Professional Radon Testing in New York City & Surrounding Area
What This Inspection Covers
Our NRPP-certified radon measurement professionals conduct short-term and long-term radon tests following EPA and ANSI/AARST measurement protocols. The inspector places calibrated test devices (charcoal canisters for short-term, alpha track detectors for long-term) in the lowest livable area of the building under closed-building conditions. Devices are shipped to an accredited laboratory for analysis; results are delivered in the written report.
Who Needs This & When
Radon testing is recommended or required when: purchasing any residential property (EPA recommends testing all homes regardless of age or location); you live or plan to live in a basement apartment (ground-floor and below-grade units have higher exposure risk); you are renovating a basement or adding a lower-level living space; your prior test showed elevated levels and you installed a mitigation system (re-test to confirm efficacy); or you have elevated radon exposure concern due to local geology.
Inspector Credentials
All radon testers hold the NRPP (National Radon Proficiency Program) Certified Radon Measurement Professional designation. Test devices are calibrated and sent to a NRPP-listed accredited laboratory for analysis.
What You Get
Written radon measurement report within 48 hours of laboratory turnaround. Report includes: test method (short-term vs. long-term), device placement locations with photos, closed-building conditions attestation, laboratory results in pCi/L (picocuries per liter), comparison to EPA 4 pCi/L action level and NYS 20 pCi/L mandatory reporting threshold, and recommendations (no action / mitigation recommended / mandatory mitigation). Report is suitable for real estate transactions and for NYS DOH reporting.
Frequently Asked Questions
What is the EPA action level for radon?
The EPA recommends taking action to mitigate radon if your test result is 4 picocuries per liter (pCi/L) or higher. At 4 pCi/L, the EPA estimates a lifetime lung cancer risk comparable to smoking half a pack of cigarettes per day. The average indoor radon level in the US is 1.3 pCi/L; the average outdoor level is 0.4 pCi/L. Any level above 2 pCi/L is worth monitoring and mitigation consideration.
Is there a mandatory radon reporting threshold in New York State?
Yes. Under 10 NYCRR §16.140, New York State requires reporting of radon measurements at or above 20 pCi/L to the NYS Department of Health. This is a mandatory reporting requirement — the property owner and NYS DOH must be notified. At 20 pCi/L, mitigation is strongly recommended and in some contexts mandatory. Our reports flag all results at or above both thresholds (4 pCi/L EPA action level and 20 pCi/L NYS mandatory reporting threshold).
What is a closed-building radon test?
A valid short-term radon test requires closed-building conditions: all windows and exterior doors must remain closed (except for normal entry/exit) for 12 hours before and throughout the measurement period. HVAC systems can run but no fresh-air exchange or whole-house ventilation. Our inspectors document closed-building conditions in the test report and will not certify results if conditions were not maintained. Real estate transactions typically use short-term tests (48–96 hours) under closed-building conditions.
Do NYC apartments have elevated radon levels?
Radon is less common in high-rise NYC apartments than in single-family homes or ground-floor units, because radon enters through foundation contact with soil. However, basement apartments, ground-floor units, and buildings in northern Manhattan, the Bronx, and areas of Staten Island with more soil contact have measurable radon risk. The EPA recommends testing any home — including apartments — especially below the third floor. NYC's older building stock (stone and brick foundations) can allow soil gas infiltration.