Having just recently completed National radon testing certification I was repeatedly reminded of the EPA radon action level standard of 4.0 pCi/L. Every home inspector and real estate agent who works in an area where radon is a concern is familiar with this standard. What many do not know is that this standard is not health based. It is a mechanical standard based on mitigation technology.
It has never been definitively established at what level or amount of radon gas produces lung cancer. It is know that the more exposure the greater the risk. So therefore by lowering the level in a home significantly reduces the risk.
The method of reduction or mitigation is done most often by active mechanical means. What was found early on in mitigation technology was the radon level could be lowered below 4.0 pCi/L and many times below 2.0 pCi/L. Thus the EPA standard was established.
Since there is no known "healthy" level of radon gas, it is important to;
- Test your home or the home you are purchasing for radon and
- Mitigate if the levels are found to be at or above 4.0 pCi/L.
It is always advisable to not rely on previous tests for several reasons. Radon levels are known to change over time and the reliability of previous test can not be assured. Testing done by certified testing services is always the best method for checking radon levels in a home.
The next time you hear the radon standard 4.0 pCi/L, just remember the less the better.
JRV Home Inspection Services, LLC