Radon levels in home

Triple digit golfer · Post by **Triple digit golfer** » Sat Jun 15, 2019 9:27 pm

When we bought our house three years ago, we had the realtor arrange for a radon test. The two lowest rooms were tested. The basement was 7.7 and the family room on a slab was 2.2. The EPA says 4.0 is the level at which they recommend remediation.

We only use our basement (unfinished) for storage, so I wasn't concerned at the time.

However, I have no idea how accurate a 48 hour test is.

Additionally, we just had a new furnace and air conditioner installed and the furnace has a variable speed motor, which means the fan is always on, taking air from the entire house and essentially recirculating it to eliminate temperature fluctuations. Therefore, I am mildly concerned that the higher levels in the basement may raise the levels in the rest of the house. In other words, if the basement was 7.7 and rest of the house 2.2, maybe now the entire house is say, 5.0. I'm not sure if the fan always running would even affect it, though.

Should I be concerned or am I falling for a false hysteria?

Am I essentially scaring myself over a very small risk, equivalent to say, not going outside for fear of getting hit by a meteorite?

I've seen the charts about risk of lung cancer and they all assume a lifetime of breathing only the air at radon levels of X. Smoking poses a much, much higher risk. Hell, my diet of french fries a few times a week is probably a bigger carcinogen than radon gas.

Any insight, opinions or experiences are appreciated.

fortfun · Post by **fortfun** » Sat Jun 15, 2019 10:24 pm

Is your basement plumbed with a passive radon pipe leading out the roof? If so, you can put a $150 fan, in the attic, to pull the air out through the roof. I did that to mine, it was about a half day job, including adding a 110V plug near the power fan.

MP123 · Post by **MP123** » Sat Jun 15, 2019 10:34 pm

Radon is related to geology and soil types, it can be an issue in some parts of the country but not others.

I was curious about the levels in our house and got a 48hr test kit from Amazon. Cheap but you have to mail it in after exposing the carbon for 48hrs. I don't recall the exact numbers but they were much lower than where one would be concerned, results emailed back.

My guess is that you're scaring yourself over nothing but if Radon is an issue in your area it's easy to test any room in your house yourself.

Jazzysoon · Post by **Jazzysoon** » Sat Jun 15, 2019 10:40 pm

You don't mention where you live or time of year of test. For example in the upper Midwest a test in winter on upper levels when windows are closed and not much outside airflow will be higher than spring/summer/fall with windows open. My county has test kits, if I were you I'd close up the house and do more tests in upper level where you spend most of your time. For me I have never smoked, and I don't want to risk lung cancer from my house which had tested high when I purchased it. A remediation system was put in prior to my final purchase and I get it checked periodically. It initially tested at 12, it's down to .04 with mitigation system. System has fan/meter so you can tell when it's running.

bhsince87 · Post by **bhsince87** » Sat Jun 15, 2019 10:45 pm

I was paranoid about radon in our home for many years. We tested marginal when we bought the home.

I spent $150 (on sale) for a continuous electronic monitor. The Wave from these folks. https://www.airthings.com/en-us/homeowners.

HAd it about 2 years now, and it's been enlightening!

Our basement definitely has the highest levels. Generally runs around 2-3, but sometimes gets up to 4 to 4.5., or the yellow zone.

Occasionally , our living area passes 4.0, but not very often.

The levels seem to be related to air pressure, and who knows what else. Closeness of the moon maybe?

Anyway, I've also placed it outside on the soil surface, and I get almost the same readings. So it's not building up in our house.

I've also tested our bathrooms as we shower with well water, because I've read that can be an unexpected source. Found no problems there either.

I have tons of data now. So I've stopped worrying about it. The money I spent on that detector was definitely worth the peace of mind!

Student2 · Post by **Student2** » Sat Jun 15, 2019 11:16 pm

I would recommend that you test. Depending on what you find, you may want to take steps to lower radon levels in your home. Most homes are pretty leaky, so even if you're recirculating air, the radon level of the recirculated air will probably not tend to be a simple average of the upstairs and downstairs levels. That said, it doesn't hurt to be cautious when it comes to radiation levels you can control. All of this assumes you don't smoke. If you, or anyone in your home smokes, then you should definitely test and make sure levels are well below the recommended threshold. There is evidence that radon and smoking have a synergistic relationship with regard to lung cancer.

I posted a response to another radon question a while ago and I've pasted it below. The image that wouldn't quote, is just below that.

I am an epidemiologist and worked in cancer research for many years. I echo what adamthesmythe commented to you. 4.0 pCi/L was the level agreed upon by a governmental and scientific organizations (e.g., CDC, American Lung Association, etc.) ( Radon Fact Sheet at cancer.gov). A slightly higher action threshold is used in Canada (Health Canada 2009, at ~5.4 pCi/L) and a lower one is recommended by the WHO (WHO Handbook on Indoor Radon, 2.7 pCi/L), but it's important to note that there is no known level of radiation that is free of risk. Based on this, I personally would not recommend long-term exposure to a basement/dwelling that was merely below the actionable threshold (and yes, I live in radon country and I would consider 'long-term' to mean any regular occupation of a space with radon levels anywhere near 4). This is just my personal philosophy, but I would not be happy with mitigation that left levels above 1 pCi/L, and the lower the better. Smokers may also be at substantially elevated risk of developing lung cancer when exposed to radon and should consider mitigation below the actionable level.

