I never cease to be amazed that the radon fan my wife had installed on the house she purchased in 1996 has run 24/7, 365 days a year, ever since, with zero maintainance. I don't know how this is even possible for an exterior electro-mechanical device.
Squirrel-cage induction motors only have one moving part, the rotor, and no semiconductors, and they can have quite a bit of clearance around the rotor, especially if efficiency isn't important. You might need to grease the bearings, and if they're rolling-element bearings, they'll wear out eventually and need to be replaced; but bearing wear is proportional to the loads on the shaft that the bearing has to resist. In a low-powered fan, a plain bearing or a reasonably sized ball bearing ought to have both MTBF and wearout time well into the decades if not centuries.
That's how it's possible. It's not even difficult. Unless you buy the fan on Amazon.
Heh. If it's 1996 I might've installed it. I'm guessing back then it was a Fantech FR100? There seem to be numerous offerings in the field now, but back then it was pretty slim pickings.
I'm in the hills of LA and we had pretty high radon readings when we moved in, so we got a couple of these fans installed.
I tried to tell my neighbors about it and they weren't interested. Same with real estate agents here. Everyone in the LA hills has got their heads in the sand.
Both my realtor and home builder told me it was mostly fake and just a scam by the government. My middle school science teacher died from cancer as a result of radon in his wine cellar. He explained to the class how radon worked, and how his measurement was so high he would almost certainly die from it. He died about 3 years later. People are still skeptical when I tell them this about him. Rip Mr. Stitt
To be fair, California has cool nights and in LA you're likely opening all your windows in the summer/spring/fall evenings to cool off your house.
Rainy weeks are the worst for radon in our house because we keep everything closed 24/7. It reaches around 6.
But our yearly average is more like 1.9. It's probably still high enough that I'll do something about it eventually, but it's not high on my priority list.
An interesting experiment to detect presence of radon at home using a geiger counter.
If you have a HEPA air purifier that has been running for a few months, then bring a geiger counter that does beta particles, near (1-2) cm of the filter and if it starts showing a lot of increased radioactivity over background readings, it means that there are radon decay elements captured in the filter panel.
I have several, ranging from $$ to $$$. Most bought on ebay. I live in Europe thus need them in case Russia or Ukraine decide to go crazy with nukes. Check ebay; GMC branded is decent Chinese one. Some of them also come with an espressif wifi card to send results to a webserver. https://www.gmcmap.com.
There are also Arduino kits that come with Soviet era geiger tubes (SBM 20).
The paranoid prepper list. Most preppers are peaceful people wanting to mind their own business, but some suffer from conditions that makes them hope for a disaster to happen to the extent that they might not shy from creating them.
Not that I know of, but there are lots of legal things that attract law enforcement attention these days, depending on where you live: tattoos, cash transactions, fertilizer, VPN services, borax, red phosphorus, gas masks, numerous visitors, and so on.
Unless you mean "specific tattoos", having no tattoos is probably more anomalous for people under a certain age. I would the cutoff is within the broad range of 35-50.
As I said, it depends on where you live. Here in Argentina having no tattoos is more anomalous than having them for people in the 35–50 range, just as you say; but in Japan they mark you as a criminal, in Iran they're a symbol of rejection of the theocracy, in PRC it's illegal to show them on TV, and Erykah Badu is banned from performing in Malaysia because she has "Allah" tattooed across her shoulders. Both the Yazidis and the Kurds have tattoo traditions that have at times been persecuted by Daesh, Iran, and Turkey; I don't know how active that phenomenon is at the moment.
Never heard of people using these before. Is there a significant risk in general? And is the risk greater/lesser in certain areas of the globe? (am guessing granite seams might have an impact since i understand they give off radon)
I had never heard of it until I bought a house recently and the home inspector was adamant about recommending a radon inspection at some point, not even from him. I mentioned it to another friend who had built a house recently and he said radon mitigation systems were mandatory in his new neighborhood.
