What is Radon?

Radon is an invisible gas formed in the Earth’s crust. It surrounds every one of us as part of the air we breathe.

High levels over long periods of time are the issue. By monitoring radon long term, you can be alerted when levels are high and make small changes to improve the air you breathe.

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Looking for peace of mind about radon?

Airthings and AprilAire have teamed up to help

Everything you need to know about radon

Radon health issues: the facts

“Radon is the number 1 cause of lung cancer amongst non-smokers.”

In the air, radon breaks down into tiny radioactive elements (radon progeny) that can lodge in the lining of the lungs, where they can give off radiation. This radiation can damage lung cells and eventually lead to lung cancer.

As with most contaminants, the danger of radon arises from high levels or prolonged exposure over time. This is why continual monitoring is key to understanding your risk. Learn more about your radon levels here.

Causes of deaths in the USA per year according to the EPA

Radon / 21,000

Drunk Driving / 17,400

Falls in the home / 8,000

Drownings / 3,900

Home fires / 2,800

Where does radon come from?

The rocks and soil beneath our homes contain traces of uranium. Over time, the uranium breaks down and forms other elements. This is called radioactive decay. Radon is one element in the decay chain of uranium. When radon gas decays, it emits radiation in the form of an alpha particle. This radioactive particle is made up of two protons and two neutrons.

Radon, radioactivity and DNA

Radon progeny can attach to dust and other particles and can be inhaled into the lungs. As radon and radon progeny in the air break down, they give off radiation that can damage the DNA inside the body’s cells, says cancer.org.

All our cells contain DNA, which acts as an instruction manual or blueprint for cells on how to create copies of themselves. When an alpha particle hits our DNA it can cause damage to a cell’s blueprint. Cells constantly replicate themselves, but with a broken blueprint the replication process can become cancerous.


Radioactivity takes different forms including alpha, beta, gamma, and neutron radiation, which have different capabilities to penetrate different substances.

X-ray sources

Gamma radiation is just high-energetic electromagnetic radiation (photons). We can ‘artificially’ create such high-energy radiation in an X-ray tube, in that case we refer to it as X-rays. X-rays are commonly used in medical scans like those performed in a CT scanner.

Internal tissue

The radioactive daughter products of radon (mainly polonium isotopes) can be inhaled and become lodged in the lungs. When these radon daughters decay by emitting alpha particles, these will damage cells due to the close proximity between the decaying isotope and the DNA material. Alpha particles cannot penetrate deeply and are much less damaging if the radioactive material that emits the alpha particle is on the outside of the body (for example on the skin).

Radioactive radiation

Artificial sources

When we think of radiation, we often think of artificial sources, such as X-ray or medical scans, but these sources have little effect.

Alpha radiation vs Gamma radiation

Alpha radiation (such as radon) has a much greater effect on DNA than gamma radiation. Imagine DNA being hit by a cannonball, that is what alpha radiation is like. Whereas gamma radiation is like the DNA being hit by a needle. There is a big difference in damage.

Radon in my home

Modern buildings are often well insulated to save on energy bills. However, little airflow can allow radon to build up to high levels and cause long term exposure. Ventilation, which can be as simple as opening a window, is often the solution to keep radon levels safe. By long term monitoring, you can know when levels start to rise and act accordingly.

Is radon a man-made problem?

The radon concentration within buildings is often much greater than outside. The gas comes from the ground and is captured and contained in our homes, resulting in levels that we seldom find in nature.

How does radon enter my home?

Radon rises and can enter a home or workplace through cracks in the foundation, entry points for pipes and more.

Will radon reach the top floors?

Some buildings have a higher radon level in the top floors. This can be due to artificial ventilation, natural updraft, or building materials used.

Does the weather affect radon levels?

Yes. Radon levels can be affected by natural sources such as cold weather, wind, pressure and shifting soil—even earthquakes and local construction.


Radonmap.com uses Airthings sensors from around the world to show live radon levels, broken down by location and anonymized. See the yearly and monthly approximate risk calculations in this easy-to-use, interactive map! Your neighbour could have different levels of radon to you, so it’s important to monitor your own home.

Who is radon sensitive?

1 in 30 are fundamentally radon-sensitive.

All children are sensitive

Children’s organs are still developing

Their replicative tissue is more vulnerable to DNA damage.

Children weigh less

Their exposure is greater, as it is measured in concentration per kilogram.

Children breathe faster

They actually respire 2-3 times faster than adults as their lungs are much smaller.

Children have more life left

And thus could live long enough to get cancer from early life radon exposure.

“Radon is 10x more dangerous for children”

-Dr. Goodarzi presentation to Airthings 8th April 2019.

Why do radon levels change?

Radon levels change over time. That’s why it’s so important to measure continuously, to ensure your levels stay low.

The amount of radon emitted from the ground and the amount that actually enters our home can change due to the following reasons:





Building insulation

Your home’s foundation





Radon sampling: radon will not be distributed evenly around a room.

Imagine adding a dash of cream to a cup of black coffee but not stirring it. If you then take multiple samples from a small spot of that coffee for the level of cream, you would get very different readings over time as the cream slowly blends in with the coffee. Radon sampling works in the same way.

As a result, Airthings radon sensors give a short-term sample reading as well as an average long-term reading. This is why we recommend allowing your radon detector to measure for at least 30 days, so that the monitor can obtain enough air samples to provide a reliable long-term average.

What do my radon levels mean?


0 - 1.3 pCi/LNo action needed.

1.4 - 2.6 pCi/LExperiment with ventilation and sealing cracks to reduce levels.


2.7 - 4.0 pCi/LKeep measuring. If levels are maintained for more than 3 months, contact a professional radon mitigation. Check out our radon reduction tips here.


4.0 pCi/L and upKeep measuring. If levels are maintained for more than 1 month, contact a professional radon mitigation. Learn more about radon mitigation here.


  1. https://www.epa.gov/radon/health-risk-radon#:~:text=Radon%20is%20the%20number%20one,people%20who%20have%20never%20smoked
  2. https://www.epa.gov/radon/health-risk-radon#:~:text=Radon%20is%20the%20number%20one,people%20who%20have%20never%20smoked
  3. https://www2.dsa.no/en/radon
  4. http://multimedia.gsb.bund.de/BFS/BFS/Animation/radon/#Radon-Prognosen-und-Vorsorgegebiete
  5. https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/radiation/radon-another-reason-quit-fact-sheet-health-canada-2010.html
  6. https://www.who.int/news-room/fact-sheets/detail/radon-and-health
  7. https://www.cancer.org/cancer/cancer-causes/radiation-exposure/radon.html#:~:text=Being%20exposed%20to%20radon%20for,eventually%20lead%20to%20lung%20cancer
  8. https://www.epa.gov/radon/health-risk-radon
  9. https://www.epa.gov/radon/health-risk-radon
  10. https://www.cancer.org/cancer/cancer-causes/radiation-exposure/radon.html
  11. Dr. Goodarzi presentation to Airthings 8th April 2019
  12. Dr. Goodarzi presentation to Airthings 8th April 2019