High radon concentrations can be reduced by simple building works. International guidance suggests that radon levels should be reduced if they are more than 100–300 Bq per m3.
A number of methods can be used to reduce radon levels by decreasing entry of radon into the home from the ground. Some methods work by slightly increasing the air pressure within the home, whereas others are based on diluting the air entering the home from the ground with outdoor air or on drawing air from the ground beneath the home and pumping it out to the atmosphere. Most radon reduction systems require the use of small electrical pumps.
After any work is done to reduce radon levels, you should have a repeat test to check that levels are low. You should follow instructions about periodic checks and maintenance of your radon reduction system.