> Radon is the #1 cause of cancer after smoking and kills more than 21,000 Americans every year. - https://www.radonawareness.org/
The combo of smoking and high household radon is particularly bad; there's a 1 in 3 lifetime chance of lung cancer for people who have both risk factors.
Sounds like the perfect murder weapon. Can it be collected in quantity? Has any of the myriad of whodunnit shows and films ever used it as a plot device? I guess it's only useful for immediate death if in such quantity to displace air, and other gases are safer and more easily acquired, such as CO2. But if there is no rush...
Radon is dangerous because when it decays, it decays in to tiny particles of radioactive dust that get embedded in your lungs. Decades of exposure get you lung cancer.
Radon has a half life of less than 4 days, you would need a shitload of uranium in order to accumulate enough radon as a decay product in order to be acutely deadly to anyone.
Like it would probably be easier to build a nuclear weapon than to murder somebody with radon.
Likewise intentionally trying to get someone addicted to cigarettes would be a more effective “murder” weapon.
There is a significant risk in general, but it depends on your housing type. Radon's half-life is 3.8 days, so roughly only the radon produced by the uranium in your house in the last week or two is of concern; it can't build up over longer periods of time. But if there are areas that are sealed well enough that radon can accumulate for days, but not sealed so well that radon is sealed inside the wall until it decays, you could have a high level in the air.
There are some minerals that have relatively high concentrations of uranium, but no rocks are completely devoid of it. Consequently any rock, sand, dirt, or concrete has some amount of U-238, which decays (through the four or five intermediate steps of the so-called radium series) to radium-226, which produces radon-222. Radium-226 has a half-life of 1600 years, so if you were to remove all the radium from a rock, it would stop emanating radon and take millennia to ramp back up to its previous radon emanation level. But the reason we use these natural minerals for construction in the first place is that they're cheap, and this is not cheap, so we don't do it.
Radon decays through a variety of seven radioactive steps, six of which are ridiculously more radioactive than radon itself (radioisotopes of lead, bismuth, and polonium). The reason we worry about the radon instead of its even more radioactive products is that it's chemically inert, so it just floats around as a gas instead of staying put in the rock or settling out of the air, and so when it finally breaks down into polonium, it might happen to be inside human lungs, and that's where the polonium atom is going to stay, giving off three alpha rays and two beta rays over the next hour or so, until it decays into comparatively harmless radioactive lead.
Alpha rays are normally absolutely harmless to the humans because a few microns of anything solid will stop them, and the human skin is covered in tens of microns of epidermis cells that have no nuclei or blood supply and therefore can't get cancer. And beta rays are only a little more penetrating. But inside the lungs it's a different story, and that's why so much lung cancer is caused by radon.
Because radon's half-life is so short, and the resulting decay chain effectively multiplies its radioactivity by 5, it's almost inconceivably more radioactive than the radium that emanates it: a mole of radium-226 would be 226 grams, containing 6×10²³ atoms, and if I'm doing my calculation right that's 8×10¹² becquerels (decays per second). A mole of radon-222 weighs 222 grams and by the same calculation produces 1.3×10¹⁸ becquerels itself, 6.4×10¹⁸ becquerels if you include the next four steps in the decay chain. (Calculation in units(1): avogadro mol / (3.8 days / ln(2))). That's nearly a million times as much radioactivity per gram, and radium is already no slouch in that department.
Of course, in any given year, the amount of radon that decays in your house is almost exactly the same as the amount of radium that decays (since almost every radium atom that decays becomes a radon atom, which decays within a week or two), so the radon only produces 5 times as much radioactivity as the radium. If it stayed inside the wall instead of gadding about in human lungs it wouldn't be an issue.
