Radon: awareness in 2024 remains low despite rising levels

Understanding radon gas and its risks

Radon is an invisible and radioactive gas that poses an increasing threat to health worldwide. As buildings become more energy-efficient and airtight, radon levels in our homes, workplaces, and schools are rising.

Despite being the second leading cause of lung cancer, recent surveys show that most people are unfamiliar with radon and its dangers. This article reviews the current state of radon levels globally, using Airthings' insights and recent research, revealing concerning trends in homes, schools, and commercial buildings⁠.

What is radon gas?

Radon is an odorless, colorless, and tasteless radioactive gas. It forms when uranium, a naturally occurring element in soil, rock, and water, breaks down and releases gas. Radon occurs naturally and is found everywhere in the world. Outdoors, radon disperses harmlessly. Indoors, however, it can accumulate to dangerous levels, especially inside modern, well-insulated buildings with limited ventilation. 

Why is radon dangerous to health?

Prolonged exposure to high radon concentrations can make people very sick. Exposure increases the risk of inhaling radioactive particles, which can lodge deep in our lungs and cause genetic mutations in our bodies, potentially leading to lung cancer. The only way to know if radon is present is to monitor for it. 

Radon is everywhere, not just in the home

Radon isn’t limited to people’s homes. Schools, workplaces, and commercial buildings are also at risk. For example, the EPA estimates that 19.3% of U.S. schools, nearly 1 in 5, have at least 1 frequently occupied ground contact room with short-term radon levels above 4 pCi/L (148 Bq/m3). The level at which EPA recommends mitigation. In total, EPA estimates that over 70,000 schoolrooms in use today have short-term radon levels above 4 pCi/L. 

Building age doesn't matter, radon gas can find its way into older and newer buildings and build up without adequate ventilation.

Global radon trends

Radon in Canada: concerning rises

Recent studies, such as the 2024 Cross-Canada Survey of Radon, highlight that radon is rising worldwide.

The Cross-Canada survey saw researchers analyze residential radon gas exposure, estimating the proportion of Canadians living in homes exceeding the Canadian guideline of 200 Bq/m³ and the WHO (World Health Organization)’s 100 Bq/m³ threshold. 

Canada's geology and climate are one of the main reasons for its high concentrations of radon.

The report made some startling findings: 

• Nearly 1 in 5 (17.8%) Canadian houses measures radon at 200 Bq/m3 or above
• An additional 24.2% of people reside in houses with radon levels between 100-199 Bq/m³ 
• Overall, 83.6% (245/293) of Canada’s current Census Divisions had at least 1 house whose radon level was at or above 200 Bq/m³
• No areas of Canada are totally radon-free.

These findings have significantly increased from a similar Canadian study conducted in the late 2000s when only 6.9% of houses were at or above 200 Bq/m³. 

Norway: another high radon region

Norway, also home to Airthings, faces unique radon gas challenges due to its climate and geology.

Findings from Airthings’ data

Global data, local insights

Airthings aggregates anonymized data from thousands of sensors worldwide. 2024 radon data reveals:

• Rising radon levels: Our analyses align with large-scale studies such as the 2024 Cross-Canada Survey of Radon, confirming that radon levels are increasing worldwide.
• Global coverage, local insights: Certain regions, like Utah in the U.S. or parts of Canada, consistently show higher radon concentrations. However, elevated levels can appear anywhere due to seasonality and local (i.e. building practices) conditions.
• Seasonal & building-specific trends: Continuous measurements show that radon often spikes in winter and during periods of low ventilation. Commercial buildings see radon rise when ventilation systems are off, such as overnight and at weekends.

Testing for radon means safer levels

For example, Airthings’ indoor air quality (IAQ) data shows that once people start monitoring their homes and identify they have radon, they effectively mitigate. 

The graph below shows radon data from 200 Airthings IAQ monitors located in basements across Norway. The red line shows radon levels captured across 200 consecutive weeks (just under 4 years). As demonstrated, there is a downward trend in levels, going from around 200Bq/m³ at the start of 2023, to around 100Bq/m³ towards the end of 2024.