Cancer takes decades to develop to the point that it causes symptoms or can be detected, so it is hard to draw connections between exposure to radon and development of lung cancer in the future, but the evidence for the link between radon and lung cancer is solid. There is no question that radiation causes cancer or that radon causes lung cancer. The evidence was collected from miners exposed to radon in occupational settings. The only part that may be a little less clear is the shape of the mathematical relationship between cancer and lower levels of radiation. I didn't research the most recent literature on this, but I'm happy to assume the relationship is linear all the way down below what most homeowners could reasonably be expected to measure.

One way to think about this is suggested by the Canadian government website's public information on radon (see below).

"This chart is intended to give you a visual comparison of the risk from radon exposure as a non-smoker and the risk due to other more commonly understood hazards, such as accidental deaths from car accidents, drownings, falls, fires, etc. From the chart you can see that as the radon level increases the risk of death due to radon exposure becomes greater than that for all common accidental deaths combined. We take precautions everyday to prevent accidental deaths by wearing seat belts, wearing life jackets or changing the batteries in the smoke detector, we should also be testing our homes for radon and reducing the levels if they are high!"

Image

(Edited to add: 1000 Bq/m^3 approx. = 27.0pCi/L; 800 Bq/m^3 approx. = 21.6 PCi/L; 400 Bq/m^3 approx. = 10.8 PCi/L; 200 Bq/m^3 approx. = 5.4 PCi/L; 50 Bq/m^3 approx. = 1.4 PCi/L)

OnTrack · Post by **OnTrack** » Sat Jun 15, 2019 11:58 pm

Triple digit golfer wrote: ↑
Sat Jun 15, 2019 9:27 pm
Additionally, we just had a new furnace and air conditioner installed and the furnace has a variable speed motor, which means the fan is always on, taking air from the entire house and essentially recirculating it to eliminate temperature fluctuations.

I have a furnace with a variable speed motor, but it does not run all the time. I can set it to run all the time by a setting on the thermostat. In any case, I agree that you should try to keep radon levels below the recommended maximum.
You can buy an electronic radon gas detector so you can test multiple locations under various conditions without sending a kit into a lab for each test.

mmmodem · Post by **mmmodem** » Sun Jun 16, 2019 2:46 am

bhsince87 wrote: ↑
Sat Jun 15, 2019 10:45 pm
I was paranoid about radon in our home for many years. We tested marginal when we bought the home.

I spent $150 (on sale) for a continuous electronic monitor. The Wave from these folks. https://www.airthings.com/en-us/homeowners.

HAd it about 2 years now, and it's been enlightening!

Our basement definitely has the highest levels. Generally runs around 2-3, but sometimes gets up to 4 to 4.5., or the yellow zone.

Occasionally , our living area passes 4.0, but not very often.

The levels seem to be related to air pressure, and who knows what else. Closeness of the moon maybe?

Anyway, I've also placed it outside on the soil surface, and I get almost the same readings. So it's not building up in our house.

I've also tested our bathrooms as we shower with well water, because I've read that can be an unexpected source. Found no problems there either.

I have tons of data now. So I've stopped worrying about it. The money I spent on that detector was definitely worth the peace of mind!

Ditto above.

Mine fluctuates between 0.2 and 4.0 but averages around 1.0. It goes up and down. It does not seem to correspond to temperature, precipitation, humidity, daylight or season. It appears completing random.

The only thing that seems to affect it is when I use air conditioning, heater, dehumidifier, or when we go on vacation. It goes up. This makes sense as positive pressure pulls radon from the soil and this builds up inside the house. As all the doors and windows are closed in winter or when we go on vacation, radon builds up more easily in winter.

I think radon is mostly mass hysteria because we don't know what a safe level is. There may not be a safe level but the EPA has set 4.0 as the action level. All the research I've done shows nothing particular about 4.0. it seems like an arbitrary level. Anyway I have a radon detector because my home was tested at 3.6 before we purchased. Because 4.0 is the limit, that will affect resale value and therefore I purchased a continuous radon monitor. On Amazon, it's $200 usually but often has a $50 coupon.

mortfree · Post by **mortfree** » Sun Jun 16, 2019 4:37 am

You should have had a radon fan or radon mitigation system installed as part of the real estate transaction.

I would look into that now otherwise you will probably have to install one when you sell the house since you are above the action level in the basement.

plannerman · Post by **plannerman** » Sun Jun 16, 2019 5:59 am

Here radon tests are pretty much a standard part of home inspections. When you eventually want to sell your house, you will probably have to remediate the radon to sell it--regardless of whether it's a significant health hazard or not. You might as well do it now and get it over-with.

plannerman

mmcmonster · Post by **mmcmonster** » Sun Jun 16, 2019 6:17 am

I'm surprised that your mortgage company allowed you to buy the home without having radon remediation addressed.

Where I am (North East PA), you have to get your Radon remediation done by someone licensed by the state. I bought a continuous radon detector with a built-in alarm from amazon ( https://www.amazon.com/gp/product/B000C ... UTF8&psc=1 ). It correlated quite closely with the professional checks we had done.

We actually own two of the monitors. One we keep in the basement, the other on the second floor. It actually became useful one year, when the radon remediation pipe (which was originally put in by a handyman, not a professional) dislodged and pumped the gas into the second floor bedroom.

