Radon is not a new thing. There has always been radon gas in the air. With the advent of cheaper and more readily available testing methods, we have become more aware of occupant exposure to radon gas. Most of the time it is during the home sale process that homeowners become informed of radon in their basements. Home inspectors can offer certified radon testing as part of the inspection. Home test kits available at hardware store, online or from government health departments are very reliable as long as the user follows the directions.
The Environmental Protection Agency has determined that an average radon concentration of 4.0 picocuries per liter of air is an action level where the home should be fixed. In central New York, the odds are above 60% that a home will have elevated radon. According to the New York State Department of Health, Onondaga County will be about 65% and Cortland County will be above 70%. That doesn’t mean that you can assume that your home has radon gas above the EPA action level. Every home needs to be tested. Even within Onondaga County, there are areas that have consistently tested higher than others. Manlius, Fayetteville and Camillus are areas where testing has shown that more homes experience elevated radon and as a result more mitigation systems are present. A homeowner cannot assume that because their neighbor has or hasn’t tested elevated for radon that they are in the same situation.
Every home is different in the way radon gas is induced into the structure. Radon gas is about 4 times heavier than air, so it is not naturally rising up into your home. Because every house has a slight negative pressure associated with it, the gas is pulled into the house. As we exhaust bathroom fans, dryer vents, furnace or hot water heaters we create a slight negative pressure inducing radon gas to be pulled into the house. Even atmospheric conditions will cause a house to become negative. During storms or high winds, a house can achieve a significant negative pressure. Once it is in the house, it can be measured in concentration and the occupants are exposed to those elevated levels.
Why are we just recently worrying about radon gas when it has been around forever? Within the last 15 years, testing has become more readily available and more inexpensive. People are also becoming more aware of what indoor pollutants. But also building practices changed in the late 1970’s and early 1980’s. As homes were made tighter to save energy, natural ventilation was reduced and more radon gas was trapped in the house. What we used to call drafts, could be considered low radon concentration air infiltrating the house reducing the average radon concentration in the occupied space. Homes were reducing the average radon per liter of air by dilution with low concentration air without the occupant knowing about it. A homeowner could do the same technique now, by opening all the windows in the basement. This would reduce the radon average in the home, but would not be practical in the middle of January.
Radon Mitigation reduces occupant exposure by collecting radon gas from under the house and exhausting it outside. This is accomplished typically with PVC pipe and an inline fan. A radon mitigation system uses negative pressure to attract radon gas to a collection point under the concrete in the lowest level of the home. Future post will explore radon mitigation techniques.
For more information about professional radon testing or where you may acquire a low cost or free radon home test kit. Please call or email:
Barry Bourgeois — 315-382-2050