>There is a long tradition in Europe, going back to the Greeks and Romans, of seeking out thermal springs for their healing and soothing properties. The hot springs (thermae in Latin) were considered sacred, and exposure to the mineral waters was thought to be healing ... it is the cumulative dose that one is exposed to over a lifetime that is thought to determine one’s risk of lung cancer. Thus, a few hours of elevated radon exposure in the course of a year will not result in a large increase in one’s average exposure level. This is recognized in the limits to time spent in the Mine Gallery.
Interesting, though I seem to have skipped the prerequisite reading of 'why we are concerned about radon in our homes and having radon fans installed'.
Here's an interactive map for the UK. (Note it shows grades of probability of a home having too high (>200 Bq/m^3) a level, not grades of absolute level in the ground or something in different areas.) https://www.ukradon.org/information/ukmaps
Well, we do, and are you implying that we have a lot of it? The map of Germany someone else shared looked at a glance 'worse', the post is from a US company that installs mitigations (is that ever done here? I've never heard of it before).
I don't disagree with the 'vast majority' not having them, but I don't think it's S unusual as you imply either. Probably the vast majority don't have an en suite bathroom either (I don't mean to imply a complete intersection, these are two 'vast majority' circles in a Venn diagram), but the new builds have multiple.
Coal cellars in particular are/were especially common.
Are there any systems that a homeowner can install themselves or do they all involve breaking the slab, excavating dirt, installing vents to the exterior, and wiring up a fan?
Back in college I installed these so hopefully I can be helpful. You don’t need to break slab, that vast majority of homes you’ll just connect the pipe to the sump pump cover. They actually sell covers just for this.
The most difficult part is drilling through your home (assuming you don’t already have a passive system installed). Other than that you really don’t need any crazy tools.
Assuming you have a pretty typical home and are fairly handy I’d budget 10-20 man hours.
Unfortunately I don’t have a sump pump. Perhaps because the house is built on a hill?
How does one know where to drill the relief hole, and wouldn’t you need holes in a variety of locations depending on size of the house? My house is a split level, so there are two slabs, and presumably would need two holes, minimum?
You drill in the lowest part of the basement. That’s where the radon accumulates. Don’t do this yourself. Hire someone who does it regularly so it’s done right. It costs under $2000. Test before and after. I have a continuous radon digital monitor.
I’d start with one hole and test your levels. There’s a very high likelihood you wouldn’t have to drill more than one. With that said it may make sense to just hire someone.
Active sub-slab depressurization is only indicated if all the passive measures have failed. First, caulk the slab-to-wall joints, seal the sump pump cover to the slab, caulk any cracks in the slab, etc. Then test again.
It was up around 250 Bq/m^3 at its peak, and then I cracked open the two basement windows and it has since dropped to around 110 Bq/m^3. In Canada the recommendations are to deal with it ASAP if over 200, and to deal with it within the next 2 years if it is 100-200.
I’ve looked and don’t see any cracks in the slab, but admittedly 1/2 of the basement is carpeted and drywalled and so I don’t have a good view of it.
I use the AirThings View Plus, and note that it has been running for 2.5 months, and I want to see what it settles at as a longer term average.
Realistically, popping a hole in the slab and installing a fan might be less disruptive than tearing out all the finishing.
Do you have a sump? First, seal it. Caulk as much of the wall-floor joint as you can. If it's still not low enough, add a fan _to the sump cover_, since the weep-tile system might provide all the sub-slab vapor communication you need without adding any new holes.
Can radon come in through the walls? We recently got a crack in the basement wall and a small water leak. Will be fixing the leak next spring, but I am curious if this is a cause for higher readings. The long term average is about 135 but it occasionally spikes to 200+. Also in Canada.
Technically yes. It's a gas, so it'll permeate through anything that's gas-permeable. And being a noble gas, it's pretty small, not as small as Helium, but still it'll wander right through membranes that're gas-tight for diatomic molecules and larger compounds.
However, that is almost always a rounding-error in terms of basement soil-gas infiltration. You can sometimes feel a literal breeze coming through a crack if the house is badly depressurized (windy day and stack-effect), you will never feel a breeze coming straight through a solid concrete or cinder-block wall.
