We have received a question from a reader asking what radon gas is and how does it impact on a person’s home.

Radon is a naturally occurring radioactive gas whose presence can only be detected by using specialist equipment. It is found in all rocks and soils, but concentrations vary depending on geographical location. The gas normally slowly rises to the surface of theground and is diluted in the atmosphere until it prevents no threat. However if it enters a building it can build up to concentrations which can cause harmful effects.

It is estimated that 10% of lung cancer deaths may be caused by exposure to radon gas in buildings. Due to the dangers of radon all modern buildings are constructed with a radon protective layer under the floor slab along with underground sumps for collecting the gas. These sumps are linked to a covered pipe at the side of the building to which a fan can be connected if high levels of radon are detected. When high levels are detected the fan and flue would be installed and used to suck the radon out from under the building and disposing it to the atmosphere at high level. This is necessary as radon is heavier than air.

In any case building owners should have the radon levels of their buildings checked as the building may have been constructed prior to the use of radon barriers or the installed radon barrier may not be functioning properly. As buildings become more and more insulated and sealed to conserve heat, the downside is that ventilation rates/ air changes are decreasing and any radon which enters the building will find it more difficult to leave.

I had my own home checked when I bought it and the levels were well below the National safe reference level of 200Bq/m3* for homes, the safe levels for workplaces is twice that. But it was interesting to note that radon was present in my home albeit in small concentrations. The check I had carried out cost around 60 euro and involved placing two black radon detectors in different parts of my house (bedroom and living room), for three months, and posting them back to the lab for testing.  There are many companies which will send you radon test kits and I suggest you simple google ‘radon testing’ or check the phone book. More information on radon is available at http://www.rpii.ie/ along with maps indicating high risk geographical locations.

*Note: This unit of measurement (Bq/m3) means that radon is present at a concentration that emits one particle of radiation per second in a cubic metre of air.

2 thoughts on “Radon Gas

  1. Although Radon in high concentrations is harmful, but surely simply opening the window would solve the problem? The requirement in modern homes for natural trickle ventilation in windows and walls ventilates the home. We confused by the Catch 22 requirement of the Building Regulation. On the one hand we are requested to provide an air tight enclosure to reduce heat loss. Spending considerable time, money and attention to detail on finishes to achieve a high seal. We may even go to the extent of requiring an air pressure test. It is certainly common in countries such as Canada where temperatures plummet as low as -30 C in the winter. However on the other hand, local authorities are requesting natural ventilation in the form of trickle vents and/or wall vents to be installed. On a stormy winters night these vents can experience a howling wind being driven into the house. Should your house have high concentrations of Radon Gas, the immediate solution could be simply, leave your windows open for some time and check your Radon Meter on a regular basis to see what the concentration is. This may be a cheaper alternative to the expensive retro-fitting of Radon Membranes and/or Underground Radon Pumps. Radon occurs in everyday building materials, such as, igneous rocks (granite, basalt, schist, shale).

  2. Thanks for your comments. Putting additional ventilators into houses or rooms with high (but not extreme) radon levels can succeed, I have tried this before to solve a high radon levels in a school. But for higher levels of radon this isn’t enough, for the school in question we still had to remove a number of floors and replace them.

    Also the radon detectors don’t give an instant response. They have to be sent to a lab to be analysed and check the how much radon they absorbed.

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