Quick Answer

Radon is a naturally occurring radioactive gas that can build up inside homes without any visible warning signs. Because it is colorless, odorless, and impossible to detect without testing, the only reliable way to screen your home for radon is through testing. Homeowners can check radon levels using short-term test kits or continuous digital radon monitors that track changes over time.

According to the U.S. Environmental Protection Agency (EPA), radon has been found in homes across all 50 states, regardless of age, size, or construction type. 

What Makes Radon a Hidden Threat?   

Most household problems come with a warning sign. Water leaks leave stains. Mold creates odors. Electrical issues may spark or flicker.

Radon, on the other hand, forms naturally as uranium breaks down in soil and rock beneath the ground. From there, the gas can move upward through cracks in foundations, construction joints, sump pits, crawl spaces, and openings around pipes before becoming trapped indoors.

What makes radon especially concerning is that homeowners cannot see, smell, or taste it.

Many people assume radon is only a concern for older homes or certain regions, but elevated levels have been detected in both new and existing homes throughout the United States. The EPA’s radon guide estimates that nearly 1 in 15 homes in the U.S. has elevated indoor radon levels. According to Health Canada, 18% of Canadian homes have radon levels at or above the national action guideline of 200 Bq/m3.

The important thing to remember is that radon-related risks are preventable once you know your levels.

That is why regular radon testing at home is considered one of the most important indoor air quality checks homeowners can perform.

Are There Signs of Radon in Your Home?

This is one of the most common questions homeowners ask.

Unfortunately, there are no physical signs of radon in your home that you can detect without testing. Radon does not create immediate symptoms, unusual smells, or visible damage inside a property.

That is part of what makes it difficult to identify early.

Long-term exposure to elevated radon levels has been linked to lung cancer, but the effects typically develop gradually over many years. Because of this, radon testing remains the only reliable way to determine whether elevated radon is present in your home

No home can be considered “safe from radon” without an actual measurement.

Why Radon Testing Matters More Than Ever

Indoor air quality has become an increasingly important topic for homeowners, especially as people spend more time at home working, sleeping, and living.

Radon testing helps homeowners:

• Better understand the air quality inside their unique homes rather than relying on assumptions or regional averages

• Identify elevated radon levels early before long-term exposure becomes a health concern

• Monitor radon changes over time since radon levels naturally fluctuate with weather, seasons, ventilation, and home usage

• Make informed decisions about radon mitigation or continued monitoring if levels rise

• Gain peace of mind by understanding whether their indoor environment falls within recommended safety ranges

Many homeowners are surprised to learn that radon can vary significantly even between neighboring homes. Two houses on the same street may produce completely different readings depending on soil conditions, foundation type, airflow, and structural design.

That is why experts recommend testing every home individually rather than relying on local assumptions.

How to Test for Radon: Do-It-Yourself Approach  

Homeowners today have several reliable ways to screen their homes for elevated radon levels. The right option often depends on whether you need a quick snapshot or long-term monitoring.

Short-Term Radon Test Kits

Short-term radon test kits are one of the most accessible starting points for homeowners.

These kits are commonly available online and in hardware stores, typically costing under $30. Most use charcoal canisters to absorb radon over a 48–96 hour testing period. After the test is complete, the kit is mailed to a laboratory for analysis.

Short-term kits are useful for initial screening and can help identify whether further testing is needed.

However, there is an important limitation.

Radon levels fluctuate constantly throughout the day and across seasons. Weather conditions, rainfall, ventilation habits, and HVAC usage can all influence indoor readings. A short-term test captures only a brief window of activity rather than a full, long-term picture.

The EPA considers short-term tests a screening tool rather than a definitive long-term measurement.

Continuous Digital Radon Monitors

Continuous radon monitors provide a much more complete understanding of indoor radon exposure.

Instead of collecting a single snapshot, these monitors measure radon continuously throughout the day and night. Many modern devices update their readings every 10 minutes, allowing homeowners to track long-term trends.

This type of monitoring is especially valuable because radon levels naturally rise and fall due to:

• Seasonal weather changes

• Rainfall and soil moisture

• Ventilation habits

• HVAC system usage

• Window and door activity

• Air pressure differences inside the home

Continuous monitoring helps homeowners see patterns that short-term kits miss, including common overnight elevations and seasonal fluctuations.

Many smart radon monitors now connect directly to mobile apps, making it easier to receive alerts, review trend data, and monitor indoor air conditions in real time.

Short-Term Kits vs Continuous Radon Monitors 

Both methods can be useful, but continuous monitoring provides a broader understanding of how radon behaves inside a home over time. 

Where to Place a Radon Test for Accurate Results

Proper test placement plays a major role in obtaining accurate readings.

The EPA recommends placing radon tests in the lowest livable level of the home. This could include:

• A finished basement

• A ground-floor family room

• A regularly used lower-level bedroom

• A home office or living space near the foundation

For best accuracy:

• Place the device at least 20 inches above the floor

• Keep it away from windows, vents, and exterior doors

• Avoid kitchens, bathrooms, and high-humidity spaces

• Keep short-term test conditions closed during the testing period

Closed-house conditions help reduce airflow changes that could interfere with short-term measurements.