Needless to say, we got it redone by a specialist.

In addition, my wife had found a link from the state government where they sent us a free meter to check the basement for an entire year (!) and send the monitor back to them for analysis.

Call_Me_Op · Post by **Call_Me_Op** » Sun Jun 16, 2019 6:36 am

The 4 pCi/L EPA action limit is arbitrary. This is equivalent to something like 200 chest x-rays per year. Unless you believe this is all hype, there is no proven safe level for ionizing radiation - it is a statistical "game." I would rather minimize any exposure above the unavoidable background.

Michael Patrick · Post by **Michael Patrick** » Sun Jun 16, 2019 9:12 am

I spend a good amount of time down in my basement. My office is down here as is all of my musical gear.

I don't remember exactly what the reading was when I had it tested, but it was over the limit. I had a remediation system installed. They installed an exhaust fan that draws the air up through my sump pump well. It cost around $700 if I'm remembering right.

rkhusky · Post by **rkhusky** » Sun Jun 16, 2019 9:19 pm

OnTrack wrote: ↑
Sat Jun 15, 2019 11:58 pm

Triple digit golfer wrote: ↑
Sat Jun 15, 2019 9:27 pm
Additionally, we just had a new furnace and air conditioner installed and the furnace has a variable speed motor, which means the fan is always on, taking air from the entire house and essentially recirculating it to eliminate temperature fluctuations.
I have a furnace with a variable speed motor, but it does not run all the time. I can set it to run all the time by a setting on the thermostat. In any case, I agree that you should try to keep radon levels below the recommended maximum.
You can buy an electronic radon gas detector so you can test multiple locations under various conditions without sending a kit into a lab for each test.

+1
When we had one, I set the fan to always on in the summer (with A/C) during the day, and on auto otherwise. Didn't see the point of it while asleep and didn't like the breeze during the winter when the heater wasn't running.

jharkin · Post by **jharkin** » Mon Jun 17, 2019 8:16 am

Just put in a radon system... Even if you need an active system, they are not all that expensive - around $1000-1500 is typical and that's a rounding error on the purchase price of the house. They use maybe $0.25 worth of electricity a day to run.

My previous home tested at 3.0, I left it alone. New house tested at 12.1 and I have the radon contractor scheduled the day after closing.

jharkin · Post by **jharkin** » Mon Jun 17, 2019 8:19 am

mmcmonster wrote: ↑
Sun Jun 16, 2019 6:17 am
I'm surprised that your mortgage company allowed you to buy the home without having radon remediation addressed.

Where I am (North East PA), you have to get your Radon remediation done by someone licensed by the state. I bought a continuous radon detector with a built-in alarm from amazon ( https://www.amazon.com/gp/product/B000C ... UTF8&psc=1 ). It correlated quite closely with the professional checks we had done.

Both the testing and mortgage issues you mention must be PA specific (Not surprised as I have read PA has some of the highest radon levels in the country). In MA there is no such requirements and mortgage companies dont even look at home inspection reports. Radon testing is optional and if you request it is something home inspectors do. Mortgage company, insurance companies and even the realtor have nothing to do with it.

mtmingus · Post by **mtmingus** » Mon Jun 17, 2019 8:44 am

Curious if these are two most popular potable radon detectors people use:

Corentium Home Radon Detector by Airthings 223 Portable
Safety Siren Pro Series3 Radon Gas Detector - HS71512 by Family Safety Products

Can you share your experiences with them on pitfalls /issues/recommendations?

Thanks!

bhsince87 · Post by **bhsince87** » Mon Jun 17, 2019 1:40 pm

mtmingus wrote: ↑
Mon Jun 17, 2019 8:44 am
Curious if these are two most popular potable radon detectors people use:

Corentium Home Radon Detector by Airthings 223 Portable
Safety Siren Pro Series3 Radon Gas Detector - HS71512 by Family Safety Products

Can you share your experiences with them on pitfalls /issues/recommendations?

Thanks!

I have an airthings Wave. It's $20 more, but I thought it was worth it for the app and the ability to plot humidity and temperature as well as radon.

The "wave" function is sort of silly, IMO. You wave your hand in front of it and it will flash red/green/or yellow depending on current radon levels. I just use the app instead.

I've been very happy with it. The app and the unit were both a bit buggy at first, but the company definitely improved it over time. I think I'm on my 4th firmware update. Also, the lithium battery didn't last nearly as long as they claimed it would. But I can live with that.

jayk238 · Post by **jayk238** » Mon Jun 17, 2019 1:59 pm

Call_Me_Op wrote: ↑
Sun Jun 16, 2019 6:36 am
The 4 pCi/L EPA action limit is arbitrary. This is equivalent to something like 200 chest x-rays per year. Unless you believe this is all hype, there is no proven safe level for ionizing radiation - it is a statistical "game." I would rather minimize any exposure above the unavoidable background.

As a doctor and public health grad this is the right answer.

If you look at the data most of it is extrapolated downward from high exposures in the past. We dont know what a safe level is and have no data to show how many cancers >4pCi causes. Simply that it seems like its not ideal.

The epa actually recommends <2 which is what we aim for.

You cannot get accurate reads from 48 hrs.

