Radon Explorer · New Jersey
Know what’s in the air you breathe
Professional radon measurement for homes, multifamily properties, schools, childcare facilities, and offices throughout New Jersey.
Stage 01 · Origin
It begins deep underground
Uranium occurs naturally in rock and soil beneath buildings around the world. Over time, uranium decays through a natural radioactive process.
- Uranium
- Radium
- Radon
The green glow is a storytelling device. Uranium in soil does not look like this.
Stage 02 · Decay
A slow natural process
As uranium decays, it forms radium. Radium can then decay into radon — a radioactive gas that has no color, smell, or taste.
Each step in the chain happens on its own timescale, from billions of years down to days.
Stage 03 · Movement
Radon moves through the ground
Radon gas can travel through openings in soil and enter buildings through differences in air pressure.
The gas shown here is a visual representation. Radon itself is invisible.
Stage 04 · Entry
Small openings can become entry routes
Radon can enter through cracks, joints, gaps around pipes, sump openings, and other pathways in contact with the ground.
Entry routes vary building to building. No single opening is always the main source.
Stage 05 · Exposure
You cannot see, smell, or taste radon
A building can look completely normal while having an elevated radon concentration. Measurement is the only reliable way to know the level.
People live, sleep, study, and work in a building without any sign that the concentration is high or low.
Stage 06 · Variation
Radon levels can change
Radon concentrations may vary with weather, ventilation, pressure differences, building conditions, and time. A properly performed measurement helps provide meaningful information about the building.
The day and night cycle above is illustrative. It does not predict hourly radon concentrations in any building.
The radon story in text
Uranium occurs naturally in rock and soil. It decays into radium, and radium decays into radon, a colorless, odorless, tasteless radioactive gas. Radon moves through spaces in soil and can be drawn into buildings through pressure differences. It enters through cracks in foundations, floor-to-wall joints, gaps around pipes and utility penetrations, sump openings, construction joints, and crawl spaces. Indoors it mixes with the air people breathe in basements and living spaces. Concentrations change with weather, ventilation, and building conditions. Because radon cannot be sensed, measurement is the only way to know a building's concentration. All animation on this page is illustrative; radon is invisible.
Explore at your own pace
Open the cross-section
Prefer to click rather than scroll? Choose any point in the building or the ground beneath it.
Select a point
The whole picture
Radon starts in the ground, moves through soil, and can be drawn into the lowest levels of a building before mixing with indoor air. Choose a marker on the cross-section to read about that part of the path.
Illustration only. Radon is invisible and cannot be seen the way it is drawn here.
Why this matters
Why radon measurement matters
Long-term exposure to elevated indoor radon increases the risk of lung cancer. Measurement is how a property owner replaces guesswork with a number.
Health context
A known lung-cancer risk
The U.S. EPA and the World Health Organization identify radon as a leading cause of lung cancer, and EPA estimates about 21,000 radon-related lung cancer deaths each year in the United States. Risk rises with both concentration and years of exposure.
Typical concentrations
Indoor air differs from outdoor air
EPA gives the average indoor radon concentration in U.S. homes as about 1.3 pCi/L, compared with roughly 0.4 pCi/L outdoors. Individual buildings vary widely from these averages.
What changes the risk
Concentration × time
Exposure is cumulative, so the concentration and the number of hours spent in the building both matter. EPA also notes that radon exposure combined with smoking carries a greater risk than either alone.
This page summarizes public health guidance for general education. It is not medical advice and does not replace guidance from public-health agencies, a qualified radon professional, or a physician. Sources are listed under references.
Reading a result
What does your number mean?
Radon in air is reported in picocuries per liter (pCi/L). Move the control to see how published guidance describes a given concentration.
2.0
WHO 2.7
EPA 4.0
Drag the marker along the scale, use the slider, or type a measured result — the explanation below updates as you go.
3.2pCi/L
2.7 – 3.9 pCi/L
Below the EPA action level and above the WHO reference level. EPA suggests considering ways to reduce radon between 2.0 and 4.0 pCi/L. A qualified professional can discuss options.
This explainer restates published guidance for general education. It is not a diagnosis, a risk calculation for any individual, or a substitute for professional advice.
-
Below 2.0
A lower measured concentration. EPA notes there is no known level of radon exposure that carries no risk, so continue following appropriate retesting guidance.
-
2.0 – 3.9
EPA recommends that property owners consider taking action to reduce radon in this range. This band also spans the WHO reference level of 100 Bq/m³, about 2.7 pCi/L.
-
4.0 and above
EPA recommends taking action to reduce radon at or above 4.0 pCi/L (150 Bq/m³). EPA guidance also describes confirming an initial result before mitigating.
Risk does not begin suddenly at one threshold, and no result is described here as “safe.” A property’s level cannot be predicted from its age, neighborhood, appearance, or construction style — only from measurement.
A next step, if you want one
When you’re ready to explore reduction options
Radon Explorer focuses on independent radon measurement. Property owners who want to discuss mitigation options can learn more from Radon Removal, a New Jersey radon-mitigation specialist serving New Jersey and Staten Island.
External resource · opens in a new tab · Radon Explorer does not perform mitigation and makes no guarantee about work performed by others.
What we do
Professional radon measurement in New Jersey
One service, performed carefully, in the building types where people spend the most time.
Residential
Homes
Measurement for single-family houses, townhouses, condominiums, and residential transactions where applicable.
