radon mitigation exposure concern, are we at risk?

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jayk238
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radon mitigation exposure concern, are we at risk?

Post by jayk238 » Mon Aug 06, 2018 8:29 pm

We are renting a home and about say 50 yards from us is another home with a radon mitigation system- basically a PVC pipe that is about 16 to 20 feet above and venting out radon.

Is this safe for us? Its a bit unnerving because the pipe opening is facing us but obviously its closest to them.

What concerns me is that I never see that family outside and am wondering if its due to this

I know radon is outside everywhere but wondering if we are being exposed to higher levels sitting on our deck so close to them

This home itself doesnt have a basement, although I know the EPA says it can happen anywhere.

I plan to buy a radon testing kit just for this place

We will only rent here for a year but you never can be too careful

TBillT
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Re: radon mitigation exposure concern, are we at risk?

Post by TBillT » Mon Aug 06, 2018 8:32 pm

You are probably not at any risk from your neighbors house.
The implication however is that your house may also have a radon problem.

The radon is natural coming from the earth. By the time you are outside you are breathing diluted air.

FIREmeup
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Re: radon mitigation exposure concern, are we at risk?

Post by FIREmeup » Mon Aug 06, 2018 9:59 pm

We have a radon mitigation system. We have a basement and the reading there was just below the lower bound of danger zone but we opted for the system anyway. The room on the first floor above the basement had a 0 reading before the mitigation.

You have zero risk from your neighbor's system.

https://iaq.zendesk.com/hc/en-us/articl ... _site=true

I would get your areas tested...good to know and worst ways to spend $50 or $60. If you have no basement the risk of danger is limited.

tim1999
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Re: radon mitigation exposure concern, are we at risk?

Post by tim1999 » Tue Aug 07, 2018 5:42 am

Don’t stick your face in the opening of the neighbor’s pipe for extended periods of time and you will be fine.

mmmodem
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Re: radon mitigation exposure concern, are we at risk?

Post by mmmodem » Tue Aug 07, 2018 7:17 am

There is no safe level of radon. The EPA came up with a number for when remediation is necessary at 4.0 pCi/L but it doesn't mean 3.9 is safe. I'm not an expert, just a homeowner that did a lot circumspect internet research. Take what I say with a grain of salt and do your own research.

You already understand that radon is everywhere. You also have to understand that energy efficient homes especially ones with basements tend to have negative air pressure. That is, air is sucked into the home. Radon as a gas is sucked into the home and it concentrates in the home. At higher concentrations is where it radon becomes a big issue.

That means even if you stick your head and breathe in the exhaust, you're not necessarily getting more radon than if you were sitting on the front porch. You may if the system hasn't been running continuously so that radon built up in the home like after a black out. If it has been running continuously, it's just getting rid of ambient radon so that it doesn't collect in the home. Perhaps even the same ambient radon you would breathe in on your front porch.

Should you be concerned? Maybe. Two homes next each other may have drastically different radon levels if one of the homes just happens to sit on a high concentrations of radon.

I just bought a home that was tested at 3.6 pCi/L average. I was annoyed by this test as the chart clearly shows that radon peaks above 4 quite often on the chart. However, because the average is below 4, I had no grounds to ask the sellers for concessions on remediation. I've since purchased a battery operated home radon test device and have noticed how a basement window can increase or decrease radon levels drastically. I didn't bother with the one time only lab kits. I bought a $150 device that I can take with me to my next home.

Nate79
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Re: radon mitigation exposure concern, are we at risk?

Post by Nate79 » Tue Aug 07, 2018 7:24 am

tim1999 wrote:
Tue Aug 07, 2018 5:42 am
Don’t stick your face in the opening of the neighbor’s pipe for extended periods of time and you will be fine.
Radon vaping.

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Re: radon mitigation exposure concern, are we at risk?

Post by Call_Me_Op » Tue Aug 07, 2018 7:25 am

Radon only reaches high levels when it accumulates in a home with poor ventilation. The outdoors is well ventilated.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

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Re: radon mitigation exposure concern, are we at risk?

Post by iamlucky13 » Tue Aug 07, 2018 1:50 pm

Your neighbor's mitigation system should not be a concern outdoors. The traces it ventilates from the home prevent accumulation in the enclosed space, which is the concern. Once outside his home, it disperses into a far, far larger volume of air.
mmmodem wrote:
Tue Aug 07, 2018 7:17 am
There is no safe level of radon. The EPA came up with a number for when remediation is necessary at 4.0 pCi/L but it doesn't mean 3.9 is safe. I'm not an expert, just a homeowner that did a lot circumspect internet research. Take what I say with a grain of salt and do your own research.
The most accurate way to state this is there is no known safe level. The effects of radioactive exposure at low levels are difficult to determine, so the conservative assumption is to extrapolate from levels of known harm based on what is known as the linear no threshold model - eg, if you halve the dose, you halve the risk. Some research suggests there may be a more pronounced declines at low doses, but the results are hazy because there's a very low signal to noise ratio, and it varies by type of exposure.

The action level for indoor air of 4 pico Curies per Liter (pCi/L) presents a lung cancer risk that is detectable in large epidemiological studies. The research establishing this is a bit complex, but taken as a whole, do indicate levels in the ballpark of 4 pCi/L present a small but actual rather than theoretically extrapolated risk.

What the research doesn't seem to be able to answer so far is whether that risk extends proportionately to lower levels. I personally would treat 3.9 pCi/L as close enough to 4 pCi/L to expect proportionate risks, but it's hard to say if 2 pCi/L is half as bad, like the linear no threshold model assumes.