The spikes probably come from depressurization events like that. Sometimes the wind is angled in such a way that the house effectively forms a whistle or a manometer, and soil gas migrates at a greater rate during those times.
This is somewhere that _passive_ sub-slab ventilation (drill a hole, connect a vent pipe to the outside, no fan) can often help significantly, along with caulking all the cracks. Seriously, don't bother with anything else until you've caulked.
I rent a house. Both houses on either side of me have radon vents, mine does not. But I can see they've got basements, mine is on slab (no basement or crawlspace). I asked the landlord if this house was ever tested, he said not to worry since there is no basement. Is there an easy, reliable way for me to test for radon, or am I worrying too much?
Yes, if tampering isn't a concern, the at-home test kits are cheap and reliable. (Edit: In a real-estate transaction, there's plenty of incentive to cheat, so the continuous-monitors used in those situations include all sorts of other sensors -- accelerometers, temperature and humidity, barometric pressure, etc -- to tell if someone just opens all the windows, or carries it outside, etc. My dad used to do this work and I saw some wacky printouts indeed, from where unscrupulous agents had gone to any length to make sure the test produced a low reading.)
Charcoal canisters are cheaper but only do a short-term snapshot. Get an alpha-track and do a long-term test, which gives you a much more reliable picture of your exposure. You can absolutely do both. There are also continuous monitors which are more expensive still, but some folks just love live data.
If you hadn't mentioned neighbors on both sides, I'd say as a slab-dweller, you might be worrying too much. But that definitely points to uranium in the local soil, and while slabs are generally at significantly lower risk than basements, your situation is one where it's definitely worth testing!
Note that a basement doesn't necessarily matter. We have slab-on-grade and our radon levels are borderline "do something about it" - our yearly average seems to be around 2.0.
Follow the instructions to the letter (use the hole, tie a string to it and suspend the test in the middle of the room, in an area away from traffic and away from air currents).
I recommend using two, on opposite sides of the room.
Then leave it there for a year. Many places have seasonal variation in radon, so while you can do a 3 month test, I recommend a 1 year test.
Is there a passive way to do this in off grid homes? Open the windows, I guess, but I wonder if there are more advanced window types that can funnel the breeze in and out with proper planning. Or automated window openings. What would the over/under on energy consumption be there? /ramble
I never cease to be amazed that the radon fan my wife had installed on the house she purchased in 1996 has run 24/7, 365 days a year, ever since, with zero maintainance. I don't know how this is even possible for an exterior electro-mechanical device.
Squirrel-cage induction motors only have one moving part, the rotor, and no semiconductors, and they can have quite a bit of clearance around the rotor, especially if efficiency isn't important. You might need to grease the bearings, and if they're rolling-element bearings, they'll wear out eventually and need to be replaced; but bearing wear is proportional to the loads on the shaft that the bearing has to resist. In a low-powered fan, a plain bearing or a reasonably sized ball bearing ought to have both MTBF and wearout time well into the decades if not centuries.
That's how it's possible. It's not even difficult. Unless you buy the fan on Amazon.
Heh. If it's 1996 I might've installed it. I'm guessing back then it was a Fantech FR100? There seem to be numerous offerings in the field now, but back then it was pretty slim pickings.
Fantech is now at the high end of pricing, with (most? all?) motors still made in Germany for fans assembled in USA.
They are amazingly durable, but they can't handle a (now dead) chipmunk :(
I'm in the hills of LA and we had pretty high radon readings when we moved in, so we got a couple of these fans installed.
I tried to tell my neighbors about it and they weren't interested. Same with real estate agents here. Everyone in the LA hills has got their heads in the sand.