Research shows an average over months is best which is why we have a professional grade radon detector that continuously monitors.

I dont care about cost as long as I can meet my savings goals.

Feb29 · Post by **Feb29** » Mon Jun 17, 2019 2:01 pm

Our basement had a radon reading of just over 4.0. I got a radon remediation guy to install a system for $1000. Our reading went down to 0.7. I now have no worries about being in the basement or any other part of the house.

mtmingus · Post by **mtmingus** » Tue Jun 18, 2019 12:32 pm

bhsince87 wrote: ↑
Mon Jun 17, 2019 1:40 pm

mtmingus wrote: ↑
Mon Jun 17, 2019 8:44 am
Curious if these are two most popular potable radon detectors people use:

Corentium Home Radon Detector by Airthings 223 Portable
Safety Siren Pro Series3 Radon Gas Detector - HS71512 by Family Safety Products

Can you share your experiences with them on pitfalls /issues/recommendations?

Thanks!
I have an airthings Wave. It's $20 more, but I thought it was worth it for the app and the ability to plot humidity and temperature as well as radon.

The "wave" function is sort of silly, IMO. You wave your hand in front of it and it will flash red/green/or yellow depending on current radon levels. I just use the app instead.

I've been very happy with it. The app and the unit were both a bit buggy at first, but the company definitely improved it over time. I think I'm on my 4th firmware update. Also, the lithium battery didn't last nearly as long as they claimed it would. But I can live with that.

Do you need to purchased new battery and how much or the Wave once awhile?

Glockenspiel · Post by **Glockenspiel** » Tue Jun 18, 2019 12:43 pm

My radon level was around 7.0 pCi/L in my basement. We had an active fan installed in our attic. This pulled radon through a pipe (already installed in the house), from under the basement slab, through a vent out the roof. This installation only cost us $175, in 2013. After the installation of the fan, our basement radon level was around 0.3 pCi/L.

Very cheap insurance, especially if there's already a vent pipe connected to the draintile along the inside of your basement foundation.

bhsince87 · Post by **bhsince87** » Tue Jun 18, 2019 2:25 pm

mtmingus wrote: ↑
Tue Jun 18, 2019 12:32 pm

bhsince87 wrote: ↑
Mon Jun 17, 2019 1:40 pm

mtmingus wrote: ↑
Mon Jun 17, 2019 8:44 am
Curious if these are two most popular potable radon detectors people use:

Corentium Home Radon Detector by Airthings 223 Portable
Safety Siren Pro Series3 Radon Gas Detector - HS71512 by Family Safety Products

Can you share your experiences with them on pitfalls /issues/recommendations?

Thanks!
I have an airthings Wave. It's $20 more, but I thought it was worth it for the app and the ability to plot humidity and temperature as well as radon.

The "wave" function is sort of silly, IMO. You wave your hand in front of it and it will flash red/green/or yellow depending on current radon levels. I just use the app instead.

I've been very happy with it. The app and the unit were both a bit buggy at first, but the company definitely improved it over time. I think I'm on my 4th firmware update. Also, the lithium battery didn't last nearly as long as they claimed it would. But I can live with that.
Do you need to purchased new battery and how much or the Wave once awhile?

It came with a lithium AA's which lasted about a year and a half. I'm using standard alkaline AAs now, and it's gone about 6 months so far on them.

iamlucky13 · Post by **iamlucky13** » Tue Jun 18, 2019 4:52 pm

jayk238 wrote: ↑
Mon Jun 17, 2019 1:59 pm

Call_Me_Op wrote: ↑
Sun Jun 16, 2019 6:36 am
The 4 pCi/L EPA action limit is arbitrary. This is equivalent to something like 200 chest x-rays per year. Unless you believe this is all hype, there is no proven safe level for ionizing radiation - it is a statistical "game." I would rather minimize any exposure above the unavoidable background.
As a doctor and public health grad this is the right answer.

If you look at the data most of it is extrapolated downward from high exposures in the past. We dont know what a safe level is and have no data to show how many cancers >4pCi causes. Simply that it seems like its not ideal.

The epa actually recommends <2 which is what we aim for.

You cannot get accurate reads from 48 hrs.

Research shows an average over months is best which is why we have a professional grade radon detector that continuously monitors.

I dont care about cost as long as I can meet my savings goals.

The level is not arbitrary. It was based on an assessment of being reasonably achievable based on a cost of lives saved (source), similar to how clean water regulations, car safety regulations, and product recall determinations are made.

The data based on high exposure cases (mainly occupational exposure from before the hazard was well understood, such as for miners) is extrapolated downwards for below 4 pCi/L. Because of the difficulty getting statistically significant data for low frequency exposures giving all the confounding factors, the linear no-threshold assumption is used, so theoretically, if you get your levels down from 4 to 2 pCi/L, you cut your risk in half (neglecting adjustment for time spent outside the home). There's actually some hints the linear no threshold assumption may be conservative, but not many people are troubled by being conservative on such matters.

4 pCi/L occupational exposure (2000 hours / year) would be about 1 mSv. Round-the-clock exposure would be about 4 mSv.

A digital chest x-ray is 0.1 mSv, so the comparison is 10 to 40 chest x-rays. A CT scan is 10 mSv

Normal natural background radiation exposure averages 6.2 mSv, roughly 1/3 of which is from radon and thoron, but with significant regional variation.

