Ventilate more! To get rid of radon coming from building materials and construction materials, an increase in ventilation rate to double rate could halve the radon levels.
If you have radon, it is important to have a balanced ventilation system, i.e. approximately same amount of mechanically supplied air and exhausted air. If you have a negative pressure there is a risk that radon is sucked in through leaks in the building’s envelope, a balanced ventilation system prevents this from happening.
If you have got the results from investigation that you have radon in his house, how do you know how much more you should ventilate? And for how long? In the long run it can become a costly issue if you’re going to have a high level of ventilation and the need to examine the radon concentration by conventional methods at regular intervals.
Source: SP Sveriges Tekniska Forskningsinstitut and www.radonguiden.se