Both my realtor and home builder told me it was mostly fake and just a scam by the government. My middle school science teacher died from cancer as a result of radon in his wine cellar. He explained to the class how radon worked, and how his measurement was so high he would almost certainly die from it. He died about 3 years later. People are still skeptical when I tell them this about him. Rip Mr. Stitt
To be fair, California has cool nights and in LA you're likely opening all your windows in the summer/spring/fall evenings to cool off your house.
Rainy weeks are the worst for radon in our house because we keep everything closed 24/7. It reaches around 6.
But our yearly average is more like 1.9. It's probably still high enough that I'll do something about it eventually, but it's not high on my priority list.
Our house was at 14 when we moved in. With mitigation it's now down between 1-2.
Wow yeah, that's pretty high. Hah.
An interesting experiment to detect presence of radon at home using a geiger counter. If you have a HEPA air purifier that has been running for a few months, then bring a geiger counter that does beta particles, near (1-2) cm of the filter and if it starts showing a lot of increased radioactivity over background readings, it means that there are radon decay elements captured in the filter panel.
Kinda cool, but if you want radon levels why not buy a radon detector? Like this one: https://www.airthings.com/wave-plus
No need to try to find and calibrate some used Russian geiger counter.
What Geiger counter do you recommend? Will buying one get you put on a list?
I have several, ranging from $$ to $$$. Most bought on ebay. I live in Europe thus need them in case Russia or Ukraine decide to go crazy with nukes. Check ebay; GMC branded is decent Chinese one. Some of them also come with an espressif wifi card to send results to a webserver. https://www.gmcmap.com. There are also Arduino kits that come with Soviet era geiger tubes (SBM 20).
Thanks! Uh, maybe I can just use a solar cell or something.
A marketing list, maybe.
List? Is it now illegal to measure radiation?
The paranoid prepper list. Most preppers are peaceful people wanting to mind their own business, but some suffer from conditions that makes them hope for a disaster to happen to the extent that they might not shy from creating them.
Or so the thinking might go.
Not that I know of, but there are lots of legal things that attract law enforcement attention these days, depending on where you live: tattoos, cash transactions, fertilizer, VPN services, borax, red phosphorus, gas masks, numerous visitors, and so on.
Unless you mean "specific tattoos", having no tattoos is probably more anomalous for people under a certain age. I would the cutoff is within the broad range of 35-50.
As I said, it depends on where you live. Here in Argentina having no tattoos is more anomalous than having them for people in the 35–50 range, just as you say; but in Japan they mark you as a criminal, in Iran they're a symbol of rejection of the theocracy, in PRC it's illegal to show them on TV, and Erykah Badu is banned from performing in Malaysia because she has "Allah" tattooed across her shoulders. Both the Yazidis and the Kurds have tattoo traditions that have at times been persecuted by Daesh, Iran, and Turkey; I don't know how active that phenomenon is at the moment.
Very true.
Never heard of people using these before. Is there a significant risk in general? And is the risk greater/lesser in certain areas of the globe? (am guessing granite seams might have an impact since i understand they give off radon)
I had never heard of it until I bought a house recently and the home inspector was adamant about recommending a radon inspection at some point, not even from him. I mentioned it to another friend who had built a house recently and he said radon mitigation systems were mandatory in his new neighborhood.
> Radon is the #1 cause of cancer after smoking and kills more than 21,000 Americans every year. - https://www.radonawareness.org/
See also https://www.cdc.gov/radon/
The combo of smoking and high household radon is particularly bad; there's a 1 in 3 lifetime chance of lung cancer for people who have both risk factors.
Yes radon highly depends on your local geology, home construction, and chance.
Sounds like the perfect murder weapon. Can it be collected in quantity? Has any of the myriad of whodunnit shows and films ever used it as a plot device? I guess it's only useful for immediate death if in such quantity to displace air, and other gases are safer and more easily acquired, such as CO2. But if there is no rush...
It’s a terrible weapon.
Radon is dangerous because when it decays, it decays in to tiny particles of radioactive dust that get embedded in your lungs. Decades of exposure get you lung cancer.