I do agree that the cost of a mitigation system is pretty reasonable if you have levels anywhere close to the recommended action level and have some discretionary income.

megabad · Post by **megabad** » Tue Jun 18, 2019 5:08 pm

Glockenspiel wrote: ↑
Tue Jun 18, 2019 12:43 pm
My radon level was around 7.0 pCi/L in my basement. We had an active fan installed in our attic. This pulled radon through a pipe (already installed in the house), from under the basement slab, through a vent out the roof. This installation only cost us $175, in 2013. After the installation of the fan, our basement radon level was around 0.3 pCi/L.

Very cheap insurance, especially if there's already a vent pipe connected to the draintile along the inside of your basement foundation.

This. Don't know why people make things complicated. Get a fan. Done.

Mitchell777 · Post by **Mitchell777** » Wed Jun 19, 2019 3:06 pm

Are there potential risks associated with radon mitigation? For example, could you get water in your basement from drilling. I''m not suggesting it should not be done. Just asking a question.

rkhusky · Post by **rkhusky** » Thu Jun 20, 2019 7:19 am

Mitchell777 wrote: ↑
Wed Jun 19, 2019 3:06 pm
Are there potential risks associated with radon mitigation? For example, could you get water in your basement from drilling. I''m not suggesting it should not be done. Just asking a question.

Not if done properly. There are a number of problems that could arise, if done improperly, depending on the configuration of the system.

Isabelle77 · Post by **Isabelle77** » Thu Jun 20, 2019 8:25 am

I just assume that all basements in the NE have radon so I'm just planning on getting a remediation system without testing first. Does that make sense or does the radon company need numbers to know what to do?

testing321 · Post by **testing321** » Thu Jun 20, 2019 10:44 am

You might be able to reduce radon levels by caulking any cracks in the basement floor. I used a clear silicone caulk.

mmmodem · Post by **mmmodem** » Thu Jun 20, 2019 11:58 am

Isabelle77 wrote: ↑
Thu Jun 20, 2019 8:25 am
Not to hijack the thread but after bidding wars and losing two homes in MA we waived the radon test in the house that we're buying. I just assume that all basements in the NE have radon so I'm just planning on getting a remediation system without testing first. Does that make sense or does the radon company need numbers to know what to do?

It's some $1500-$3000 for a simple remediation. Yes, I would agree waiving it is no big deal on your end in relative to the home price. However, I don't know if waiving just the radon contingency makes your bid look better. Waiving all contingencies would.

Isabelle77 · Post by **Isabelle77** » Thu Jun 20, 2019 12:27 pm

mmmodem wrote: ↑
Thu Jun 20, 2019 11:58 am

Isabelle77 wrote: ↑
Thu Jun 20, 2019 8:25 am
Not to hijack the thread but after bidding wars and losing two homes in MA we waived the radon test in the house that we're buying. I just assume that all basements in the NE have radon so I'm just planning on getting a remediation system without testing first. Does that make sense or does the radon company need numbers to know what to do?
It's some $1500-$3000 for a simple remediation. Yes, I would agree waiving it is no big deal on your end in relative to the home price. However, I don't know if waiving just the radon contingency makes your bid look better. Waiving all contingencies would.

We did get this house, thank goodness.

hicabob · Post by **hicabob** » Thu Jun 20, 2019 12:28 pm

Mitchell777 wrote: ↑
Wed Jun 19, 2019 3:06 pm
Are there potential risks associated with radon mitigation? For example, could you get water in your basement from drilling. I''m not suggesting it should not be done. Just asking a question.

The sub-floor depressurization actually removes large amounts of moisture from under the slab. The fans are powerful.

rkhusky · Post by **rkhusky** » Thu Jun 20, 2019 9:11 pm

mmmodem wrote: ↑
Thu Jun 20, 2019 11:58 am

Isabelle77 wrote: ↑
Thu Jun 20, 2019 8:25 am
Not to hijack the thread but after bidding wars and losing two homes in MA we waived the radon test in the house that we're buying. I just assume that all basements in the NE have radon so I'm just planning on getting a remediation system without testing first. Does that make sense or does the radon company need numbers to know what to do?
It's some $1500-$3000 for a simple remediation. Yes, I would agree waiving it is no big deal on your end in relative to the home price. However, I don't know if waiving just the radon contingency makes your bid look better. Waiving all contingencies would.

We got a sump pump system with pipe exiting the basement and then up and around the gutters for about $800. They sealed a sheet of lexan over the sump pump pit so you could see what was going on with the pump and water level.

IMO · Post by **IMO** » Thu Jun 20, 2019 10:09 pm

plannerman wrote: ↑
Sun Jun 16, 2019 5:59 am
Here radon tests are pretty much a standard part of home inspections. When you eventually want to sell your house, you will probably have to remediate the radon to sell it--regardless of whether it's a significant health hazard or not. You might as well do it now and get it over-with.

plannerman

Are radon tests standard for home inspections in other parts, such as Southwest/West Coast?

In these areas, basements are NOT common. If one did test for radon and it was high, how does one mitigate radon with concrete slab foundations?

