York RadonPractical radon guidance for York, PA homeowners

After a high radon result

Your Radon Test Came Back High. What Now?

A result at or above 4 pCi/L is the EPA's action level — the point where their guidance changes from “consider fixing” to “fix your home.” This page is the order to work through it: what to do first, how to confirm the number, and when mitigation actually enters the decision.

First: is this an emergency?

It calls for timely action, not panic. That distinction is worth being precise about, because a high number on a page can feel like an alarm going off.

Radon's health risk comes from long-term exposure, not from a single day. The EPA is direct about both parts of that:

“There are no immediate symptoms from exposures to radon.”

“Lung cancer would usually occur years (5-25) after exposure.”

Source: U.S. EPA, “What Are the Health Effects from Exposure to Radon?” (epa.gov/radon/what-are-health-effects-exposure-radon)

That is why the EPA's own guidance is a sequence — confirm the result, then decide — rather than an instruction to leave the house tonight. It is also why letting it sit for a year is the wrong call. Every month at an elevated level is exposure you could have avoided.

General information for homeowners, not an assessment of your specific property or an evaluation of anyone's health. Health questions belong with a healthcare professional.

Where your number sits

Direct from the EPA: “Fix your home if your radon level is 4 picocuries per liter (pCi/L) or higher. Consider fixing if your level is between 2 and 4 pCi/L.”

Source: U.S. EPA, “EPA Map of Radon Zones and Supplemental Information”

At 4 and above, a 5 and a 20 get the same instruction: fix the home. Where the size of the number genuinely matters is in how you confirm it — and that is the next section.

If you want the full scale, including what the ranges below 4 mean, see what your radon number means. This page assumes you already have a number at or above the action level.

The sequence

1. ConfirmFollow up a short-term result with a second test
2. Choose the testLong-term for accuracy, or a second short-term for speed
3. Read both resultsAverage two short-term tests; a long-term result stands alone
4. Decide on mitigationConfirmed at or above 4 pCi/L is the EPA's fix-the-home range

Free York homeowner resource

Your result came back high. Take the checklist with you.

That sequence is the short version. The free Radon Ready Kit is the working copy: the same decision tree on one page, space to record both test results, the questions to ask each contractor, and a worksheet for comparing up to three quotes side by side.

Get the Free Radon Ready Kit

16 pages, PDF, emailed to you. No cost, and no contractor is given your details.

Step 1 — Confirm the result

EPA guidance: “If your result is 4 pCi/L or higher, take a follow-up test … to be sure.”

Source: U.S. EPA, A Citizen's Guide to Radon (EPA 402/K-12/002)

A short-term test measures a few days. Radon moves with weather, season, and how the house is being used, so one short test is a snapshot rather than a settled answer. Confirming it before spending money on a system is the point of this step.

If your high result already came from a long-term test — more than 90 days — you can skip ahead. That measurement already reflects something close to your year-round average, and the EPA's guidance is plain: “Fix your home if your long-term test result is 4 pCi/L or more.”

Step 2 — Which follow-up test?

Two legitimate options, and the EPA describes the trade-off rather than picking for you:

Long-term test

“For a better understanding of your year-round average radon level, take a long-term test.”

More than 90 days. More accurate, slower.

Second short-term test

“If you need results quickly, take a second short-term test.”

Faster, less representative of the whole year.

If your result is more than twice the action level

Above roughly 8 pCi/L, the EPA stops describing a trade-off and makes a recommendation:

“The higher your initial short-term test result, the more certain you can be that you should take a short-term rather than a long-term follow up test. If your first short-term test result is more than twice EPA's 4 pCi/L action level, you should take a second short-term test immediately.”

Source: U.S. EPA, A Citizen's Guide to Radon

In plain terms: at that level, waiting three months for a long-term test is the wrong trade. Start a second short-term test now.

Whichever you choose, the radon testing guide covers how to run the test properly — placement, closed-building conditions, and what Pennsylvania requires of certified testers.

Step 3 — Read the two results together

If your follow-up was a second short-term test, average the two. EPA guidance: “Consider fixing your home if the average of your first and second test is 4 pCi/L or higher.”

If your follow-up was a long-term test, that result stands on its own: “Fix your home if your long-term test result is 4 pCi/L or more.”

You may notice the EPA says “consider fixing” for the averaged pair and “fix” for a long-term result. That is the EPA's own wording, quoted as written — a long-term test carries more weight because it covers more time. Source: U.S. EPA, A Citizen's Guide to Radon.

When mitigation enters the decision

Once a high result is confirmed, mitigation is the EPA's recommended path. A system doesn't mask the problem — it reduces the radon entering the house, typically by drawing soil gas from beneath the foundation and venting it outside above the roofline.

Two things worth understanding before you call anyone: how a mitigation system actually works, including how you confirm afterward that it worked, and what mitigation typically costs in Pennsylvania and what drives the price up or down.

Your radon number is not what sets the price. Two homes with very different readings often get near-identical systems; the building is what moves the cost.

If this is a home sale or purchase

A transaction changes two things: who should do the testing, and how much time you have.

Use a professional. The EPA recommends hiring a qualified tester when you're buying or selling a home, rather than relying on a kit you run yourself.

Time pressure is real, and it shapes the choice above. A long-term test takes more than 90 days, which most closings can't accommodate. That is precisely the situation the second short-term test exists for.

Disclosure applies in Pennsylvania. The official seller disclosure form regulation, 49 Pa. Code § 35.335a, names radon specifically among hazardous substances a seller must address, and Pennsylvania DEP guidance states that if a home has been tested for radon, the results must be disclosed when the home is sold. More detail on radon in Pennsylvania.

General information, not legal advice. Disclosure obligations can be fact-specific — a real estate agent or attorney is the right person to ask about a particular transaction. Sources: CDC, “Testing Your Home for Radon,” quoting the EPA's recommendation; 49 Pa. Code § 35.335a.

Verify anyone you hire

Pennsylvania requires certification from the Department of Environmental Protection for anyone who tests or mitigates radon professionally — it is not optional, and it is not something a contractor's word establishes.

DEP's own instruction: “To verify certification, check for a current DEP ID Card and/or certification certificate.”

Source: Pennsylvania DEP, Radon Services Directory. Certification requirement: 25 Pa. Code Chapter 240.

The state publishes the current list of certified individuals and firms. Check the person or company yourself in the PA DEP Radon Services Directory before work is performed. Someone certified to test is not automatically certified to mitigate — those are separate certifications.

For what professional testing involves locally, see radon testing in York, PA.

York Radon does not perform radon testing or mitigation, does not employ certified technicians, and does not certify providers. Pennsylvania DEP is the certifying authority.

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