pCi/L Explained: What Your Radon Number Actually Means
You’ve performed a radon test, and now you’re staring at a result that includes a number attached to pCi/L. If you’re testing for the first time or you’re new to radon, that abbreviation probably doesn’t mean much yet. This guide explains what pCi/L stands for and how it relates to radon in your home. From there, we’ll take you through what your specific reading means for your next steps.
What Is pCi/L?
pCi/L stands for picocuries per liter, which is one of the standard ways to measure indoor radon concentration levels. The higher your pCi/L reading, the more radon is present inside your home.
Why is radon measured in pCi/L?
A curie is a very large unit of radioactivity, and radon is measured in picocuries, which are one trillionth of a curie. Picocuries per liter shows how much radioactive material is present in a liter of air.
Breaking down the abbreviations piece by piece can make it easier to follow:
pCi: Picocuries, a measure of radioactivity
L: A liter of air
pCi/L: The amount of radioactive decay present in each liter of air.
So, if your radon test reads 1.5 pCi/L, that means there are about 1.5 picocuries of radon per liter of your home’s air.
What Your Radon pCi/L Levels Mean
Understanding what picocuries per liter measures is just one part of the equation. You also need to know what that measurement means and what your next steps are.
Levels at or above 4.0 pCi/L
The EPA recommends homes be fixed if the radon level is 4.0 pCi/L or greater. So, if your home falls within this range, the best next step is to contact a local radon mitigation company, like The Radon Guys, for a consultation.
Levels between 2.0 and 4.0 pCi/L
Even if your home isn’t at the EPA’s recommended action level, the agency still encourages you to fix your home if your radon levels are between 2–4 pCi/L. Because this range is sometimes treated as a gray area, talking with a licensed radon professional can help you weigh the cost of a mitigation system against your specific situation.
Levels below 2.0 pCi/L
If your radon levels are below 2.0 pCi/L, you likely don’t need mitigation. However, you should still retest your home every two years or after any renovations to ensure radon hasn’t found a new path into your house. Radon levels can change, so retesting is important.
Getting a Year-Round Look at Your Radon Levels
Your home’s radon levels can fluctuate throughout the year, so if you truly want to know where you stand, it’s worth investing in a long-term radon monitor. Levels shift with the weather and the seasons, and they can change even more depending on how well your home is sealed up, so a single short-term test only captures one moment in time.
With a radon monitor, you can get a full picture of your home’s radon levels throughout the seasons, instead of the quick snapshot of a one-off test. This way, you know your averages and you’ll be alerted if something changes.
If you’re interested in a radon monitor, we have a list of devices we trust and recommend to our clients.
What Are Safe Levels of Radon in Tennessee?
There are no known “safe” levels of radon. The danger comes from long-term exposure to higher concentrations, which can lead to lung cancer. Since that risk can’t be eliminated completely, the goal is to limit your exposure as much as possible. That’s why the EPA’s recommended action level of 4.0 pCi/L or above serves as such an important guideline for homeowners.
Lowering Your Radon Levels
The only way to reliably reduce your home’s radon concentration is with a professional radon mitigation system. These systems are designed to stop radon gas before it even enters your home by drawing it up from beneath your foundation and safely venting it outside above your roofline.
Because every foundation and soil type is different, a mitigation contractor designs the system around your specific home rather than installing a generic setup. Once the system is running, a follow-up radon test confirms your levels have dropped to better levels.
Trust Your Local Tennessee Radon Experts
If you need help deciphering your radon number, The Radon Guys can walk you through your results and recommend the right next step, whether that's a follow-up test or a full mitigation system. Contact us today to get a clear answer and peace of mind about the air you're breathing.