To get back on track to the OP's concern, if your neighbor has a mitigation system, the consideration I think you should focus on is not whether his system affects the outdoor air near you, but whether you should also have a mitigation system for your own indoor air. If you have not, I would have your home's radon levels tested.

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Epsilon Delta
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Re: radon mitigation exposure concern, are we at risk?

Post by Epsilon Delta » Tue Aug 07, 2018 4:49 pm

tim1999 wrote:
Tue Aug 07, 2018 5:42 am
Don’t stick your face in the opening of the neighbor’s pipe for extended periods of time and you will be fine.
The biggest danger of stick your face in the opening of the neighbor’s pipe for extended periods of time is your neighbor’s shotgun or your neighbor’s sarcasm.

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Re: radon mitigation exposure concern, are we at risk?

Post by dcdowden » Tue Aug 07, 2018 5:08 pm

mmmodem wrote:
Tue Aug 07, 2018 7:17 am

I just bought a home that was tested at 3.6 pCi/L average. I was annoyed by this test as the chart clearly shows that radon peaks above 4 quite often on the chart. However, because the average is below 4, I had no grounds to ask the sellers for concessions on remediation. I've since purchased a battery operated home radon test device and have noticed how a basement window can increase or decrease radon levels drastically. I didn't bother with the one time only lab kits. I bought a $150 device that I can take with me to my next home.
What kind of kit did you buy? I have bought the 1 shot lab kits before for others, but this sounds better if it is accurate. What's your view?

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ClevrChico
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Re: radon mitigation exposure concern, are we at risk?

Post by ClevrChico » Tue Aug 07, 2018 10:23 pm

I live in the highest radon area in the US, and this situation is common and I see no danger. The air coming out of the pipe is comprised mostly of indoor air from the neighbor's house with a tiny concentration of radon. It's no different than walking outside in a park.

There would only be a problem in the air was somehow being pumped back into the house through a window. And then it would just be nullifying the benefit of the system, it's not like it's poison gas. :-)

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grayfox
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Re: radon mitigation exposure concern, are we at risk?

Post by grayfox » Wed Aug 08, 2018 12:46 am

What about other sources of radiation?

According to this article, 8 Foods You Didn't Know Are Radioactive

Bananas have 3,520 pCi/kg
Potatoes 4,500 pCi/kg
Carrots 6,800 pCi/kg
Lima Beans 4,630 pCi/kg
Red Meat 3,000 pCi/kg
Low-Sodium Salt 3,000 pCi/kg
Beer 390 pCi/kg
Brazil Nuts 6,600 pCi/kg

These numbers appear like 1,000x higher than radon limit of 4 pCi/kg and we are ingesting them.

Then there is this chart: How much radiation do you absorb doing everyday tasks?

You get 40 uSv flying in a plane across the country. We are exposed to ionizing radiation from stone, brick or concrete buildings that we live in, from our fancy granite countertops, from the food we eat (Potassium-40), from our friends, neighbors, family members and pets (Carbon-14) and on and on.

:idea: To me it seems irrational to worry only about radon gas, spending money mitigating it,while ignoring the numerous other sources of ionizing radiation in our daily lives.

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Re: radon mitigation exposure concern, are we at risk?

Post by Call_Me_Op » Wed Aug 08, 2018 8:31 am

grayfox wrote:
Wed Aug 08, 2018 12:46 am
What about other sources of radiation?

According to this article, 8 Foods You Didn't Know Are Radioactive

Bananas have 3,520 pCi/kg
Potatoes 4,500 pCi/kg
Carrots 6,800 pCi/kg
Lima Beans 4,630 pCi/kg
Red Meat 3,000 pCi/kg
Low-Sodium Salt 3,000 pCi/kg
Beer 390 pCi/kg
Brazil Nuts 6,600 pCi/kg

These numbers appear like 1,000x higher than radon limit of 4 pCi/kg and we are ingesting them.

Then there is this chart: How much radiation do you absorb doing everyday tasks?

You get 40 uSv flying in a plane across the country. We are exposed to ionizing radiation from stone, brick or concrete buildings that we live in, from our fancy granite countertops, from the food we eat (Potassium-40), from our friends, neighbors, family members and pets (Carbon-14) and on and on.

:idea: To me it seems irrational to worry only about radon gas, spending money mitigating it,while ignoring the numerous other sources of ionizing radiation in our daily lives.
The EPA limit for radon is 4 pCi/L, not PCi/kg.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

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Re: radon mitigation exposure concern, are we at risk?

Post by mmmodem » Wed Aug 08, 2018 8:47 am

dcdowden wrote:
Tue Aug 07, 2018 5:08 pm
What kind of kit did you buy? I have bought the 1 shot lab kits before for others, but this sounds better if it is accurate. What's your view?
I bought the Airthings Wave
https://smile.amazon.com/dp/B01MSEQYY9/ ... ABb4EBD4F4
It currently lists at $200 but often goes for $150. I watched it for 4 months and it dropped to that price twice before I bought it.

In terms of accuracy, the reviews on Amazon claim it is accurate to the send out lab kits. Take that for what it is worth. My anecdotal is that it matches up with what was measured by the inspector's test before we bought the home. Radon levels vary up to 3 pCi/L between day and night in my home according to the inspectors report and this device. So it's hard to say for sure if it is accurate but I am satisfied with the device's performance.

