Radon exposure: 3 things you need to know

Airthings, February 21, 2017

Am I exposed?

You might be aware of radon exposure if you work in the mining industry, live in an area with high concentrations of this gas or are about to sell your home and the government requires you to get a certified inspection. You may also remember radon from a time you saw it all the way to the right of the periodic table, on the noble gases section. Or maybe the name has come up in conversations, as more research is done and the name of this gas is more present in the media.Either way, if none of these situations are familiar to you, it’s still important to have a better understanding of what radon is, what it does, and know if you might be at risk of overexposure. This short article discusses three things you need to know about radon exposure.


Radon is a radioactive gas with no taste, smell or color. This means the human senses alone cannot detect it. That is why, although radon was discovered in 1899 and even back in 1530 Paracelsus noticed some health effects in miners, regulation and radon’s connection to lung cancer are fairly new. The knowledge about radon’s effect on health was so limited that there was a time in the 1970s where one could go to a uranium mine in the U.S. to receive radon radiation. It was advertising as a helpful relief to arthritis, sinus, and asthma. Luckily this information was proven false and the government banned this kind of advertisement in 1975. You can see an example of a newspaper ad on the left.

People understand working in enclosed areas where poisonous gases can gather is dangerous, but not all gases damage the lungs in the same way. Avoiding overexposure to radiation, and radioactive gases, can’t be solved with a miner’s canary. Your nose helps you to understand your surroundings. It helps you find the cause of normal situations, like knowing if a baby needs a diaper change or if something in your fridge has gone bad and you shouldn’t eat it. The harm in radon exposure, however, goes beyond air quality, what we can smell, and what our senses generally tell us about the safety of an environment. You can assume that very polluted cities or smoking lounges could be dangerous to your lungs, because you know you’re breathing contaminated air. You can see a cloud of smoke or haze from very far. You can also recognize the smell from quite a distance. In the case of radon, however, you don’t need to be underground, at a factory or in a smoking area to be at risk, and your senses will never be able to detect it. You could be sitting in your living room or at your office, and even have an air purifier and not notice that something’s wrong. Sadly, air purifiers “are incapable of stopping the tiniest particlesto which radon progeny adhere”.

In fact, people found out by chance that radon concentrates in homes and other enclosed areas. This happened in 1984 when a nuclear plant worker in the U.S. kept firing up the radioactivity alarms and they couldn’t figure out why. Here you can see what happened:



Thanks to that incident and the further work of scientists we now know radon exposure is harmful. But how or why?

How does radon exposure happen?

Radon is naturally present in nature. It comes from the core of the Earth, and it’s produced when another element, radium, decays. Because the planet has natural deposits of thorium and other more popularly known radioactive elements, like uranium, radon has been here for many centuries and it’s likely it’ll still be here for many more. What separates radon from other radioactive materials and makes it harmful, however, is that you might be inhaling too much of it, right now, without knowing about it.

According to the Toxicological Profile for Radon made by the Agency for Toxic Substances and Disease Registry from the U.S. Public Health Service, there are about 150 atoms of radon in each milliliter of air. Even though radon gas is very dense (about 8 times the density of our atmosphere), it doesn’t smell like anything, and it’s also not visible to the human eye. So, in a way, radon is everywhere on Earth, especially around areas with shale or granite. However, this doesn’t mean that we’re all at risk of getting lung cancer or other health complications derived from radon exposure.

It’s all about the quantity

Let’s discuss two examples to understand the harms of radon exposure: 

First example – We have night, day, and seasons because of the sun. Everyday the sun sends ultraviolet radiation although we cannot smell it, see it or hear it. We can feel it, however, as warmth. We even purposefully radiate ourselves to get a tan at the beach or a tanning salon, but we know we have to protect our skin to prevent sunburn or other complications. Without proper protection, too much ultraviolet radiation from the sun can produce skin cancer. The same happens with radon. Overexposure to radon gas can lead to lung cancer. Unfortunately, unlike skin cancer, there is no lotion or cream that prevents our noses from inhaling too much of this gas. Just like lying on the beach for 10 minutes will not give you skin cancer, inhaling radon at normal concentrations, like those that are normally present outdoors or in a well ventilated area, will not affect your lungs in a harmful way.


Second example – X-rays are another type of radiation which you might be familiar with. These powerful rays are “able to pass through solid matter, fog and photographic film”. Physicians normally used them to see broken bones or other irregularities not visible to the naked eye, like tumors or tuberculosis-infected lungs. We also know that overexposure to x-rays causes cancer thanks to scientist like Marie Curie, whose research helped us to have a better understanding of radiation and the protection we need against it. Once again, health complications depend on the amount of radiation you get. For example, when you go the doctor and get one x-ray to check your teeth or a broken bone, it’s very unlikely that radiation will significantly impact your health, as the amount of radiation is very little and the time of exposure is very short. Either way, you’ll still get a leaded apron to protect you while the radiologist takes the x-ray. But, unfortunately, just like it happens with ultraviolet radiation, there is no apron or mask that will protect you against inhaling radon.

