Radon in Your Home: The Invisible Risk You Cannot See, Smell or Taste

A home can look clean, smell fresh and feel completely normal—while an invisible radioactive gas slowly accumulates indoors.

That gas is radon.

Unlike smoke, natural gas or many other household hazards, radon gives you no obvious warning. It has no color, smell or taste, and exposure does not usually cause immediate symptoms. Testing and monitoring are the only practical ways to understand the radon level inside a building.

For homeowners with basements, lower-level bedrooms, below-grade offices or ground-contact living spaces, radon awareness should be part of a broader indoor air safety plan.

What Is Radon?

Radon is a naturally occurring radioactive gas created by the breakdown of uranium in rocks and soil. It can move from the ground into buildings and accumulate in enclosed indoor spaces.

Outdoors, radon usually disperses quickly and remains at relatively low concentrations. Indoors, however, it may become trapped—particularly in areas with limited ventilation or direct contact with the ground.

Radon may enter a building through:

• Cracks in concrete floors and foundation walls
• Gaps around pipes, cables and service openings
• Construction joints
• Floor drains and sumps
• Cavities inside walls
• Gaps around suspended floors
• Groundwater and certain building materials

Any building can potentially have elevated radon, including new or old homes, well-sealed or drafty properties, schools, offices and homes with or without basements.

Why Is Radon a Health Concern?

When radon decays, it produces radioactive particles. If inhaled, these particles can settle in the airways, where they may damage the DNA of lung cells over time. Long-term exposure increases the risk of lung cancer.

The World Health Organization estimates that radon may account for approximately 3% to 14% of lung cancers in a country, depending on average radon concentrations and smoking prevalence. WHO also reports that lung-cancer risk increases by approximately 16% for every 100 Bq/m³ increase in the long-term average radon concentration.

The U.S. Environmental Protection Agency estimates that indoor radon contributes to approximately 21,000 lung-cancer deaths each year in the United States. The combined risk from smoking and radon exposure is substantially higher than either risk alone.

Radon does not normally cause headaches, coughing, dizziness or other immediate warning symptoms. Health effects generally develop only after years of exposure, which is why waiting for physical symptoms is not an effective safety strategy.

Why Are Basements and Lower-Level Rooms Important?

Radon typically enters a building from the soil beneath or around its foundation. This means concentrations are often highest in basements, cellars and rooms that directly contact the ground. However, elevated radon can also be found on upper floors, and levels may differ considerably between neighboring homes.

Lower-level spaces deserve special attention when they are used as:

• Bedrooms
• Family rooms
• Home offices
• Playrooms
• Home gyms
• Guest rooms
• Workshops
• Long-term storage or hobby areas

EPA guidance recommends testing in the lowest level of the home that could be occupied regularly, such as a finished basement, lower-level bedroom, family room or office.

A basement that was once used only for storage may become more important after renovation. When a family begins using a lower level as a bedroom, office or living area, the EPA recommends retesting that level.

Radon Levels Can Change Over Time

Radon is not necessarily constant throughout the day or throughout the year.

Indoor concentrations can be affected by:

• Weather conditions
• Seasonal temperature changes
• Atmospheric pressure
• Ventilation habits
• Heating and cooling systems
• Window and door use
• Foundation conditions
• Building renovations
• Radon-mitigation system performance

WHO notes that radon levels can vary significantly from hour to hour, day to day and between seasons. Because of this variability, longer measurement periods provide a better understanding of average exposure than a single isolated reading.

A short test can provide a useful snapshot. Ongoing monitoring can provide something different: visibility into how the level changes over time.

One-Time Testing and Ongoing Monitoring Serve Different Purposes

A professional test or approved passive test kit may be required for real-estate transactions, regulatory compliance or official mitigation decisions.

An ongoing electronic monitor is useful for:

• Watching long-term trends
• Comparing seasonal changes
• Checking lower-level rooms regularly
• Observing the effect of ventilation changes
• Checking whether levels remain low after mitigation
• Receiving alerts when readings cross a selected threshold
• Identifying unexpected changes after renovation or building work

The two approaches should complement each other rather than compete.

A smart monitor can help homeowners stay aware between professional tests, but it should not replace testing required by local law, building regulations, workplace requirements or real-estate procedures.

What Radon Level Requires Attention?

Radon reference and action levels vary by country and local jurisdiction.

In the United States, the EPA recommends taking action when the radon level reaches 4 pCi/L, approximately 150 Bq/m³, or higher. It also recommends considering mitigation when levels are between 2 and 4 pCi/L because no radon exposure level is considered completely risk-free.

WHO recommends that countries establish a residential reference level of 100 Bq/m³ where possible. If that level cannot be achieved under local conditions, the national reference level should not exceed 300 Bq/m³.

Always interpret readings according to the guidance of the country, state or local authority where the property is located.

What Should You Do If Radon Is Elevated?

Do not panic over a single short-term reading. Radon concentrations naturally fluctuate, and important decisions should generally be based on appropriate averages and confirmation testing.

Recommended next steps may include:

1. Confirm the result

   Follow the testing procedure recommended by your local authority. This may involve a second short-term test, a long-term test or professional measurement.

2. Contact a qualified radon professional

   A certified or locally recognized specialist can assess the building and recommend an appropriate mitigation approach.