The reason I purchased this particular model is because it connects through bluetooth so I can monitor the levels without having to physically go down into the basement. It also measures humidity and temperature which is a nice bonus. I can also download every measurement so I can get a seasonal view of the radon levels. The device is completely portable. It comes with lithium AA batteries that supposedly lasts 1.5 years.

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grayfox
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Re: radon mitigation exposure concern, are we at risk?

Post by grayfox » Wed Aug 08, 2018 10:35 am

Here's a video where a scientist with a Geiger counter tests various things you have around the house. A Geiger counter measures ionizing radiation.

Brazil nuts from Brazil are radioactive, but Brazil nuts not from Brazil only 1-2 counts per second on the Geiger counter.
Low sodium salt contains K-40, 5-10 cps
Antique Glass bowl. Made from Uranium glass. 100 cps
Smoke Alarm. Americium 200-500 cps
Granite 500-1000 cps. Almost pegs the meter!

Then a tub of low-level nuclear waste. Only 10 cps! He couldn't actually have the real nuclear waste because its highly regulated, but only as radioactive as low-sodium salt that you find in the supermarket.

People have an irrational fear of radiation. To me, it is irrational to show great concern over 3.9 pCi/L radon, if you also put in granite countertops, or a brick fireplace built with radioactive bricks, or concrete walls or floors that were mixed with radioactive aggregate, or live on a high plateau in Colorado, or if you are a smoker or anyone in your house smokes.

:?: Why not test the granite countertops, concrete slabs, bricks etc. with a Geiger counter. If anything shows more than 10 cps, the amount for low-level nuclear waste, tear it out.

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tadamsmar
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Re: radon mitigation exposure concern, are we at risk?

Post by tadamsmar » Wed Aug 08, 2018 11:00 am

grayfox wrote:
Wed Aug 08, 2018 12:46 am
What about other sources of radiation?

According to this article, 8 Foods You Didn't Know Are Radioactive

Bananas have 3,520 pCi/kg
Potatoes 4,500 pCi/kg
Carrots 6,800 pCi/kg
Lima Beans 4,630 pCi/kg
Red Meat 3,000 pCi/kg
Low-Sodium Salt 3,000 pCi/kg
Beer 390 pCi/kg
Brazil Nuts 6,600 pCi/kg

These numbers appear like 1,000x higher than radon limit of 4 pCi/kg and we are ingesting them.
The radon limit is 4 pCi/liter. Liter of air, not kilogram.

We breathe about 11,000 liters per day.

"Radon is responsible for about 21,000 lung cancer deaths every year. About 2,900 of these deaths occur among people who have never smoked."

https://www.epa.gov/radon/health-risk-radon

Not that your neighbor's mitigation system is a concern.

Testing one's home with a cheap kit is recommended by the EPA, regardless of the location.

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tadamsmar
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Re: radon mitigation exposure concern, are we at risk?

Post by tadamsmar » Wed Aug 08, 2018 11:54 am

I have seen a strategy recommended where you buy a cheap kit first. Then, if the reading is between 2 and 8 pCi/L, you follow up with a more expensive test that is more accurate.

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grayfox
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Re: radon mitigation exposure concern, are we at risk?

Post by grayfox » Wed Aug 08, 2018 1:23 pm

A basic look at what Radon is: Radon - Periodic Table of Videos: https://youtu.be/mTuC_LrEfbU

Radon (Rn 86) is given off as a gas from the radioactive decay of Radium (Ra 88).
Radium-226 -> Radon-222 + α α particle is Helium nucleus He.2+

Radon is also radioactive and decays. Half life is 3.8 days. Radon Decay Chain:

Radon-222 -> Polonium-218 + α 3.8 days.
Polonium-218 -> Lead-214 + α 3.1 minutes
Lead-214 -> Bismuth-214 + β- 26.8 minutes
Bismuth-214 -> Polonium-214 + β- 19.9 minutes
Polonium-214 -> Lead-210 + α 0.2 sec
Lead-210 -> Bismuth-210 + β- 22.3 years
Bismuth-210 -> Polonium-210 5 days
Polonium-210 -> Lead-206 + α 138.4 days
Lead-206 stable

So you start with Radium-226 and eventually end up with Lead-206, which is a stable nucleus.
Last edited by grayfox on Wed Aug 08, 2018 3:20 pm, edited 5 times in total.

bhsince87
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Re: radon mitigation exposure concern, are we at risk?

Post by bhsince87 » Wed Aug 08, 2018 2:40 pm

I also have the Airthings Wave. I love it! It's nice to be able to move it around to different parts of the house.

I've always been concerned about radon gas coming up through our well water when we take a shower. I've read some studies that claimed that can be the biggest source in some areas. But the cheaper testers are well suited for that sort of test.

So i just sat this in the bathroom for a few months, and I never saw a rise during the shower.

I also like the data logging feature. It's amazing how variable the readings can be, mostly related to air pressure changes and time of year. I can also see the impact of opening a window or garage door.

It takes a few weeks to build accuracy, so i was a little concerned at first. but eventually it came down more in line with the mail-in tests.

I also had major issues running the app on on older android phone. It was listed as comapitable, but it was marginal. With a new phone, all issues went away.
Retirement: When you reach a point where you have enough. Or when you've had enough.

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grayfox
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Re: radon mitigation exposure concern, are we at risk?

Post by grayfox » Wed Aug 08, 2018 3:29 pm

Set of 4 videos from this guy who is an industrial hygienist and deals with human health hazards.