Also, are public buildings and/or places of employment required to test for radon levels and mitigate any high levels so as to not cause excessive exposure while one is at work?

https://www.google.com/url?sa=i&source= ... 2650583239

jaybee9 · Post by **jaybee9** » Thu Jun 20, 2019 10:17 pm

mtmingus wrote: ↑
Mon Jun 17, 2019 8:44 am
Curious if these are two most popular potable radon detectors people use:

Corentium Home Radon Detector by Airthings 223 Portable
Safety Siren Pro Series3 Radon Gas Detector - HS71512 by Family Safety Products

Can you share your experiences with them on pitfalls /issues/recommendations?

Thanks!

I have had the Corentium Home Detector for several years now. I leave it down in our basement. It works well, gives short and long term readings. Battery lasts usually over a year I think.

Call_Me_Op · Post by **Call_Me_Op** » Fri Jun 21, 2019 7:00 am

iamlucky13 wrote: ↑
Tue Jun 18, 2019 4:52 pm

jayk238 wrote: ↑
Mon Jun 17, 2019 1:59 pm

Call_Me_Op wrote: ↑
Sun Jun 16, 2019 6:36 am
The 4 pCi/L EPA action limit is arbitrary. This is equivalent to something like 200 chest x-rays per year. Unless you believe this is all hype, there is no proven safe level for ionizing radiation - it is a statistical "game." I would rather minimize any exposure above the unavoidable background.
As a doctor and public health grad this is the right answer.

If you look at the data most of it is extrapolated downward from high exposures in the past. We dont know what a safe level is and have no data to show how many cancers >4pCi causes. Simply that it seems like its not ideal.

The epa actually recommends <2 which is what we aim for.

You cannot get accurate reads from 48 hrs.

Research shows an average over months is best which is why we have a professional grade radon detector that continuously monitors.

I dont care about cost as long as I can meet my savings goals.
The level is not arbitrary. It was based on an assessment of being reasonably achievable based on a cost of lives saved (source), similar to how clean water regulations, car safety regulations, and product recall determinations are made.

The data based on high exposure cases (mainly occupational exposure from before the hazard was well understood, such as for miners) is extrapolated downwards for below 4 pCi/L. Because of the difficulty getting statistically significant data for low frequency exposures giving all the confounding factors, the linear no-threshold assumption is used, so theoretically, if you get your levels down from 4 to 2 pCi/L, you cut your risk in half (neglecting adjustment for time spent outside the home). There's actually some hints the linear no threshold assumption may be conservative, but not many people are troubled by being conservative on such matters.

4 pCi/L occupational exposure (2000 hours / year) would be about 1 mSv. Round-the-clock exposure would be about 4 mSv.

A digital chest x-ray is 0.1 mSv, so the comparison is 10 to 40 chest x-rays. A CT scan is 10 mSv

Normal natural background radiation exposure averages 6.2 mSv, roughly 1/3 of which is from radon and thoron, but with significant regional variation.

I do agree that the cost of a mitigation system is pretty reasonable if you have levels anywhere close to the recommended action level and have some discretionary income.

Estimated dose for chest xrays varies depending upon type of machine and other factors. See reference below, for example, that specifies an EED of 0.01 msV to 0.02 msV, which would equate 4 pCi/L to as high as 200 to 400 chest xrays. Perhaps this is a minor point. I think we agree that it is not worth taking this risk, which is generally easy to mitigate.

https://bmjopen.bmj.com/content/bmjopen ... 8.full.pdf

When i say that 4 pCi/L is arbitrary, I am speaking from the health effects standpoint. There is nothing magic that happens at 4. If you get it down to 2, you have probably reduced your risk of lung cancer, and 1 is probably better than 2.

jayk238 · Post by **jayk238** » Fri Jun 21, 2019 10:14 am

iamlucky13 wrote: ↑
Tue Jun 18, 2019 4:52 pm

jayk238 wrote: ↑
Mon Jun 17, 2019 1:59 pm

Call_Me_Op wrote: ↑
Sun Jun 16, 2019 6:36 am
The 4 pCi/L EPA action limit is arbitrary. This is equivalent to something like 200 chest x-rays per year. Unless you believe this is all hype, there is no proven safe level for ionizing radiation - it is a statistical "game." I would rather minimize any exposure above the unavoidable background.
As a doctor and public health grad this is the right answer.

If you look at the data most of it is extrapolated downward from high exposures in the past. We dont know what a safe level is and have no data to show how many cancers >4pCi causes. Simply that it seems like its not ideal.

The epa actually recommends <2 which is what we aim for.

You cannot get accurate reads from 48 hrs.

Research shows an average over months is best which is why we have a professional grade radon detector that continuously monitors.

I dont care about cost as long as I can meet my savings goals.
The level is not arbitrary. It was based on an assessment of being reasonably achievable based on a cost of lives saved (source), similar to how clean water regulations, car safety regulations, and product recall determinations are made.

The data based on high exposure cases (mainly occupational exposure from before the hazard was well understood, such as for miners) is extrapolated downwards for below 4 pCi/L. Because of the difficulty getting statistically significant data for low frequency exposures giving all the confounding factors, the linear no-threshold assumption is used, so theoretically, if you get your levels down from 4 to 2 pCi/L, you cut your risk in half (neglecting adjustment for time spent outside the home). There's actually some hints the linear no threshold assumption may be conservative, but not many people are troubled by being conservative on such matters.