The graph above shows 200 weeks' worth of Airthings' data collected from 200 monitors in basements across Norway

Airthings data summary:

• Between week 2 and week 54, devices show a radon reduction from 201 Bq/m3 to 141 Bq/m3 -> 30% reduction
• Between week 12 to week 64, devices show a reduction from 160 Bq/m3 to 118 Bq/m3 -> 27% reduction

Norwegian case studies: radon testing at school and at home

Airthings works with over 100 of Norway’s municipalities, helping schools and public buildings identify when radon exceeds safe limits and adjust ventilation to reduce levels, improving safety without major expenses.

Radon in schools

Sunndal Municipality:

• Initial findings: Airthings devices revealed radon levels were regularly above Norway’s recommended annual average of 200 Bq/m³
• Mitigation efforts: Adjusting ventilation systems effectively reduced radon levels without installing any formal mitigation systems
• Ongoing monitoring: Continuous data from Airthings devices helps Sunndal monitor that mitigation is successful and radon stays within safe limits
  

Radon at work

Stats Vegvesen (Norwegian Highway Authority)

• Challenge: The Bergen office of Norway’s highway authority, “Statens vegvesen” needed an effective indoor air quality monitoring solution that measure radon and other IAQ parameters 24/7
• Solution: Airthings’ partner, Energy Control, installed Airthings devices to provide live data on radon and other air quality metrics.
• Outcome: Monitoring helps prove the impact of ventilation systems and energy-saving measures, showing when radon levels rise or fall based on building usage and airflow adjustments
• Looking ahead: Live data offers peace of mind and alerts when action is needed to reduce radon, while optimizing ventilation, and ensuring a safe and healthy indoor environment

Airthings data insights: monitoring optimizes indoor air quality and safety

Airthings indoor air quality data reveals a clear pattern: radon levels stay low during office hours when ventilation runs but then increase on weekends when ventilation is off. Radon may indeed rise at night and over the weekend. However, continuous data from Airthings devices helps to guide facility managers in optimizing their building’s ventilation schedules when in use, and balance occupant health and comfort with energy efficiency to protect occupants from harm to their health. 

Airthings 2024 survey reveals over half remain unaware of radon and its health risks

In December 2024, we asked 1,120 US-based respondents about their general awareness of radon. The results are, we feel, concerning and reveal that awareness and action on radon remains low. 

In summary:

• 70% are either unfamiliar or only vaguely familiar with radon gas
• 69% have never tested their home for radon gas
• Humidity was of more concern than radon with regards to specific air quality worries
• 76% are unaware of any free radon-testing services in their region
• 74% are unaware about any state regulations or recommendations about radon levels

These results highlight a need for increased awareness and public education around radon and why it is so dangerous. 

The conclusion? Monitor and mitigate radon 

Radon is a silent but serious threat. As Airthings data, alongside other research shows, radon is rising worldwide. The good news? Radon monitoring and testing empowers people to take control of their indoor air quality. Airthings’ always-on digital monitors help people to detect, mitigate and keep radon gas at a safe and healthy level; whether at home, work, or school. 

Looking ahead, Airthings will continue to collect and analyze radon data and turn these insights into action. The company’s mission is to educate people and raise awareness that radon is silent and potentially deadly to our health.

Smarter Airthings digital radon detector coming in 2025

Monitoring levels over time is the only way to know if you have a radon problem. In response to the growing demand for radon monitoring and other indoor air quality products, Airthings will launch Corentium Home 2 later in 2025. This device will be a smarter version of the original award-winning Corentium Home; the most trusted digital radon detector in the world. Updated features include real-time radon monitoring, connectivity to the Airthings app, and improved sensor technology.

Take action against radon today and protect you and your loved ones. Join Airthings’ global movement for healthier indoor air that’s safe from radon, whether at home, at work, or at school.