How to choose a radon fan (2018)
americanradonmitigation.com
americanradonmitigation.com
That's how it's possible. It's not even difficult. Unless you buy the fan on Amazon.
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.
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.
No need to try to find and calibrate some used Russian geiger counter.
Or so the thinking might go.
> 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/
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 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.
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
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.
Coal cellars in particular are/were especially common.
Yes. Building basements will cause radon to gather there.
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.
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?
What's the level you're trying to mitigate?
https://www.epa.gov/sites/default/files/2016-02/documents/20...
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.
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.
No data on Slovakia but given its neighbors situation definitely worth checking.
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!
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.
1: https://www.homedepot.com/p/LABTECH-Radon-Detection-Test-Kit... 2: https://www.homedepot.com/p/Airthings-Corentium-Home-Battery...
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.