4 pCi/L occupational exposure (2000 hours / year) would be about 1 mSv. Round-the-clock exposure would be about 4 mSv.

A digital chest x-ray is 0.1 mSv, so the comparison is 10 to 40 chest x-rays. A CT scan is 10 mSv

Normal natural background radiation exposure averages 6.2 mSv, roughly 1/3 of which is from radon and thoron, but with significant regional variation.

I do agree that the cost of a mitigation system is pretty reasonable if you have levels anywhere close to the recommended action level and have some discretionary income.

You are misunderstanding me and proving my point again. There is data, i agree. But the data is based on high exposure rates in miners and extrapolated down. Its the same thing YOU said. We are extrapolating. Its not out of thin air but it is never the less an estimate. Obviously its reasonable hence why i have a radon mitigation system and aim for <2.

Ironically your comparison to msv for xrays is also similarily misguided. We actually dont know the exsct cancer risk from this low a radiation from imaging. This too is based on radiation risk by statistically extrapolating from high exposures.

Alf 101 · Post by **Alf 101** » Fri Jun 21, 2019 11:52 am

When we moved into our previous home, the 48 hour test revealed basement levels of 4.2 pCi/L. Since it was the basement, and no bedrooms were down there, we weren't overly concerned -- the basement had two sump pumps, after all. We did, however, purchase a kit to run a one-year test, through our state Department of Health. This came back with an average level around or less than 3.0.

We provided this information when we sold the house, after the buyer's inspection pulled a reading just over 4.0 pCi/L too. Unfortunately, some people are a little more worried about low levels of radiation than others, or unfamiliar with the linear no-threshold concept. The buyer nearly pulled out, though may have felt foolish upon realizing every other house would consider likely have readings in that range or higher. It was a full-price offer, and in the end we saved the deal by putting in a radon mitigation system, which was somewhere around $1K.

If you're concerned, and someday may sell the house, this is something to look into. Our basement may have been a particularly easy set-up, but it should not be prohibitive -- $1500-3000 was quoted, which will vary according to where you are in the country, and how much hiring anyone generally costs. I don't see great hazard here, but if it gives you peace of mind, you may consider it.

TomatoTomahto · Post by **TomatoTomahto** » Fri Jun 21, 2019 12:07 pm

Would placement of a sensor in a utility room be okay, or should it be in a room that is frequently occupied? We have a walkout basement, and the utility room is mostly below grade.

hicabob · Post by **hicabob** » Sat Jun 22, 2019 10:32 am

TomatoTomahto wrote: ↑
Fri Jun 21, 2019 12:07 pm
Would placement of a sensor in a utility room be okay, or should it be in a room that is frequently occupied? We have a walkout basement, and the utility room is mostly below grade.

A "closed" house will have the highest readings since no fresh air from windows/doors will dilute the radon. A room in the basement that is closed off from the rest of the house will probably have higher readings. Since the object is to ascertain human exposure I would think the monitor in a living area is more representative.

This 4 part youtube series on radon is quite interesting and claims the scare is overblown.
https://www.youtube.com/watch?v=TYZglUjLE0Y

rkhusky · Post by **rkhusky** » Sat Jun 22, 2019 11:08 am

hicabob wrote: ↑
Sat Jun 22, 2019 10:32 am
A "closed" house will have the highest readings since no fresh air from windows/doors will dilute the radon.

Is this necessarily true? Seems like it would depend on the outside temperature - i.e. if it is cold outside, then opening a window upstairs would cause warmer air to flow out of the house creating additional pressure to suck more radon into the lower parts of the house. Seems like the natural rising of warm air would cause radon to be sucked into the basement and up through the rest of the house.

adamthesmythe · Post by **adamthesmythe** » Sat Jun 22, 2019 12:52 pm

rkhusky wrote: ↑
Sat Jun 22, 2019 11:08 am

hicabob wrote: ↑
Sat Jun 22, 2019 10:32 am
A "closed" house will have the highest readings since no fresh air from windows/doors will dilute the radon.
Is this necessarily true? Seems like it would depend on the outside temperature - i.e. if it is cold outside, then opening a window upstairs would cause warmer air to flow out of the house creating additional pressure to suck more radon into the lower parts of the house. Seems like the natural rising of warm air would cause radon to be sucked into the basement and up through the rest of the house.

I think it very unlikely that the radon concentration will increase with increased ventilation. Probably the flux of radon into the basement is roughly a constant. Anything to exchange air will tend to decrease the concentration.

It's worth noting that radon is a great deal heavier than air, and as a result will tend to accumulate in the basement.

rkhusky · Post by **rkhusky** » Sat Jun 22, 2019 2:22 pm

adamthesmythe wrote: ↑
Sat Jun 22, 2019 12:52 pm
It's worth noting that radon is a great deal heavier than air, and as a result will tend to accumulate in the basement.

Not what I've heard. If true, why does it enter the house from the ground?

rkhusky · Post by **rkhusky** » Sun Jun 23, 2019 6:42 am

rkhusky wrote: ↑
Sat Jun 22, 2019 2:22 pm

adamthesmythe wrote: ↑
Sat Jun 22, 2019 12:52 pm
It's worth noting that radon is a great deal heavier than air, and as a result will tend to accumulate in the basement.
Not what I've heard. If true, why does it enter the house from the ground?

