You've been monitoring your radon levels for a while, but what do these numbers mean?
Should you be worried?
Is it necessary to install a radon pump?
Should you just open the window more often?
Let's clarify a few things first:
It's important you have measured correctly, and have obtained enough data.
If you are using a Corentium Home, Wave Radon, Wave Plus, View Radon, or View Plus to measure your radon levels, we recommend you measure in one location for at least 30 days, to understand the behaviour of radon in your environment and to obtain enough data.
The longer you measure for in one location, the more accurate your readings will be. You should always consider your long term average when deciding to pursue radon mitigation action.
You have seen consistently high radon levels for approx. 30 days or more.
Radon levels fluctuate naturally. If you see an irregularly high reading of radon one day, it is generally nothing to be alarmed by.
It is best to observe the data your Airthings device collects over longer periods of time. Once you notice you have high readings, it is important to monitor them closely and check whether they stay consistent.
When to contact a radon professional
Our radon level chart below offers guidelines on what radon levels are acceptable (in both picocuries and becquerels for imperial/metric measurement system) and what levels warrant taking mitigation action:
Why is ventilation and sealing cracks effective?
Radon exists everywhere, even in the open sea, but radiation only becomes a problem when it starts concentrating. It is easier for radon to accumulate in well-insulated office buildings or homes than in areas that are open or constantly ventilated.
Radon particles have a half-life of 3.8 days. This means it’s possible to reduce concentration with proper ventilation alone. As ventilation increases, radon concentration will decrease.
In areas where there’s constant ventilation, radon levels will tend to align with normal concentrations outdoors. Try to ventilate and measure for at least a week in a particular room to see if levels get closer to normal outdoor values (~10 Bq/m3).
While it is recommended to implement mitigation measures in rooms where levels are much higher than the reference levels, values slightly above average are not as harmful if you spend a little time in there. In other words, if you have a room with an average radon concentration of 350 Bq/m3 but only use the room for storage or pop in once in a while, you will be safe. However, you should always make sure the radon is not seeping into other areas of the building. You can find more information here from a case study about radon toxicity.
What if I still have high readings after experimenting with ventilation and sealing cracks?
Have you measured for long enough since you tried lowering your radon levels?
If you have tried to ventilate and seal cracks, you should continue to measure again for at least 1 week, to see the effects of the mitigation.
If you are genuinely still seeing high levels of radon after this, it's time to consider contacting a radon professional.
Contact a radon professional if you see:
Moderately high levels for longer than 3 months
100 - 149 bq/m3
2.7 - 4 pci/l
Very high levels for 1 month
According to the World Health Organization (WHO) on its 2009 Handbook on Indoor Radon, there are over 40 case-control studies that have contributed to understanding the link between radon exposure indoors and lung cancer. These studies have also helped to establish what normal levels of radiation are or, more accurately, those considered acceptable.
Radon is leading cause of lung cancer among non-smokers. Each country or region is in charge of developing a national plan for mitigation and control of radon gas; these plans are “aimed at minimizing exposure of the population to radon”. The European Union has established some guidelines that take into account the soil conditions.
There are factors that affect indoor radon levels, like weather conditions in your area or the time of the year. In zones far from the equator, there are normally higher levels during the winter than the summer because in the cold weather most people ventilate less.
The Radon and Health Fact sheet from the WHO states that:
“Radon levels in existing homes can be reduced by increasing under-floor ventilation, installing a radon sump system in the basement or under a solid floor, avoiding the passage of radon from the basement into living rooms, sealing floors and walls, and improving the ventilation of the house. Passive systems of mitigation have been shown to be capable of reducing indoor radon levels by more than 50%. When radon ventilation fans are added radon levels can even be reduced further.”
National agencies normally recommend the most cost-efficient methods to reduce radon, should levels not be reduced by simple ventilation. If the problem is severe, many countries offer financial support or tax credits to help homeowners with the installation of active mitigation methods.
There is usually a list of certified radon professionals in each country that can help you reduce the concentration of radon. Many national agencies provide this directorate or point you in the right direction to find the person or business who can help you. Search for “radon” on your government website, otherwise turn to the local Health and Safety authorities for more information and help.