Radon is basically a soil gas caused by the uranium decay in the soil. It is a misconception that only some places have radon gas however every place i.e. whether inside or outside have radon gas present in them. The average outdoor air concentrations of radon gas in the United States are between 0.4 and 0.7 pCi/L. On the other hand, the average indoor radon level in the United States is right around 1.7 pCi/L. However, EPA has set an action standard of around 4.0 pCi/L. meaning that if your indoors have a level of around 4.0 pCi/L it is recommended that you instantly mitigate your homes. Because radon gas is the 2nd largest cancer-causing agent in humans and 1st in non-smokers. Each year around 25000 people die because of this. So, by keeping this figures World Health Organization has set an actionable limit to 2.7 pCi/L. And because of this EPA has also made updates and said that if you see the Radon levels to lie between 2.0 and 3.9 pCi/L. you have to take action but in USA the limit is still 4.0 pCi/L.
Many people find it difficult to test Radon because it is odorless, tasteless and colorless and none the less dangerous too. So, by the time you realize the presence of Radon in your facility it becomes already too late. So, EPA has set a standard to test your homes at least every 2 years i.e. whether you change your property or sell the house or build a new one you have to make the testing every 2 years. Sometimes the local authorities present you with a lot of offers to test your houses and the govt. also gives you incentives or offers for testing. It is mostly recommended that you make the testing in the month of January. Testing may usually cost from like 25$ to 150$ which is considered a very small price to pay with respect to the problems you can get in to because of your negligence.
Radon mitigation as explained above why it is needed and what damages it may cause if not paid heed to this? So mostly Mitigation is done by active soil depressurization. It is often done by air exchange etc. but this method is extremely rare also water mitigation is also done but that also is very rare as compared to that of Radon Soil mitigation.
Here the Question arises How does Radon Mitigation Work? Radon mitigation is caused by the difference in pressure i.e. pressure in the houses and pressure in the soil is difference along with other factors like temperature, wind etc. So as we know we uses exhaust in our houses which generates a negative pressure which is one of the major reason of sucking out the radon from the soils and also radon as it is in soil and its concentration is higher it will move towards the area of lower concentration and as the building is confined so it will move there rather remain still in the soil it moves upward towards the building structure.
Radon Has is mitigated when the technician seals all the cracks all the exits and creates a negative pressure in the soil by the help of a Radon Mitigated Fan and then releases all the Radon Gas above the roofline according to EPA standards.