Radon has a half life of less than 4 days, you would need a shitload of uranium in order to accumulate enough radon as a decay product in order to be acutely deadly to anyone.
Like it would probably be easier to build a nuclear weapon than to murder somebody with radon.
Likewise intentionally trying to get someone addicted to cigarettes would be a more effective “murder” weapon.
Thank you for entertaining and enhancing the ridiculous by being straight.
There is a significant risk in general, but it depends on your housing type. Radon's half-life is 3.8 days, so roughly only the radon produced by the uranium in your house in the last week or two is of concern; it can't build up over longer periods of time. But if there are areas that are sealed well enough that radon can accumulate for days, but not sealed so well that radon is sealed inside the wall until it decays, you could have a high level in the air.
There are some minerals that have relatively high concentrations of uranium, but no rocks are completely devoid of it. Consequently any rock, sand, dirt, or concrete has some amount of U-238, which decays (through the four or five intermediate steps of the so-called radium series) to radium-226, which produces radon-222. Radium-226 has a half-life of 1600 years, so if you were to remove all the radium from a rock, it would stop emanating radon and take millennia to ramp back up to its previous radon emanation level. But the reason we use these natural minerals for construction in the first place is that they're cheap, and this is not cheap, so we don't do it.
Radon decays through a variety of seven radioactive steps, six of which are ridiculously more radioactive than radon itself (radioisotopes of lead, bismuth, and polonium). The reason we worry about the radon instead of its even more radioactive products is that it's chemically inert, so it just floats around as a gas instead of staying put in the rock or settling out of the air, and so when it finally breaks down into polonium, it might happen to be inside human lungs, and that's where the polonium atom is going to stay, giving off three alpha rays and two beta rays over the next hour or so, until it decays into comparatively harmless radioactive lead.
Alpha rays are normally absolutely harmless to the humans because a few microns of anything solid will stop them, and the human skin is covered in tens of microns of epidermis cells that have no nuclei or blood supply and therefore can't get cancer. And beta rays are only a little more penetrating. But inside the lungs it's a different story, and that's why so much lung cancer is caused by radon.
Because radon's half-life is so short, and the resulting decay chain effectively multiplies its radioactivity by 5, it's almost inconceivably more radioactive than the radium that emanates it: a mole of radium-226 would be 226 grams, containing 6×10²³ atoms, and if I'm doing my calculation right that's 8×10¹² becquerels (decays per second). A mole of radon-222 weighs 222 grams and by the same calculation produces 1.3×10¹⁸ becquerels itself, 6.4×10¹⁸ becquerels if you include the next four steps in the decay chain. (Calculation in units(1): avogadro mol / (3.8 days / ln(2))). That's nearly a million times as much radioactivity per gram, and radium is already no slouch in that department.
Of course, in any given year, the amount of radon that decays in your house is almost exactly the same as the amount of radium that decays (since almost every radium atom that decays becomes a radon atom, which decays within a week or two), so the radon only produces 5 times as much radioactivity as the radium. If it stayed inside the wall instead of gadding about in human lungs it wouldn't be an issue.
In Austria people pay to go down an old mine and soak in the radon for their health. It's an odd world.
interesting! https://www.forbes.com/sites/geoffreykabat/2019/02/02/in-ger...
>There is a long tradition in Europe, going back to the Greeks and Romans, of seeking out thermal springs for their healing and soothing properties. The hot springs (thermae in Latin) were considered sacred, and exposure to the mineral waters was thought to be healing ... it is the cumulative dose that one is exposed to over a lifetime that is thought to determine one’s risk of lung cancer. Thus, a few hours of elevated radon exposure in the course of a year will not result in a large increase in one’s average exposure level. This is recognized in the limits to time spent in the Mine Gallery.
I feel so damn lucky to live in a country where radon isn't a thing we have to think about.
Interesting, though I seem to have skipped the prerequisite reading of 'why we are concerned about radon in our homes and having radon fans installed'.
