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Home Radon Detector Kits
Continuous radon monitors are more accurate, but a short term radon test kit is inexpensive and gives you quick results. Scroll to the bottom to learn how to choose the best radon detector for your home.
Aranet makes a portable radon monitor that’s ideal if you’re renting, move frequently, or just enjoy a super long battery life — it lasts up to 7 years, or up to 4, if you use the bluetooth connectivity to connect readings to your phone. You can view long term data trends in the app. It also takes temperature and humidity readings and is super accurate, developed by a team of radio engineers. Uniquely, Aranet also has an Ionizing Radiation Detector here, which measures your daily in-home exposure to gamma, beta, and x-rays. Both models are also available through Amazon here.
Airthings makes a less expensive, no-frills, battery-powered radon detector that doesn’t report readings to an app, though you can request a print out a report if you want to see long term data trends. Otherwise, it’s a simple, straightforward, and accurate choice. Use code interiormed-10OFF for 10% off directly through the Airthings site here. Also available on Amazon here.
Most Accurate Radon Detectors
This model is the best radon detector for basements because it also tracks humidity and temperature, which can help you prevent mold. This radon detector with WiFi mounts permanently on a wall and reports radon levels and the other indoor air quality metrics directly to your phone through the app. It’s also RESET certified, so you know it’s accurate. You can always get this along with a short term kit for both immediate answers as well as long term, more accurate answers. Use code interiormed-10OFF for 10% off directly through the Airthings site here. Also available on Amazon here.
Airthings View Plus
This is the best radon detector for homes because it measures levels year round, making it much more accurate than the 4 day short term tests. Radon fluctuates a lot over seasons and years, so short term tests can miss high readings, giving a false sense of security, or on the flipside, give you the one high reading of the year, when your average is actually very low. This digital radon detector also monitors VOCs, PM 2.5, CO2, humidity and temperature. I use it in my own house and love it. It’s RESET certified, so this is one of the most accurate radon detectors available for your home. Use code interiormed-10OFF for 10% off directly through the Airthings site here. Also available on Amazon here.
Faster Radon Test Kits
If you aren’t interested in year-round monitoring, this long-term radon test is easy to set up, and takes measurements for 90 days. It is much more accurate than a short-term radon detection kit, and is the second-most inexpensive option. Well rated and reasonably priced, lab analysis is included. You can get this along with a short term kit for both immediate answers and more accurate answers. If you’re worried about radon coming from your granite countertop, you could consider getting two of these— use one to take a baseline/general reading in your basement or lowest floor, and place the second one on your countertop. While this isn’t a scientifically validated method according to the EPA, it is possible that it might work and give you some peace of mind.
4 Day Short Term Radon Test Kit
This is the best radon test if you’re looking for a fast, inexpensive screening option and aren’t as worried about long-term accuracy. Short-term tests are used over 4 days, and even though a 2019 study from Canada found that a whopping 99% of short-term tests are inaccurate (because radon levels fluctuate day-to-day, and over the years) it’s still definitely worth doing a quick test just to see if levels are high. If they are, pursue radon mitigation. If they’re low, great! But, it’s a good idea to do a 90 day or continuous test to make sure you didn’t just capture a low radon day.
Water Radon Test Kit
Radon makes its way into the water supply and not all cities test for it— it’s not federally required! Outside of city water supplies, it’s super important to test for radon in your water if it comes from a groundwater source, like a private or shared well, or if you have a known issue with airborne radon. Simple Lab wins awards all the time for its user friendliness— the kit includes easy instructions and sampling materials, prepaid 2 day shipping, lab testing, and you get the results reported digitally.
More Healthy Design for You
Radon Basics
What is radon?
Radon is a radioactive gas, and is continually released by the bedrock that lies under the foundations of 7 million homes in the US. Uranium is a natural part of soil, granite, and bedrock, and as it decays it turns into radon gas and is released up into the air. As radon gas rises, it can enter buildings through small cracks and become trapped in high concentrations in the basements and first floors of homes. Radon can also dissolve into groundwater instead of into the air, and can be released through tap water in the form of steam inside your home while showering, doing the dishes, or the laundry. The fix is easy— a radon release tube or radon-resistant ground covering. But, you have to test your home to know it’s there.
How much radon is too much?
The official guidance by the EPA is to strongly consider having radon mitigation done if your readings are between 2-4pCi/L, and to definitely have it done if levels are above 4pCi/L.
What radon levels are safe?
Technically, there is no known safe level of radon— however, a super low amount is a normal part of life and humans have been exposed to it, even outdoors, for all time. As it escapes from the rocks that make up the earth, outdoor levels hover around 0.4pCi/L. In Ikaria, the Greek Island known as a “Blue Zone” for longevity, outdoor levels actually hover a little higher than average. So, while truly high levels are definitely associated with cancer, it’s not worth stressing out about very low, normal levels. The body is equipped to handle a normal amount of radiation (and may even benefit from this type of limited stress.) The issue is when radon gets trapped in buildings and we spend lots of time indoors exposed to too much of it. Radon is a little like the sun in this way — some is good, and we need both vitamin D and circadian rhythm setting, but too many UV rays, and we can get sunburns, or even skin cancer.