3. Consider a radon-reduction system

   Common mitigation strategies include sub-slab or soil-depressurization systems, improved under-floor ventilation, sealing significant entry routes and other building-specific measures. EPA generally favors methods that prevent radon from entering the building.

4. Continue monitoring after mitigation

   Mitigation equipment requires occasional inspection and maintenance. The EPA recommends retesting periodically to confirm that levels remain low.

Professional radon-reduction systems can be highly effective, with some systems reducing indoor levels by as much as 99%, depending on the building and selected method.

Introducing FABISENSE RadonSense Pro

FABISENSE RadonSense Pro is a smart plug-in and portable radon monitor designed to provide ongoing radon visibility in basements and lower-level living spaces.

Instead of showing only one isolated test result, RadonSense Pro helps users observe how radon changes across different time periods.

It is designed for spaces such as:

• Basements
• Lower-level bedrooms
• Below-grade offices
• Family rooms
• Home gyms
• Ground-contact living spaces
• Homes with existing radon-mitigation systems

RadonSense Pro uses an alpha-spectrometry monitoring system with a passive diffusion chamber. Initial readings begin within approximately 30 minutes after powering on, while longer trend periods help users build a more meaningful picture of changing conditions.

See More Than a Single Number

RadonSense Pro provides several trend windows:

• 3-hour trend
• 24-hour trend
• 7-day trend
• 30-day trend

The monitor supports both common radon units:

• pCi/L — picocuries per liter
• Bq/m³ — becquerels per cubic meter

Its color status display uses green, yellow and red indicators to make the current condition easier to understand at a glance.

A single short-term reading can change quickly. Trend information helps place that number into context.

Connected Monitoring with Tuya Smart and Smart Life

RadonSense Pro supports the Tuya Smart and Smart Life app ecosystem.

Through the app, users can access:

• Current radon readings
• Historical trends
• Alarm history
• Monitoring reports
• App push notifications
• User-adjustable alert thresholds

The monitor also provides local sound and light alerts, so users do not have to rely only on their phone.

This connected approach can be especially useful when the monitor is installed in a basement, lower-level office or another room that is not visited frequently throughout the day.

Where Should You Place a Radon Monitor?

For a representative measurement, place the monitor in the lowest regularly occupied level of the home.

Choose a location such as:

• A basement family room
• Lower-level bedroom
• Home office
• Playroom
• Den
• Frequently used lower-level space

Avoid locations affected by:

• Direct drafts from windows or doors
• Heating or air-conditioning vents
• Fans
• Direct sunlight
• Fireplaces or strong heat sources
• High humidity
• Cooking steam
• Bathrooms or laundry areas

Official EPA testing guidance recommends using a regularly occupied room on the lowest appropriate level and keeping the device away from drafts, excessive heat and high humidity.

Always follow the placement instructions included with the monitor.

Why Ongoing Radon Awareness Matters

Radon is easy to ignore because there is nothing to see or smell.

But that invisibility is exactly why testing and monitoring matter.

Ongoing monitoring can help answer questions such as:

• Are levels higher during winter?
• Does ventilation reduce the reading?
• Did levels change after a renovation?
• Is a mitigation system continuing to work?
• Is the basement different from the first floor?
• Are short-term spikes becoming a longer-term pattern?

The goal is not to create anxiety around every temporary change. The goal is to replace uncertainty with useful information.

Important Safety Note

RadonSense Pro is designed for ongoing home radon visibility and trend monitoring.

It is not a replacement for:

• Professional radon testing
• Testing required during real-estate transactions
• Legally mandated workplace testing
• Qualified radon-mitigation services
• Guidance from local health or radiation authorities

When a reading is elevated or remains elevated, follow local testing protocols and contact a qualified radon professional.

The Bottom Line

Radon can enter almost any building. You cannot see it, smell it or determine its concentration based on the age, appearance or location of a home.

Testing is the only way to know whether radon is present at an elevated level. Ongoing monitoring adds another layer of visibility by showing how conditions change over time.

FABISENSE RadonSense Pro helps make an invisible indoor risk easier to understand—through connected monitoring, trend tracking and practical alerts for the spaces closest to the ground.

Know the level. Watch the trend. Protect your home.

Discover FABISENSE RadonSense Pro

Frequently Asked Questions

Can you smell or see radon?

No. Radon has no smell, color or taste. A measurement device is required to determine the concentration inside a building.

Does every home need radon testing?

The EPA recommends testing all homes because elevated radon cannot be predicted reliably from appearance, building age or a regional map. Neighboring homes can have very different results.

Is radon only a basement problem?

No. Levels are often higher in basements and ground-contact rooms, but radon can also be present on upper floors. The lowest regularly occupied level is generally the most important place to begin testing.

Does RadonSense Pro replace professional testing?

No. It is designed for ongoing home visibility and trend tracking. Professional or approved testing may still be required for mitigation decisions, legal compliance or real-estate transactions.

How quickly does RadonSense Pro provide a reading?

Initial readings begin within approximately 30 minutes after the monitor is powered on. Because radon fluctuates, longer averages and trend data are more useful for understanding ongoing conditions.

Can I check RadonSense Pro from my phone?

Yes. It supports Tuya Smart and Smart Life app access for current readings, historical trends, reports, alarm history and push notifications.