EPA predicted potential
Zone 2 indicates predicted average indoor screening levels of 2–4 pCi/L. Individual homes may be above or below that range.
The bottom line
Test the house. Do not test the ZIP code.
EPA’s county map describes potential, not the level inside a particular house. In McNairy County, the public state dataset offers no local 2022–2023 measurements to narrow that uncertainty. A short-term test is the first useful fact a buyer or homeowner can create.
Dashboard events, 2022–2023
The state map displayed “No Events” for McNairy County on three checks. The regional band charts cannot substitute for a county count.
Certified pros based in-county
No NRPP- or NRSB-listed professional was found in McNairy County when checked October 16, 2026.
Risk profile
Moderate potential. Almost no local measurement trail.
These two facts belong together: the county-level prediction warrants testing, while the local dataset cannot tell residents what homes are actually measuring.
McNairy County is EPA Radon Zone 2.
Zone 2 denotes predicted average indoor screening levels of 2–4 pCi/L. It is a planning classification—not a pass/fail result for any address.
“No Events” across 2022–2023
On three observations—two at Year “(All)” and one at 2022—the Tennessee Department of Health dashboard identified McNairy County and returned “Average Radon Level: No Events.” Median and maximum were blank.
The lower charts stayed at health-region level when McNairy County was selected, so their counts and percentages are not county data.
No data is not low data.
The dashboard result means no test events were mapped to McNairy County in that two-year dataset. It does not mean homes measured zero, or that there is no radon risk. A third-party marketing page’s claimed 10.00 pCi/L “Selmer average” was excluded because it came from one user-submitted Jackson test, 35.3 miles away.
Building codes
Selmer’s code stack is real—and not simple.
Two layers appear in the municipal code. Neither supplies a clean, affirmative local requirement to build new homes with radon-control features.
2012 IRC, “including appendix chapters”
- Adopted at §12-501; latest listed replacement is Ordinance #668, March 2018.
- The 2012 radon appendix is Appendix F, so it is nominally included.
- But Appendix F applies where the jurisdiction requires radon-resistant construction, and no separate mandate was found.
2018 IRC plus Appendix Q only
- Title 12, Chapter 8 was added by Ordinance #695 in May 2023.
- It codifies state rules for one- and two-family dwellings and townhouses.
- State deputy building inspectors conduct those inspections; the radon appendix is not named.
Working conclusionNeeds local confirmation
Radon-resistant new construction appears optional in Selmer.
Where Selmer’s adopted codes conflict, §12-803 says the most stringent provision controls. Even so, the research found no affirmative radon mandate. Confirm the town’s practical interpretation with the building inspector or recorder before relying on it for permitting.
Unincorporated countyHistoric source only
The latest located list showed McNairy County opted out.
A circa-2010 MTAS jurisdiction list classifies McNairy County as opted out of the State Fire Marshal residential inspection program, with Michie and Stantonville also opted out and Selmer exempt. Because opt-outs require renewal, this old list cannot establish current status. If it still holds, unincorporated areas have neither local residential enforcement nor state residential inspections.
Other local rules
No county- or Selmer-specific radon rule was found.
The search found no local radon rule for public buildings, schools, or real-estate transactions. Tennessee’s school policy is described as encouragement rather than a testing mandate. The enactment status of a 2018 proposal to add radon to annual school indoor-air evaluations was not verified.
For homebuyers
Make radon a contract question—not a closing surprise.
No McNairy-specific point-of-sale testing rule was found. That leaves the inspection period and contract terms to do the work.
Include a radon inspection contingency.
Tennessee’s Residential Property Condition Disclosure materials advise buyers to include radon inspection contingencies. The seller’s disclosure is not a warranty or a substitute for an inspection.
Test even when the seller knows of no issue.
Sellers must disclose known material defects, including known hazardous-material issues, but an untested home can have no known result to disclose. Tennessee does not require point-of-sale radon testing.
Ask new-home builders what was installed.
No local mandate was confirmed. For the county’s limited new construction, ask whether a passive radon system, gas-permeable layer, sealed slab penetrations, and future fan provision were included voluntarily.
Retest after major changes.
Foundation work, HVAC changes, weatherization, or a finished lower level can change airflow. A prior result describes the house under its prior conditions.
Tennessee residential disclosure form ↗ · Tenn. Code Ann. § 66-5-210 (disclosure form)
Housing context
An owner-heavy, mostly existing-home market.
The case for local radon education is tied more to transactions and long-term occupancy than to a building boom.
01.7%
Owner-occupied
McNairy County had 12,398 housing units and a median owner-occupied value of $161,800 in the 2020–2024 Census profile.
26
Building permits in 2025
New construction is a trickle. Testing existing homes matters most right now.
+1.4%
Population change since 2020
Population rose from 25,866 in the 2020 census to an estimated 26,236 on July 1, 2025.
22.7%
Residents age 65+
For long-term occupants, cumulative exposure makes periodic testing especially relevant.
How do I find a certified radon professional in McNairy County?
Tennessee doesn't license radon testers or mitigators, so national certification is the best way to check qualifications. The Tennessee Radon Program points residents to two directories: search them by ZIP code and widen the radius if nothing is listed nearby.
We don't recommend or rank companies. Before you hire, check the certification number in the directory yourself and ask for a follow-up test after any system is installed. Questions to ask a radon professional.
Answers in brief
McNairy County radon FAQ
Is McNairy County in a high-radon area?
McNairy County is in EPA Zone 2, which indicates moderate predicted potential and average indoor screening levels of 2–4 pCi/L. The zone cannot predict a particular home’s result; testing is the only way to know.
Does “No Events” mean there is no radon here?
No. It means the Tennessee dashboard had no test events mapped to McNairy County in its 2022–2023 dataset. It is a measurement gap, not a zero reading.
Does Selmer require radon-resistant new construction?
No affirmative requirement was found. The working conclusion is that radon-resistant construction is optional, but Selmer’s layered code language should be confirmed with the building inspector before a permitting decision.
Is radon testing required when a home is sold?
No McNairy-specific testing mandate was found, and Tennessee does not require a point-of-sale radon test. Buyers can protect the inspection window by adding a radon contingency.
Are local certified testers available?
None were found based in McNairy County in NRPP or NRSB directory checks on October 16, 2026. The nearest NRPP measurement listings were about 68 miles away in Memphis; NRSB returned no professionals within 100 miles.
Research trail
Primary and supporting sources
Dashboard and professional-directory observations were checked October 16, 2026. Code and Census dates are noted in the text.
- Selmer Municipal Code, Title 12 — official MTAS codification, Change 8 through June 29, 2023.
- MTAS residential-inspection jurisdiction list — historical, approximately 2010; not proof of current status.
- MTAS: Opt-Out Cities — reviewed September 15, 2025.
- MTAS: Energy Code—Nonexempt Cities — reviewed September 24, 2025.
- Tennessee Department of Health, Tennessee Radon Testing dashboard — three live observations.
- EPA Map of Radon Zones — zone definitions and limitations.
- EPA Map of Radon Zones: Tennessee — supporting county designation.
- NRPP Find a Professional — ZIP 38375 search.
- NRSB Find a Professional — 100-mile Tennessee and Mississippi searches.
- Tennessee Residential Property Condition Disclosure.
- 50-state school radon law review.
- U.S. Census QuickFacts: McNairy County.