Multi-unit
Multifamily properties
Measurement planning for apartment buildings and other multifamily properties, including which units and locations to include.
Education & care
Schools and childcare
Professional measurement appropriate for occupied educational and childcare environments, coordinated around the daily schedule.
Commercial
Offices and workplaces
Radon measurement for offices and other workplace environments where staff spend regular hours.
Radon Explorer provides radon measurement only. We do not install mitigation systems and do not offer waterproofing, mold, duct cleaning, remediation, or home inspection services.
How measurement works
Four steps, start to result
-
Request an appointment
You submit the property information, preferred timing, and how you would like us to reply. Nothing is confirmed until you receive a response.
-
Confirm the measurement plan
Radon Explorer reviews the building type and measurement requirements, then confirms scope, timing, and price with you.
-
Measurement is performed
The measurement is carried out according to the confirmed plan and the requirements for the property.
-
Receive and understand the results
You receive the measurement results with an explanation of what the reported concentration means and what published guidance says about it.
About Radon Explorer
Measurement first. Clear information. Informed decisions.
Radon Explorer helps New Jersey property owners understand the radon concentrations in the buildings where people live, learn, and work. Our focus is professional measurement and clear reporting so clients can make informed decisions based on actual results.
Because we do not sell mitigation systems, our only product is the measurement itself and the explanation that comes with it.
Certified in New Jersey
Professional radon measurement statewide
- NJDEP radon certification number: MET15986
- Serving all 21 New Jersey counties
Radon Explorer focuses exclusively on measurement and clear reporting, helping clients make informed decisions based on actual results.
Questions
Frequently asked
What is radon?
Radon is a naturally occurring radioactive gas produced by the decay of uranium and radium in rock and soil. It has no color, smell, or taste, and it can accumulate indoors.
Why should a property be tested?
Because the concentration cannot be sensed or estimated from the outside. Testing is the only way to know whether indoor levels are low or elevated, and long-term exposure to elevated radon increases lung-cancer risk.
Can I tell whether a building has radon without testing?
No. Age, appearance, construction style, neighborhood, and even a neighbor’s result do not reliably predict a building’s concentration.
Do newer homes need radon measurement?
Yes. Newer construction can have elevated radon just as older construction can. Some newer buildings include radon-resistant features, but those features still need measurement to confirm the result.
Can two nearby houses have different radon levels?
Yes. Soil conditions, foundation type, openings in contact with the ground, and how a building is ventilated all differ between neighboring properties.
What does pCi/L mean?
Picocuries per liter — a measure of radioactive decay of radon per liter of air. EPA expresses its action level as 4.0 pCi/L; the WHO reference level of 100 Bq/m³ corresponds to roughly 2.7 pCi/L.
What happens during a measurement?
The measurement is set up in the agreed locations and completed according to the confirmed plan. We explain what to expect before the appointment.
How should a building be prepared?
Preparation depends on the reason for the measurement and the property. We confirm the instructions you need before the appointment.
Can occupants remain in the property?
We confirm any access or occupancy requirements for your property before the measurement begins.
How long does a measurement take?
The expected timing depends on the property and the reason for the measurement. We confirm it with the appointment details.
When should a property be retested?
Retesting guidance depends on the previous result, changes to the building, and the reason for the original test. We explain the applicable guidance along with your results.
What happens if the result is elevated?
We explain what the number means and what published guidance recommends. If you decide to pursue mitigation, you choose a qualified mitigation professional; we can point you to reduction resources, and we do not perform that work ourselves.
Does Radon Explorer install mitigation systems?
No. Radon Explorer specializes in radon measurement. It does not install mitigation systems.
Do you measure multifamily buildings?
Yes. We measure apartment buildings and other multifamily properties and will discuss which units and locations should be included.
Do you measure schools and childcare facilities?
Yes. We provide measurement for schools, kindergartens, and childcare facilities, scheduled around occupancy.
Do you measure offices?
Yes. We measure offices and other workplace environments.
Which parts of New Jersey do you serve?
Radon Explorer serves all 21 counties in New Jersey.
The one thing to do next
Know your number
Schedule a professional radon measurement for your New Jersey property. Submit the building details and choose text, email, or a phone call for our response.
Prefer to email directly? Write to book@radonexplorer.com.
After you submit
What happens after you submit?
Once your form is submitted, Radon Explorer will review the property details and respond using your selected communication method to confirm the measurement, scheduling, and next steps.
Text is the quickest option for many clients, while email and a phone call remain available when you choose them.
-
Send your request
Provide the property details and preferred timing.
-
We review the information
Radon Explorer confirms the property type and measurement requirements.
-
We contact you
You receive a response using the communication method you selected.
-
Confirm the appointment
Scheduling and any remaining details are finalized with you.
Service area: all 21 New Jersey counties · General information: business@radonexplorer.com · Booking: book@radonexplorer.com
Sources and references
Where the guidance on this page comes from
- EPA — What is EPA’s action level for radon and what does it mean?
- EPA — Health risk of radon
- EPA — Consumer’s Guide to Radon Reduction
- WHO — Radon and health
- NJDEP Radiation Protection Element — Radon
- New Jersey Radon Program (njradon.org)
New Jersey Radon Hotline: (800) 648-0394. Verify all values and recommendations against the current versions of these sources before publication; guidance is periodically updated.