Here's an interactive map for the UK. (Note it shows grades of probability of a home having too high (>200 Bq/m^3) a level, not grades of absolute level in the ground or something in different areas.) https://www.ukradon.org/information/ukmaps
Yep, and that's one of the reasons we don't have basements in this country.
Well, we do, and are you implying that we have a lot of it? The map of Germany someone else shared looked at a glance 'worse', the post is from a US company that installs mitigations (is that ever done here? I've never heard of it before).
Houses built in the past 100 years generally don't.
There is a subset of the Victorian terrace townhouses in some of the major cities that do, but the vast majority of houses do not.
The water table is one reason, but radon mitigation is certainly a constraint.
I don't disagree with the 'vast majority' not having them, but I don't think it's S unusual as you imply either. Probably the vast majority don't have an en suite bathroom either (I don't mean to imply a complete intersection, these are two 'vast majority' circles in a Venn diagram), but the new builds have multiple.
Coal cellars in particular are/were especially common.
And somehow the extra 8 feet of dirt magically protects you from radon?
Radon is heavier than air, and completely inert.
Yes. Building basements will cause radon to gather there.
Are there any systems that a homeowner can install themselves or do they all involve breaking the slab, excavating dirt, installing vents to the exterior, and wiring up a fan?
Back in college I installed these so hopefully I can be helpful. You don’t need to break slab, that vast majority of homes you’ll just connect the pipe to the sump pump cover. They actually sell covers just for this.
The most difficult part is drilling through your home (assuming you don’t already have a passive system installed). Other than that you really don’t need any crazy tools.
Assuming you have a pretty typical home and are fairly handy I’d budget 10-20 man hours.
Unfortunately I don’t have a sump pump. Perhaps because the house is built on a hill?
How does one know where to drill the relief hole, and wouldn’t you need holes in a variety of locations depending on size of the house? My house is a split level, so there are two slabs, and presumably would need two holes, minimum?
You drill in the lowest part of the basement. That’s where the radon accumulates. Don’t do this yourself. Hire someone who does it regularly so it’s done right. It costs under $2000. Test before and after. I have a continuous radon digital monitor.
I’d start with one hole and test your levels. There’s a very high likelihood you wouldn’t have to drill more than one. With that said it may make sense to just hire someone.
Active sub-slab depressurization is only indicated if all the passive measures have failed. First, caulk the slab-to-wall joints, seal the sump pump cover to the slab, caulk any cracks in the slab, etc. Then test again.
What's the level you're trying to mitigate?
https://www.epa.gov/sites/default/files/2016-02/documents/20...
It was up around 250 Bq/m^3 at its peak, and then I cracked open the two basement windows and it has since dropped to around 110 Bq/m^3. In Canada the recommendations are to deal with it ASAP if over 200, and to deal with it within the next 2 years if it is 100-200.
I’ve looked and don’t see any cracks in the slab, but admittedly 1/2 of the basement is carpeted and drywalled and so I don’t have a good view of it.
I use the AirThings View Plus, and note that it has been running for 2.5 months, and I want to see what it settles at as a longer term average.
> 1/2 of the basement is carpeted and drywalled
Realistically, popping a hole in the slab and installing a fan might be less disruptive than tearing out all the finishing.
Do you have a sump? First, seal it. Caulk as much of the wall-floor joint as you can. If it's still not low enough, add a fan _to the sump cover_, since the weep-tile system might provide all the sub-slab vapor communication you need without adding any new holes.
Can radon come in through the walls? We recently got a crack in the basement wall and a small water leak. Will be fixing the leak next spring, but I am curious if this is a cause for higher readings. The long term average is about 135 but it occasionally spikes to 200+. Also in Canada.
Technically yes. It's a gas, so it'll permeate through anything that's gas-permeable. And being a noble gas, it's pretty small, not as small as Helium, but still it'll wander right through membranes that're gas-tight for diatomic molecules and larger compounds.