Radon 1 of 4: https://youtu.be/TYZglUjLE0Y

What is a Curie? 37x10^9 disintegrations per second. (initial decay rate of 1 gram of Radium)

What is a picoCurie (pCi)? pico is 10^-12, so 1 pC = 0.037 disintegrations per second. 4 pCi is 0.148 dis-integrations per second
A dis-integration is one decay event which emits one α particle, β- or γ radiation. Looking at the decay chain above, you can see that some dis-integrations are giving off α radiation and some β-

So the units pCi/L does not measure the concentration of Radon, but the amount of decay activity of all the elements (Ra, Po, Bi, Pb) in 1 liter of air.

A level 4 pCi/L of air means that there are 0.148 dis-integrations per second for each 1 liter of air. About one decay every 6.76 seconds.

EPA suggests a limit of 4 pCi/L (units are EPA pCi/L, which are a little different than regular pCi/L)
OSHA Permissible Exposure Limit = 100 pCi/L

Bananas 80,000 pCi/L
Milk 800-1200 pCi/L
Wine 400 to 800 pCi/L
Human Body: about 150 grams of K-40 (4,400 disintegrations per second)

The Wisdom of Paracelsus: The Dose makes the Poison

Hazard - the inherent ability to produce harm
Risk - the probability of that harm being realized

Radon 2 of 4: https://youtu.be/37pCurE0nxo

Safety - attaining an acceptable level of risk

27:52 Explanation of how EPA came up with Radon Dose-Risk Curve for Residential. (Linear No-Threshold Dose Response Curve)
Last edited by grayfox on Wed Aug 08, 2018 4:01 pm, edited 1 time in total.

jayk238
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Re: radon mitigation exposure concern, are we at risk?

Post by jayk238 » Wed Aug 08, 2018 3:36 pm

Thanks!

This is why i love this site.

Signal thru the noise.

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Re: radon mitigation exposure concern, are we at risk?

Post by iamlucky13 » Wed Aug 08, 2018 5:32 pm

Interestingly, I'm usually the person trying to calm exaggerated fears about radioactivity online. It's a complex topic most people don't understand at all, much less well, so many people default to a high level of concern.

However, radon has been demonstrated to be an actual risk. I refer to it above as a small risk in the grand scheme of things, but by small, I don't mean non-trivial. Radon is actually the largest component of our background radiation exposure, and it varies by region. In a high radon region for somebody who spends most of their time indoors in a poorly ventilated area, your exposure could be 10 times as high as the average radon exposure.

The estimated lifetime risk of a fatal lung cancer in the US, at the 4 pCi/L exposure level, is 1/625 for those who have never smoked, with radon the largest contributor to that risk. The risk is 1/33 for a typical smoker. That's an estimate for a single exposure level. Lower exposure should mean lower risk, and vice versus.

The average for homes across the US is 1.25 pCi/L, with 16% above 2 pCi/L and 6% above 4 pCi/L. About 1% of homes have very high radon exposure levels above 8 pCi/L. Getting your home from the action level down to the 2 pCi/L typically considered reasonably achievable could roughly halve your lifetime risk.

To explain this some of finer details about radon exposure related to grayfox's comments:

The air action limit is actually 4 pCi per liter, not per kg. That works out to 3265 pCi/kg. Due to the fact that alpha particle emissions from radon are much more easily absorbed by tissue than beta particle emissions from potassium-40 in food, it also has a biological effectiveness roughly 20 times as high as potassium 40.

Your body regulates its own potassium levels, so when you eat more potassium rich foods, your exposure does not change much since you quickly excrete the excess. If you spend time in more radon-rich areas, however, your exposure does change, because that level will be effectively continuously maintained in your lungs. The exposure is also almost entirely to the lungs, not diffused throughout the body like potassium.

All this taken together, the average background radiation dose in the US is estimated by the EPA at 2.28 mSv per year for radon, compared to 0.29mSv for other internal sources (food and water, including potassium-40).

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Re: radon mitigation exposure concern, are we at risk?

Post by RadAudit » Wed Aug 08, 2018 9:13 pm

mmmodem wrote:
Tue Aug 07, 2018 7:17 am
There is no safe level of radon.
+1

However, there is a level at which the risk from radon is well within the level of risks from the hazards of normal everyday activities.
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Re: radon mitigation exposure concern, are we at risk?

Post by tadamsmar » Thu Aug 09, 2018 7:15 am

grayfox wrote:
Wed Aug 08, 2018 1:23 pm
A basic look at what Radon is: Radon - Periodic Table of Videos: https://youtu.be/mTuC_LrEfbU

Radon (Rn 86) is given off as a gas from the radioactive decay of Radium (Ra 88).
Radium-226 -> Radon-222 + α α particle is Helium nucleus He.2+

Radon is also radioactive and decays. Half life is 3.8 days. Radon Decay Chain:

Radon-222 -> Polonium-218 + α 3.8 days.
Polonium-218 -> Lead-214 + α 3.1 minutes
Lead-214 -> Bismuth-214 + β- 26.8 minutes
Bismuth-214 -> Polonium-214 + β- 19.9 minutes
Polonium-214 -> Lead-210 + α 0.2 sec
Lead-210 -> Bismuth-210 + β- 22.3 years
Bismuth-210 -> Polonium-210 5 days
Polonium-210 -> Lead-206 + α 138.4 days
Lead-206 stable

So you start with Radium-226 and eventually end up with Lead-206, which is a stable nucleus.
The thing with Radon is that it is a vector for bioavailability.

Radon is an inert gas. It originates from the uranium and thorium in deposits below your home. The gas atom decays to a metal atom in the air. The metal atoms adhere to dust particles. Those can end up decaying in your lungs.