So how much is too much?

The normal radon concentration outdoors is of about 10 Bq/m3. A well-ventilated room can reach those values. The U.S. Environmental Protection Agency (EPA) recommends radon levels at home below 148 Bq/m3. According to the WHO, “lung cancer risk rises 16 % per 100 Bq/m3 increase in radon exposure”. There are various factors involved in developing lung cancer because of radon overexposure, like how old you are, the length of the exposure, if you are a smoker or even the time of the year. For example, in places where winter is harsh and it’s unpleasant to regularly ventilate an area, radon can gather. There is more information about radon toxicity in a case study, which you can read here. When talking about lung cancer by itself, smokers are at a much higher risk that non-smokers. According to an articlepublished by the American Public Health Association, “[m]ore than 85 % of radon-induced lung cancer deaths are among smokers”. While quitting smoking will greatly reduce your chances of getting lung cancer, unfortunately, you are still at risk if you are overexposed to radon. As stated by the U.S. National Cancer institute, “it is estimated that more than 10 percent of radon-related cancer deaths occur among nonsmokers”. Keep in mind that we’re constantly receiving radiation in one form or another, but the amount and length of exposure is what matters. You may have been before in an area where radon concentration was very high, but it won’t affect you in the same way as having it in your bedroom or working space, where you normally spend around 8 hours.

So, what can you do now?

Yes, we know too much radon is bad. But how can we measure it? The simplest way to know how much radon there is around you is to test. There are digital radon detectors, radon test kits or even a professional who comes to your home to take measurements, a radon inspector. Each method has its own characteristics and devices are used differently. Home kits, for example, need to be sent to a lab after they have collected the information and need to remain static most of the time, for long periods of time. The accuracy of the readings can be affected by humidity and other types of radiation that are naturally present at home. These kits are cheap but may or may not be available in your area, as their certifications are country-based. Most of them are recommended only for tests within the United States.

In some countries it’s necessary to do a radon test before selling a property or building a new space. In this case, the help of a certified radon professional is required, as they need to issue a certified report. Just as the home kits, the availability of a radon inspector depends on where you live. Not all countries have radon inspectors or specific national regulations, regardless of the radon concentration of your country or the area where you live.

 Another solution is a digital radon detector, which gives you short and long term values that you can see at all times on the device’s screen or your phone, through its free mobile app. It’s also portable, which means you can use the same device to measure your office, your home or other indoor areas where you spend most of your time. You can compare the values shown on the digital radon detector with those approved by international organizations like the WHO, which makes these types of devices easier to use, as you (the user) don’t have to depend on a lab or a professional to tell you the radon levels around you. The device also measures the humidity and temperature around the space. Unlike test kits, these detectors don’t get affected by humidity or other radiation. Also, it can monitor the area for about one year and a half, with the same set of batteries. You can buy this device online and get it shipped to your country, which gives you greater flexibility if you’re in a place where the previous services are not available where you are. No matter which method you prefer to use, it’s important that you measure the radon levels around you to know if a mitigation system is necessary.


The WHO’s Radon & Health Fact Sheet tells us there are a couple of ways to reduce radon levels at home, such as:

“Increasing under-floor ventilation; installing a radon sump system in the basement or under a solid floor; avoiding the passage of radon from the basement into living rooms; sealing floors and walls; and improving the ventilation of the house”. Mitigations systems, like radon sump systems, could be expensive and require professional installation. Also, they’re not necessary in all cases, especially if radon levels are below 148 Bq/m3. Ventilating the area where you spend a lot of time is always a good solution, but it may not be completely effective if there’s something else directly affecting the level of radiation, like a crack on the ground. Once you know how much radon there is around you, it’ll be easier for you to see if nothing needs to change or if a mitigation method is required. Whatever the result, measuring the radon levels around you is the first and most important step to protect your lungs against radon exposure.

Do you have a problem? Click here for our top five tips to reduce radon. 

Our most popular products


Meet Corentium Home by Airthings, a simple to use, battery-operated radon gas detector with display.
Home $179.99


A smart radon detector with quick and accurate results on your smartphone.
Wave $199.99

Wave Plus

The first battery-operated smart indoor air quality monitor with Radon detection, including sensors for temperature, air pressure, humidity, VOCs, and CO2.
Wave Plus $229.99

Wave Mini

Now with mold risk indication! Wave Mini helps with asthma, allergies, sleep and overall health. The perfect first step to understanding health and comfort levels in any room.
Wave Mini $79.99


Complete the system. The Airthings Hub brings one or more devices online providing on-demand access to your indoor air quality (IAQ) data at anytime, from anywhere!
Hub $79.99


Meet Corentium Pro, a favorite of home inspectors and radon professionals. Fully AARST-NRPP certified for the North American market and beyond.
Pro $1299

Radon map

Thousands of Radon sensors across the world, broken down by location. See your region's approximate risk level.


Thousands of Radon sensors across the world, broken down by location. See your region's approximate risk level.