However, that is almost always a rounding-error in terms of basement soil-gas infiltration. You can sometimes feel a literal breeze coming through a crack if the house is badly depressurized (windy day and stack-effect), you will never feel a breeze coming straight through a solid concrete or cinder-block wall.
The spikes probably come from depressurization events like that. Sometimes the wind is angled in such a way that the house effectively forms a whistle or a manometer, and soil gas migrates at a greater rate during those times.
This is somewhere that _passive_ sub-slab ventilation (drill a hole, connect a vent pipe to the outside, no fan) can often help significantly, along with caulking all the cracks. Seriously, don't bother with anything else until you've caulked.
Reading these comments, and seeing that I live in a red area of Germany on this map https://www.fs-ev.org/fileadmin/user_upload/97_Service/Radon..., I'm sure glad that my apartment is on the first floor (and the bedroom on the second floor).
An incomplete European map is available at https://www.eea.europa.eu/data-and-maps/figures/european-ind...
No data on Slovakia but given its neighbors situation definitely worth checking.
I rent a house. Both houses on either side of me have radon vents, mine does not. But I can see they've got basements, mine is on slab (no basement or crawlspace). I asked the landlord if this house was ever tested, he said not to worry since there is no basement. Is there an easy, reliable way for me to test for radon, or am I worrying too much?
Yes, if tampering isn't a concern, the at-home test kits are cheap and reliable. (Edit: In a real-estate transaction, there's plenty of incentive to cheat, so the continuous-monitors used in those situations include all sorts of other sensors -- accelerometers, temperature and humidity, barometric pressure, etc -- to tell if someone just opens all the windows, or carries it outside, etc. My dad used to do this work and I saw some wacky printouts indeed, from where unscrupulous agents had gone to any length to make sure the test produced a low reading.)
Charcoal canisters are cheaper but only do a short-term snapshot. Get an alpha-track and do a long-term test, which gives you a much more reliable picture of your exposure. You can absolutely do both. There are also continuous monitors which are more expensive still, but some folks just love live data.
If you hadn't mentioned neighbors on both sides, I'd say as a slab-dweller, you might be worrying too much. But that definitely points to uranium in the local soil, and while slabs are generally at significantly lower risk than basements, your situation is one where it's definitely worth testing!
Note that a basement doesn't necessarily matter. We have slab-on-grade and our radon levels are borderline "do something about it" - our yearly average seems to be around 2.0.
We went with https://www.homedepot.com/p/Airthings-Corentium-Home-Battery... which the other commenter suggested as a more expensive solution.
I bought this because California county Radon maps showed us in a "tan" area, meaning "moderate" risk of Radon above 4.0. Here's an example of one such map: https://www.conservation.ca.gov/cgs/Documents/Publications/S...
Note that radon levels varied greatly in our house by both weather and time of year.
There are cheap low-tech solutions [1] and more expensive high-tech [2]
1: https://www.homedepot.com/p/LABTECH-Radon-Detection-Test-Kit... 2: https://www.homedepot.com/p/Airthings-Corentium-Home-Battery...
Buy this: https://smile.amazon.com/gp/product/B003C5BZYA/
Follow the instructions to the letter (use the hole, tie a string to it and suspend the test in the middle of the room, in an area away from traffic and away from air currents).
I recommend using two, on opposite sides of the room.
Then leave it there for a year. Many places have seasonal variation in radon, so while you can do a 3 month test, I recommend a 1 year test.
you can get an airthings device like the view plus[0] (i actually have the older wave plus) for continuous sampling of your radon levels.
[0]: https://www.airthings.com/view-plus
Is there a passive way to do this in off grid homes? Open the windows, I guess, but I wonder if there are more advanced window types that can funnel the breeze in and out with proper planning. Or automated window openings. What would the over/under on energy consumption be there? /ramble
Just have a crawl space instead of a house directly on a slab.