potential health risk.

How does a radon mitigation system work?

Mitigation of radon in the air is accomplished through ventilation, either collected below a concrete floor slab or a membrane on the ground, or by increasing the air changes per hour in the building. Mitigation of radon from domestic water supplies is also sometimes needed usually when deep wells are present in high radon areas. Treatment systems using aeration or activated charcoal are available to remove radon from domestic water supplies.

The most common radon system utilized in homes in central New York is a sub-slab depressurization system.  Typically a radon fan, located in an attic or outside the building and is connected to 3 or 4 inch PVC vent pipes to draw air out from under a basement, crawl space or slab on grade concrete slab. Prior to the radon mitigation system being installed the radon gas from the soil is pulled into the house by a slight negative pressure that exists in most homes. After radon mitigation, the radon fan and vent system pull the radon laden air from the soil areas below the house and vent it to the outdoors, bypassing the interior of the home. This type of mitigation causes the, air below the house becomes negative in pressure as compared to the air inside the house and the radon gas now simply follows the path of least resistance up and out the radon vent pipes. 

“Radon mitigation” is also referred to as:


These are all synonymous terms for the most part, referring to the systems installed or modifications to those systems installed in a home or building to reduce the radon levels. In central New York and Syracuse areas, “radon mitigation” is the most commonly used term.

This EPA online PDF booklet answers the question, What is radon mitigation?

The US Surgeon General and EPA recommend testing for radon and reducing radon in homes that have high levels. They both say “Fix your home if your radon level is confirmed to be 4 picocuries per liter, pCi/L, or higher.”

Click on following link to the EPA PDF booklet: “A Consumer’s Guide to Radon Reduction.” Most US states and developed countries around the world have similar radon safety recommendations.

Why does radon vary from house to house? Primarily the concentration of radon in the soil varies from building lot to building lot and from one geological soil type to another. Additionally, the way a house is built can be a factor. In older, drafty homes and buildings, radon is generally not as much of a problem due to the fresh air exchange or movement of air which is the source of those drafts, i.e. the leaky windows, doors and exterior walls and roof. In contrast, newer, high efficiency, “air tight” homes and older homes that have been upgraded with extra insulation, air sealing, new windows and doors because they are more “air tight” and tend to trap and hold more radon gas.

What is the procedure for radon mitigation? If a radon test comes back high, with an average radon level of 4.0 pCi/L or higher, the consensus recommendation is to have a radon mitigation system installed. No need to panic, radon mitigation is commonplace throughout the United States and especially so in Central New York.

Radon in New York is found just about everywhere but some areas have higher concentrations. Central New York, specifically Cortland county, has the highest average radon levels found in New York. In the greater Syracuse area of Central New York, generally speaking, south of New York State Thruway I-90, a little more than half the homes have high radon – above 4 pCi/L, for which radon mitigation is recommended. North of I-90 most homes have less than 4 pCi/L a level which is generally considered acceptable. Please be aware however, geographical location is no guarantee of low radon. The only way to know for certain whether your house is recommended for radon mitigation is to do a radon test, if radon tests at 4.0 pCi/L or higher, radon mitigation is recommended.

New York State High Radon Area Counties

Following is a list of New York State counties with high radon: Albany, Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung, Chenango, Columbia, Cortland, Delaware, Dutchess, Erie, Genesee, Greene, Herkimer, Lewis, Livingston, Madison, Montgomery, Oneida, Onondaga, Ontario, Orange, Otsego, Putnam, Rensselaer, Saratoga, Schenectady, Schoharie, Schuyler, Steuben, Sullivan, Tioga, Tompkins, Ulster, Washington, Wayne, Wyoming and Yates county.

Where are the highest levels of radon in New York? New York State maintains a list of the counties in New York State that have the highest levels of radon gas. This is based on radon test results sent to NY State from radon testing laboratories.  Several Upstate New York counties rank high on the list and Cortland County is number one. The average radon in basements of Cortland county is 14.38 pCi/L. The EPA action level is 4.0 pCi/L. Compare that to other central NY counties with high radon levels in basements of peoples homes such as Chemung county at 12.38 pCi/L, Onondaga county at 8.08 pCi/L, Madison county at 6.13 pCi/L and Cayuga county at 4.70 pCi/L.

Radon in homes can be fixed. Excessive radon levels can be successfully mitigated in every type of home. A Best Radon Systems has successfully mitigated many hundreds of homes. Most of the radon mitigation systems we install reduce the radon to below 2 pCi/L. We provide free, on site radon or phone mitigation consultations and estimates for the greater Syracuse, NY area. The types of mitigation systems vary depending on the radon source and type of home. We can explain the options for reducing radon in your home and put together a plan that effectively mitigates the radon hazard to ensure the safety of all occupants.