Understanding Your Radon Test Results

Radon gas is measured differently depending on where you live. In the United States, radon is measured in picocuries per liter (pCi/L), while in Canada and Europe, it is measured in Becquerels per cubic meter (Bq/m³). Both units measure the concentration of radioactive radon particles in indoor air.

While guidelines vary by country and organization, health authorities agree on one important point: higher radon levels increase health risk, and lower levels are always better.

• Below 2 pCi/L (74 Bq/m³)
  Considered relatively low risk. However, because radon levels naturally fluctuate over time, periodic or continuous monitoring is still recommended, especially in areas known for elevated radon.

• Between 2 and 4 pCi/L (74–148 Bq/m³)
  The EPA encourages homeowners to consider additional monitoring and mitigation planning. Although below the U.S. action level, long-term exposure may still present a risk.

• 100 Bq/m³ (2.7 pCi/L) or Higher
  The World Health Organization recommends a lower reference level of 100 Bq/m³ where possible, to better reduce long-term health risks.
• 4 pCi/L or Higher (148 Bq/m³+)
  The United States Environmental Protection Agency recommends taking corrective action and consulting a certified radon mitigation professional.

• 200 Bq/m³ (5.4 pCi/L) or Higher
  Health Canada recommends taking action if indoor radon levels exceed 200 Bq/m³, which is Canada's official radon guideline.

Pro Tip: Radon levels naturally fluctuate throughout the day, across seasons, and even between rooms in the same home. A single test provides only a snapshot in time, which is why continuous monitoring can help homeowners better understand long-term exposure and how their home responds to ventilation, weather, and seasonal changes.

Most mitigation systems use sub-slab depressurization, a method designed to safely redirect radon gas away from the home before it enters indoor living spaces.

According to the EPA Radon Mitigation Standards, properly installed mitigation systems can significantly reduce indoor radon levels in most homes.

A Smarter Way to Monitor Radon at Home

As awareness around indoor air quality grows, many homeowners are moving beyond one-time test kits and choosing continuous radon monitoring solutions instead.

Ecosense develops professional-grade radon monitors designed to make ongoing monitoring more accessible, responsive, and easy to use.

Its technology uses patented ion chamber detection methods similar to those used by certified radon professionals.

EcoQube

• Wi-Fi-connected smart radon monitor

• Real-time mobile app tracking

• Hourly trend charts and alerts

• Includes a free EPA-aligned 72-hour test

• Named one of TIME’s Best Inventions of 2021

EcoQube Flex

• Battery-powered and portable

• Useful for testing multiple rooms or floors

• Designed for flexible home monitoring

• Nominated for the 2026 Edison Awards

EcoBlu

• Plug-and-play setup

• Readings displayed directly on the device

• Updates every 10 minutes

RadonEye

• Bluetooth-connected monitoring

• OLED display with professional-grade accuracy

• Designed for real-time radon tracking

All Ecosense radon monitoring devices provide an initial reading within as little as 10 minutes and achieve high accuracy within the first 10 hours of monitoring.

Final Thoughts

Because radon cannot be detected through sight, smell, or immediate physical symptoms, testing remains the only reliable way to understand whether elevated levels are present inside a home.

The good news is that screening your home for radon is now easier and more accessible than ever. Whether you choose a short-term test kit or a continuous digital monitor, taking the time to measure radon levels can help you make more informed decisions about indoor air quality and long-term home safety.

For homeowners looking to better understand their indoor environment, continuous radon monitoring is the simplest and most valuable step toward creating a healthier living space.

FAQs:

Q1: How do I know if I have a radon problem without testing?

Radon cannot be detected without testing because it is colorless, odorless, and invisible. There are no physical signs of radon in your home that can reliably indicate elevated levels. Testing is the only way to know whether radon is present indoors.

Q2: Can I do radon testing at home myself, or do I need a professional?

Yes, many homeowners successfully perform radon testing themselves using short-term test kits or continuous digital radon monitors. For real estate transactions, mitigation verification, or official inspections, a certified radon professional may also be recommended.

Q3: What are the health risks of long-term radon exposure?

Long-term exposure to elevated radon levels increases the risk of lung cancer over time. According to the EPA, radon is the leading cause of lung cancer in the United States among non-smokers. Risk levels increase with prolonged exposure and higher concentrations.

Q4: How often should I check radon levels in my house?

The EPA recommends testing your home every two years under normal conditions and after major renovations, basement finishing projects, or ventilation changes. Continuous radon monitors help tracking fluctuations year-round rather than relying on occasional testing alone.

Q5: What is the most accurate way to monitor radon at home?

Continuous digital radon monitors provide one of the fastest and most accurate ways for homeowners to track indoor radon levels over time. Unlike passive test kits that require laboratory processing, Ecosense smart radon monitors deliver real-time readings and ongoing trend analysis for better long-term visibility.