I can look over and see dust that settled out of the air on the table and computer beside me. If I had a Gieger counter I could easily detect a relatively higher level of radiation that dust. And that is in a home below the action level.
Last edited by tadamsmar on Thu Aug 09, 2018 9:49 am, edited 1 time in total.

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Re: radon mitigation exposure concern, are we at risk?

Post by Prudence » Thu Aug 09, 2018 7:24 am

mmmodem wrote:
Tue Aug 07, 2018 7:17 am
There is no safe level of radon. The EPA came up with a number for when remediation is necessary at 4.0 pCi/L but it doesn't mean 3.9 is safe. I'm not an expert, just a homeowner that did a lot circumspect internet research. Take what I say with a grain of salt and do your own research.

You already understand that radon is everywhere. You also have to understand that energy efficient homes especially ones with basements tend to have negative air pressure. That is, air is sucked into the home. Radon as a gas is sucked into the home and it concentrates in the home. At higher concentrations is where it radon becomes a big issue.

That means even if you stick your head and breathe in the exhaust, you're not necessarily getting more radon than if you were sitting on the front porch. You may if the system hasn't been running continuously so that radon built up in the home like after a black out. If it has been running continuously, it's just getting rid of ambient radon so that it doesn't collect in the home. Perhaps even the same ambient radon you would breathe in on your front porch.

Should you be concerned? Maybe. Two homes next each other may have drastically different radon levels if one of the homes just happens to sit on a high concentrations of radon.

I just bought a home that was tested at 3.6 pCi/L average. I was annoyed by this test as the chart clearly shows that radon peaks above 4 quite often on the chart. However, because the average is below 4, I had no grounds to ask the sellers for concessions on remediation. I've since purchased a battery operated home radon test device and have noticed how a basement window can increase or decrease radon levels drastically. I didn't bother with the one time only lab kits. I bought a $150 device that I can take with me to my next home.
I had our house tested for the first time two weeks ago and the radon level in the basement was 4.0 pCi/L. There has been little or no circulation in the basement which may be a factor (we don't spend any time down there). How frequently do you test the home you just bought? I am asking because I would like to buy a testing device so I can compute and track the average.

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Re: radon mitigation exposure concern, are we at risk?

Post by Call_Me_Op » Thu Aug 09, 2018 7:33 am

grayfox wrote:
Wed Aug 08, 2018 3:29 pm
Set of 4 videos from this guy who is an industrial hygienist and deals with human health hazards.

Radon 1 of 4: https://youtu.be/TYZglUjLE0Y

What is a Curie? 37x10^9 disintegrations per second. (initial decay rate of 1 gram of Radium)

What is a picoCurie (pCi)? pico is 10^-12, so 1 pC = 0.037 disintegrations per second. 4 pCi is 0.148 dis-integrations per second
A dis-integration is one decay event which emits one α particle, β- or γ radiation. Looking at the decay chain above, you can see that some dis-integrations are giving off α radiation and some β-

So the units pCi/L does not measure the concentration of Radon, but the amount of decay activity of all the elements (Ra, Po, Bi, Pb) in 1 liter of air.

A level 4 pCi/L of air means that there are 0.148 dis-integrations per second for each 1 liter of air. About one decay every 6.76 seconds.

EPA suggests a limit of 4 pCi/L (units are EPA pCi/L, which are a little different than regular pCi/L)
OSHA Permissible Exposure Limit = 100 pCi/L

Bananas 80,000 pCi/L
Milk 800-1200 pCi/L
Wine 400 to 800 pCi/L
Human Body: about 150 grams of K-40 (4,400 disintegrations per second)

The Wisdom of Paracelsus: The Dose makes the Poison

Hazard - the inherent ability to produce harm
Risk - the probability of that harm being realized

Radon 2 of 4: https://youtu.be/37pCurE0nxo

Safety - attaining an acceptable level of risk

27:52 Explanation of how EPA came up with Radon Dose-Risk Curve for Residential. (Linear No-Threshold Dose Response Curve)
You are confusing L with kg. The radioactivity of bananas, for example, is measured in Pci/kg - not pC/L. A kg is a lot of food.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

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Re: radon mitigation exposure concern, are we at risk?

Post by Call_Me_Op » Thu Aug 09, 2018 7:35 am

Prudence wrote:
Thu Aug 09, 2018 7:24 am
mmmodem wrote:
Tue Aug 07, 2018 7:17 am
There is no safe level of radon. The EPA came up with a number for when remediation is necessary at 4.0 pCi/L but it doesn't mean 3.9 is safe. I'm not an expert, just a homeowner that did a lot circumspect internet research. Take what I say with a grain of salt and do your own research.

You already understand that radon is everywhere. You also have to understand that energy efficient homes especially ones with basements tend to have negative air pressure. That is, air is sucked into the home. Radon as a gas is sucked into the home and it concentrates in the home. At higher concentrations is where it radon becomes a big issue.

That means even if you stick your head and breathe in the exhaust, you're not necessarily getting more radon than if you were sitting on the front porch. You may if the system hasn't been running continuously so that radon built up in the home like after a black out. If it has been running continuously, it's just getting rid of ambient radon so that it doesn't collect in the home. Perhaps even the same ambient radon you would breathe in on your front porch.

Should you be concerned? Maybe. Two homes next each other may have drastically different radon levels if one of the homes just happens to sit on a high concentrations of radon.