In thinking about this some more, there are probably a number of effects happening. One is the tendency for gases and liquids to diffuse. There is an induced pressure when the concentrations of liquids and gases in different regions are not equal. When a semipermeable membrane separates the regions it is called osmotic pressure. This is what probably causes the radon gas to move through the soil, into the house, and then throughout the house. The diffusion throughout the house is aided by movement of the air, including that caused by convection (warm air rising) and the HVAC system.

CWRadio · Post by **CWRadio** » Sun Jun 23, 2019 7:41 am

A little off subject. My house is 15 years old and has a passive Radon mitigation system (no fan) connected to the sump.
When the house was built the radon level was 1 and now it is 3.9. I plan on adding a passive mitigation fan to the 3 inch PVC pipe in the attic.
My question is how do you determine the correct passive mitigation fan speed?
I plan on hiring a Radon certified technician to install the unit, but being a retired engineer I would like to understand the calculation for the correct fan speed.
Thanks Paul

BHUser27 · Post by **BHUser27** » Sun Jun 23, 2019 8:10 am

CWRadio wrote: ↑
Sun Jun 23, 2019 7:41 am
A little off subject. My house is 15 years old and has a passive Radon mitigation system (no fan) connected to the sump.
When the house was built the radon level was 1 and now it is 3.9. I plan on adding a passive mitigation fan to the 3 inch PVC pipe in the attic.
My question is how do you determine the correct passive mitigation fan speed?
I plan on hiring a Radon certified technician to install the unit, but being a retired engineer I would like to understand the calculation for the correct fan speed.
Thanks Paul

Hi Paul -
As far as I know the in-line Radon mitigation fans are sized by the amount of suction your install requires, and is a pretty rough guess based on soil porosity and how the evacuation is done (via drain tile, sump well, under-slab, etc.

Maybe this article will help? https://www.americanradonmitigation.com ... radon-fan/

rkhusky · Post by **rkhusky** » Sun Jun 23, 2019 9:19 am

CWRadio wrote: ↑
Sun Jun 23, 2019 7:41 am
A little off subject. My house is 15 years old and has a passive Radon mitigation system (no fan) connected to the sump.
When the house was built the radon level was 1 and now it is 3.9. I plan on adding a passive mitigation fan to the 3 inch PVC pipe in the attic.
My question is how do you determine the correct passive mitigation fan speed?
I plan on hiring a Radon certified technician to install the unit, but being a retired engineer I would like to understand the calculation for the correct fan speed.
Thanks Paul

Minor point, but when you add a fan, it is no longer passive mitigation, it is active.

Also, the passive system works best in the winter when the air temperature differential is greatest. So, you might want to test over a variety of outside conditions, or do a long term test to get an average over many outside conditions.

hicabob · Post by **hicabob** » Sun Jun 23, 2019 9:40 am

rkhusky wrote: ↑
Sat Jun 22, 2019 2:22 pm

adamthesmythe wrote: ↑
Sat Jun 22, 2019 12:52 pm
It's worth noting that radon is a great deal heavier than air, and as a result will tend to accumulate in the basement.
Not what I've heard. If true, why does it enter the house from the ground?

Boyle's law would like a word with you. If you put a gas in a container it will fill it ....
"One of the properties of gases is that they mix with each other. When they do so, they become a solution—a homogeneous mixture."

hicabob · Post by **hicabob** » Sun Jun 23, 2019 9:59 am

rkhusky wrote: ↑
Sun Jun 23, 2019 9:19 am

CWRadio wrote: ↑
Sun Jun 23, 2019 7:41 am
A little off subject. My house is 15 years old and has a passive Radon mitigation system (no fan) connected to the sump.
When the house was built the radon level was 1 and now it is 3.9. I plan on adding a passive mitigation fan to the 3 inch PVC pipe in the attic.
My question is how do you determine the correct passive mitigation fan speed?
I plan on hiring a Radon certified technician to install the unit, but being a retired engineer I would like to understand the calculation for the correct fan speed.
Thanks Paul
Minor point, but when you add a fan, it is no longer passive mitigation, it is active.

Also, the passive system works best in the winter when the air temperature differential is greatest. So, you might want to test over a variety of outside conditions, or do a long term test to get an average over many outside conditions.

Fan power will depend on the under slab material and size of area you are trying to depressurize. A mostly pea gravel underslab layer will be easier to suck air thru than a sand/gravel mix so require a smaller fan to get the same air flow rate. A huge slab requires more suction than a little one.

adamthesmythe · Post by **adamthesmythe** » Sun Jun 23, 2019 11:59 am

hicabob wrote: ↑
Sun Jun 23, 2019 9:40 am

rkhusky wrote: ↑
Sat Jun 22, 2019 2:22 pm

adamthesmythe wrote: ↑
Sat Jun 22, 2019 12:52 pm
It's worth noting that radon is a great deal heavier than air, and as a result will tend to accumulate in the basement.
Not what I've heard. If true, why does it enter the house from the ground?
Boyle's law would like a word with you. If you put a gas in a container it will fill it ....
"One of the properties of gases is that they mix with each other. When they do so, they become a solution—a homogeneous mixture."

Umm, no. You are not accounting for gravity.

This is a classic problem in statistical mechanics. The gas density is larger toward the bottom of a column. And the effect depends on the molecular mass.