The average home has a level of 1.3pCi/L, and the EPA recommends considering having radon mitigation done if your readings are between 2-4pCi/L— and to definitely have it done if levels are above 4pCi/L (that’s 10 times higher than outdoor, background levels.)
Why is radon becoming a more common problem?
As homes are being built with more square footage, and therefore more ground coverage over Radon-containing rock, Radon is becoming an increasingly common problem. And, with the tightly-sealed nature of energy-efficient, climate-controlled homes, Radon has less chance to escape.
Radon and Your Health
Why is radon dangerous?
Radon is the second most common cause of lung cancer, causing 21,000 deaths per year in the United States. There is increasing evidence it is associated with increased risk of childhood leukemia, as well. Finally, some epidemiological evidence shows that exposure during pregnancy is associated with cleft lip and palate in the baby.
Can radon make you sick?
Yes, over the long term, it can cause cancer. But in the short term, radon doesn’t cause any health effects. Even though radon eventually leads to lung cancer, it doesn’t cause coughing or pain immediately when there are high levels in your home.
Can radon cause headaches?
No, radon doesn’t cause headaches, or any other acute health effects. It takes years of breathing in radon to damage your lungs.
Radon Map
Can I look up my radon risk by zip code?
Yes. This map comes from the EPA and shows your risk by county. Zone 1, in red, is the highest risk. Zone 2, orange, is associated with medium risk, and Zone 3 is associated with lower risk. That said, radon has been detected in all states, and even if you live in Zone 3 it is worth testing.
You can also use this link to type in your county name and it will tell you if it’s Zone 1, 2, or 3.
Where Radon Comes From
Where is radon found?
The most common source of radon is granite and other types of stone (limestone, shale) in the bedrock under homes. This map of the United States shows the radon risk for your zip code, based on the type of rock underlying your neighborhood, and the radon incidence in homes near you.
The most common place for it to be found is in the lowest level of your house, typically the basement. Some does rise to floors above the basement, as well.
Radon also comes from burning natural gas (gas stove, furnace) and, if radon is present in your water supply, can be released into the air during showering and other hot water usage.
Is radon from granite countertops dangerous?
A small amount of radon can potentially come from granite countertops, but the EPA states that the amount would be much lower than the possibility of radon coming from the rocks underneath your home. Unsealed granite is one of the healthiest choices of countertop material for the kitchen. That said, if you are concerned, you could consider getting two 90 day tests— use one to take a baseline/general reading in your basement or lowest floor, and place the second one on your countertop. While this isn’t a scientifically validated method according to the EPA, it is possible that it might work and give you some peace of mind.
Is radon in water really dangerous?
Yes, radon is a gas that can dissolve into water, similar to how carbon dioxide dissolves into water to make it bubbly. It doesn’t break down, though, and accumulates, especially in groundwater and wells. When that water is used in the home for doing dishes, showering, or cooking, the radon gas then escapes into the air, where you can breathe it in and where it contributes to lung cancer risk.
How do I know if my house has a radon problem?
The zip code guidance is a good starting point, but radon can be anywhere. Radon is colorless, odorless, and tasteless, so you have to test for it.
Radon Detectors
Are radon detectors accurate?
Yes. But, how accurate they are depends on what type you use:
Short-term radon test kits (usually used when buying a new home) are an important first step, but are the least accurate overall. Over 4 days, the kit picks up on the radon levels present on the lowest floor of your home. Unfortunately, a 2019 study from Canada found that a whopping 99% of short-term tests are inaccurate! This is because radon levels fluctuate day-to-day, and throughout the year.
90-day tests are more accurate, and can be used after you’ve moved in to a new house, or if it’s been a few years since you’ve tested.
Continuous radon monitoring shows you how levels change season to season and is the most accurate of the three options for this reason.
Can I get a radon test kit for free?
Some states and counties offer free short-term test kits! It depends on your area’s risk and available funding. Check out the American Lung Association’s page on how to get one.
Where should I place a radon detector?
In your basement, or the lowest level of your house, if you don’t have a basement. That’s because radon comes from the rocks below your home.
Can dogs smell radon?
Unfortunately, you can’t use your dog as a radon detector. In 1993, a group of researchers thought it would be a great idea to test this theory out, but it looks like they never received funding to finish their study. Because it’s an odorless radioactive molecule, it’s unlikely that dogs can smell it, but who knows— maybe someday this kind of research will get more funding and we’ll be surprised. Because pets and their owners tend to get the same diseases, even if you’re not motivated to test your home for radon for yourself, testing will protect your pet, too.
What does radon smell like?
Nothing! You cannot use your sense of smell as a radon detector. Radon is completely odorless and tasteless, which is one of the reasons it’s so important to test for.
Does radon smell like rotten eggs?
No! Radon is completely odorless, so if you are smelling a rotten egg scent in your home, call your gas utility company immediately to make sure it’s not a leak. Do not light a candle, stove or matches for any reason until your house has been inspected.
Radon Mitigation
How much does installing a radon mitigation system cost?
Depending on where you live, and what type of system you want, typically between $700-$1,300, as of 2024. Please don’t let this cost deter you from testing! The cost of cancer treatment is much higher. There are also some financial assistance programs for radon mitigation; see here.
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