I just bought a home that was tested at 3.6 pCi/L average. I was annoyed by this test as the chart clearly shows that radon peaks above 4 quite often on the chart. However, because the average is below 4, I had no grounds to ask the sellers for concessions on remediation. I've since purchased a battery operated home radon test device and have noticed how a basement window can increase or decrease radon levels drastically. I didn't bother with the one time only lab kits. I bought a $150 device that I can take with me to my next home.
I had our house tested for the first time two weeks ago and the radon level in the basement was 4.0 pCi/L. There has been little or no circulation in the basement which may be a factor (we don't spend any time down there). How frequently do you test the home you just bought? I am asking because I would like to buy a testing device so I can compute and track the average.
When I had my house inspected, I asked for a radon test. It came in at 20 pCi/L in basmeent and 10 pci/L on first floor. The seller was pregnant, so was nervous when I told her about these results. In any case, I asked seller to mitigate, and they had sub-slab ventilation installed, which brought the level down to background.

As an aside, the installer told me that the depressurization motor would last for 5 years and then need to be replaced. It has been going strong for 15 years now. That's a Boglehead motor! :)
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Re: radon mitigation exposure concern, are we at risk?

Post by tadamsmar » Thu Aug 09, 2018 7:55 am

The laws do not protect you from buying a home with high levels of radon. The law provides little or no protection.

https://radonresources.com/blog/are-the ... itigation/

The link above provides a list of states that require warnings. I have bought homes in one of those states: NC. The warning is just a generic boilerplate revelation of a potential hazard that the buyer must sign at closing. It protects the seller from getting sued.

The standard pre-sale home inspection does not include a radon test.

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Re: radon mitigation exposure concern, are we at risk?

Post by Mako » Thu Aug 09, 2018 8:49 am

tadamsmar wrote:
Thu Aug 09, 2018 7:55 am
The laws do not protect you from buying a home with high levels of radon. The law provides little or no protection.
...
The standard pre-sale home inspection does not include a radon test.
True, but at least in my area a radon test is part of the standard contract as an inspection you can select and is typically requested by the buyer and made part of the inspection addendum. I am buying and selling right now and a radon inspection is part of both transactions, and it was the last few times I bought/sold. A previous home I bought it was over 20 when inspected so the seller got a mitigation system and got it down to 1-2. Definitely depends on local custom I imagine, as with most things real estate.

Of course also as with most things real estate both parties must agree...I tried to buy a different house a few weeks ago and the seller actually refused to allow radon to be part of the inspection contingency. I tested anyway and it was below 4 so I am not sure what their deal was. We ended up walking away due to other inspection issues, I think they thought they were selling the house as is, but I digress...

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Re: radon mitigation exposure concern, are we at risk?

Post by WhyNotUs » Thu Aug 09, 2018 9:05 am

No idea what Gray Fox's point is but if it is not to test and remediate for radon, then I believe they are off track regardless of what Youtube says. Radon is a proven threat, easy to test, and often easy to mitigate.

I would not be worried about my neighbors vent but it would make me ask my landlord for testing info and request that they pay for a test.
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Re: radon mitigation exposure concern, are we at risk?

Post by grayfox » Thu Aug 09, 2018 9:46 am

Sola dosis fact venenum. The Dose makes the Poison.

This basic principle of toxicology is credited to Paracelsus. "All things are poison and nothing is without poison; only the dose makes a thing not a poison." So what dose makes radon a poison and at what level is it safe?

Here's a table Table 8.4 Summary of national and international recommendations for indoor radon in dwellings. This is from https://www.ncbi.nlm.nih.gov/books/NBK230646/

Note: Most countries use Becquerel/meter^3. Becquerel (Bq) is the SI unit of radioactivity. One Bq is one nucleus decay per second, while a Curie is 37 billion nucleus decays per second. The conversion is 1 Bq/m^3 = 0.027 pCi/L

Here are recommendations for some other countries:
Australia 200 = 5.4 pCi/L
Austria 400 = 10.8 pCi/L
Belgium 400 = 10.8 pCi/L
Canada 800 = 21.6 pCi/L
Germany 250 = 6.75 pCi/L
US 150 = 4 pCi/L
Switzerland 1000 = 27 pCi/L

Most seem to be 200 or 400 Bq/m^3 = 5.4 or 10.8 pCi/L

It seems rather arbitrary. If you were Canadian and measure 8 pCi/L you would say No Problem, radon levels is way below the limit. But an American would freak out because he is twice the EPA recommended limit.

Now if you work down in a Uranium mine where the level is 2000 or 20,000 pCi/L, certainly it is not safe. Many miners got lung cancer. But what is a safe level? 2, 4, 5, 6, 10, 20? It depends on which country?

:arrow: It's all about setting the recommended limit. As far as I understand, at 4 pCi/L, about 6% of homes need mitigation. The lower the limit, the more homes will be swept up. WHO handbook on Indoor Radon recommends that countries set limit for indoor radon to 2.7 pCi/L. And Congress passed an act setting the target level of indoor radon at 0.4 pCi/L. This is 2/3's of all homes. (Average outdoors is 0.4 pCi/L.) See What is a safe and acceptable level of radon gas?
Last edited by grayfox on Thu Aug 09, 2018 11:06 am, edited 1 time in total.

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Re: radon mitigation exposure concern, are we at risk?

Post by tadamsmar » Thu Aug 09, 2018 10:25 am

grayfox wrote:
Thu Aug 09, 2018 9:46 am
Sola dosis fact venenum. The Dose makes the Poison.

This basic principle of toxicology is credited to Paracelsus. "All things are poison and nothing is without poison; only the dose makes a thing not a poison." So what dose makes radon a poison and at what level is it safe?

Here's a table Table 8.4 Summary of national and international recommendations for indoor radon in dwellings. This is from https://www.ncbi.nlm.nih.gov/books/NBK230646/

Note: Most countries use Becquerel/meter^3. Becquerel (Bq) is the SI unit of radioactivity. One Bq is one nucleus decay per second, while a Curie is 97 billion nucleus decays per second. The conversion is 1 Bq/m^3 = 0.027 pCi/L

Here are recommendations for some other countries:
Australia 200 = 5.4 pCi/L
Austria 400 = 10.8 pCi/L
Belgium 400 = 10.8 pCi/L
Canada 800 = 21.6 pCi/L
Germany 250 = 6.75 pCi/L
US 150 = 4 pCi/L
Switzerland 1000 = 27 pCi/L

Most seem to be 200 or 400 Bq/m^3 = 5.4 or 10.8 pCi/L

It seems rather arbitrary. If you were Canadian and measure 8 pCi/L you would say No Problem, radon levels is way below the limit. But an American would freak out because he is twice the EPA recommended limit.

Now if you work down in a Uranium mine where the level is 2000 or 20,000 pCi/L, certainly it is not safe. Many miners got lung cancer. But what is a safe level? 4, 5, 6, 10, 20? It depends on which country?

:arrow: It's all about setting the recommended limit. As far as I understand, at 4 pCi/L, about 6% of homes need mitigation. The lower the limit, the more homes will be swept up. I read that some want the target limit for indoor radon to be lowered to 2 or better 0.4 pCi/L, which is 2/3's of all homes. Average outdoors is 0.4 pCi/L.

See What is a safe and acceptable level of radon gas?
Canada has lowered its limit to 200. I did not check all those limits. Note that some countries have lower limits for new construction.

WHO recommends a limit of 100.

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Re: radon mitigation exposure concern, are we at risk?

Post by grayfox » Thu Aug 09, 2018 10:48 am

tadamsmar wrote:
Thu Aug 09, 2018 10:25 am

Canada has lowered its limit to 200. I did not check all those limits. Note that some countries have lower limits for new construction.

WHO recommends a limit of 100.
According to this, What is a safe and acceptable level of radon gas?, 200 and 100 are not safe. "A safe level of radon gas is no radon gas." The only safe level is 0.

Then they ask: "What is an acceptable level of radon gas?"
Radon Act 51 passed by Congress set the natural outdoor level of radon gas (0.4 pCi/L) as the target radon level for indoor radon levels.
I would not be surprised to see the recommended level lowered to 2.7 (100 Bq/m^3), 2, eventually 0.4. The lower the better, right?

I'm going to read that WHO HANDBOOK ON INDOOR RADON

Here's something just on 2nd page: "estimating the annual average concentration of radon in indoor air requires reliable measurements of mean radon concentrations for at least three months and preferably longer." So how good is a typical 48 hour radon test done by home inspectors? My guess is not very accurate.

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Re: radon mitigation exposure concern, are we at risk?

Post by ponyboy » Thu Aug 09, 2018 11:22 am

One of the biggest scams any homeowner can ever experience. Like others said...radon is everywhere. When you invite someone into your home to test for radon levels...how many times do you think they tell you its ok? Ive never heard of any. They will always tell you to install a vent system.

Its nothing more than fear mongering.

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Re: radon mitigation exposure concern, are we at risk?

Post by Call_Me_Op » Thu Aug 09, 2018 11:25 am

grayfox wrote:
Thu Aug 09, 2018 10:48 am
tadamsmar wrote:
Thu Aug 09, 2018 10:25 am

Canada has lowered its limit to 200. I did not check all those limits. Note that some countries have lower limits for new construction.

WHO recommends a limit of 100.
According to this, What is a safe and acceptable level of radon gas?, 200 and 100 are not safe. "A safe level of radon gas is no radon gas." The only safe level is 0.

Then they ask: "What is an acceptable level of radon gas?"
Radon Act 51 passed by Congress set the natural outdoor level of radon gas (0.4 pCi/L) as the target radon level for indoor radon levels.
I would not be surprised to see the recommended level lowered to 2.7 (100 Bq/m^3), 2, eventually 0.4. The lower the better, right?

I'm going to read that WHO HANDBOOK ON INDOOR RADON

Here's something just on 2nd page: "estimating the annual average concentration of radon in indoor air requires reliable measurements of mean radon concentrations for at least three months and preferably longer." So how good is a typical 48 hour radon test done by home inspectors? My guess is not very accurate.
The issue is not that's it's inaccurate, but that it is only accurate for the 48 hour period - not a long-term average. That said, if it's high during a random 48 hour period, I would want to mitigate it.
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Re: radon mitigation exposure concern, are we at risk?

Post by iamlucky13 » Thu Aug 09, 2018 11:40 am

Call_Me_Op wrote:
Thu Aug 09, 2018 11:25 am
grayfox wrote:
Thu Aug 09, 2018 10:48 am
I'm going to read that WHO HANDBOOK ON INDOOR RADON

Here's something just on 2nd page: "estimating the annual average concentration of radon in indoor air requires reliable measurements of mean radon concentrations for at least three months and preferably longer." So how good is a typical 48 hour radon test done by home inspectors? My guess is not very accurate.
The issue is not that's it's inaccurate, but that it is only accurate for the 48 hour period - not a long-term average. That said, if it's high during a random 48 hour period, I would want to mitigate it.
Right. Levels vary on a year round basis as well as with the weather, because both affect soil conditions that in turn affect how easily radon is released from the soil. It is also affected by activities like opening windows or running HVAC systems. And it varies by floor and even room.

I don't remember precisely offhand, but I think one recommendation is that if you have a measurement above 2 pCi/L, you should consider followup measurements at different times of year.

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Re: radon mitigation exposure concern, are we at risk?

Post by grayfox » Thu Aug 09, 2018 12:09 pm

One time, when I was buying a condo, I hired a home inspector for $300. The next day after the inspection, he called and said that he could do a radon test for an additional $90. He would place canisters in the home for 48 hours.

This was a 3rd floor condo and it was still occupied by the seller and his family. Somewhere it said that the doors and windows must be kept closed during the test. I'm thinking, it's the middle of summer, the occupants aren't going to keep the windows and doors sealed shut for two days. Maybe the seller will move the cans to the window sill and open the window. How is this test going to be valid?

I've read other stuff that says there are a million things that can change the results of the radon test:

A/C cycling on and off
furnace cycling on and off
doors open and closed
windows open and closed
season winter, summer
weather humidity, precipitation, wind, snow cover on roof, cloud cover
airborne particles, dust, burning candles
etc.

One guy says that a good way to improve radon test is to burn scented candles. Somehow the smoke particles reduce the measurement. I think that radon daughters attach to the smoke particles and fall out of the air. Surprisingly, I have heard that having an air filter running can make the test come out worse (higher).

:idea: I have to question how believable are the results from a typical radon test, especially if it is part of a buyer's home inspection.

Instead of hiring someone to test with charcoal canisters, I would rather spend money a Radon Detector. Then I have control over placement and test conditions. Here's one for $190.54 from Home Depot: Corentium Home Radon Detector.
Last edited by grayfox on Thu Aug 09, 2018 1:04 pm, edited 1 time in total.

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Re: radon mitigation exposure concern, are we at risk?

Post by queso » Thu Aug 09, 2018 12:15 pm

I'm no radon expert, but I've been running a ProSeries 3 in my basement for almost 5 years and I have seen my short term levels fluctuate from 1.x all the way to 4.4x. My long term average is in the mid to high 2's. I ran an Accustar kit about a year or so ago as a verification of my ProSeries 3 readings and it came back with a 104 day reading of 1.7 (June - October timeframe). DW freaked out a bit when the ProSeries 3 started beeping when we exceeded 4.x and now I am looking at DIY mitigation even though my short term levels have dropped back down into the 3's. I'm not too worried about it, but it is our exercise room, TV room, etc. so we spend quite a bit of time down there. The previous owner died of lung cancer at 39 and DW is a cancer survivor herself so her risk gauge is calibrated a bit differently than mine.

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Re: radon mitigation exposure concern, are we at risk?

Post by grayfox » Thu Aug 09, 2018 12:16 pm

ponyboy wrote:
Thu Aug 09, 2018 11:22 am
One of the biggest scams any homeowner can ever experience. Like others said...radon is everywhere. When you invite someone into your home to test for radon levels...how many times do you think they tell you its ok? Ive never heard of any. They will always tell you to install a vent system.

Its nothing more than fear mongering.
The national average for outdoor radon level is 0.4 pCi/L and some places higher. So you are right that radon is in the air everywhere on planet Earth. Whether or not it's a scam is another question.

Here's an article Simple Ways to Reduce Radon

The article talks about a ceiling fan coupled with a positive ion generator. The fan increases the plate out of radon decay daughters. "A Casablanca type ceiling fan can reduce radon by up to 95%"

He also writes about using a $12 4" computer fan in the ceiling vent for the furnace reducing the radon level. So there are inexpensive things you can try before spending $800 - $2500 for sub-slab depressurization (SSD). I bet if you hired a radon mitigation company, they would go straight for the SSD (expensive) solution. So, yeah, part of it is probably a racket.
queso wrote:
Thu Aug 09, 2018 12:15 pm
I'm no radon expert, but I've been running a ProSeries 3 in my basement for almost 5 years and I have seen my short term levels fluctuate from 1.x all the way to 4.4x. My long term average is in the mid to high 2's.
Is this the radon detector that you have?
Pro-Series 3 Electronic Radon Detector $149.99

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Re: radon mitigation exposure concern, are we at risk?

Post by queso » Thu Aug 09, 2018 1:27 pm

grayfox wrote:
Thu Aug 09, 2018 12:16 pm
queso wrote:
Thu Aug 09, 2018 12:15 pm
I'm no radon expert, but I've been running a ProSeries 3 in my basement for almost 5 years and I have seen my short term levels fluctuate from 1.x all the way to 4.4x. My long term average is in the mid to high 2's.
Is this the radon detector that you have?
Pro-Series 3 Electronic Radon Detector $149.99
Yep, that's the one.

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Re: radon mitigation exposure concern, are we at risk?

Post by iamlucky13 » Thu Aug 09, 2018 1:57 pm

ponyboy wrote:
Thu Aug 09, 2018 11:22 am
One of the biggest scams any homeowner can ever experience. Like others said...radon is everywhere. When you invite someone into your home to test for radon levels...how many times do you think they tell you its ok? Ive never heard of any. They will always tell you to install a vent system.

Its nothing more than fear mongering.
If you're saying the contractors are scammers who do not provide their customers accurate information about the guidelines established by the EPA and other competent authorities, I see that as credible in some situations. What levels have you heard of them recommending a vent system for, or have they been refusing to give homeowners test results to substantiate their recommendations in the cases you're referring to?

If you're purporting the research behind those guidelines is a scam, I have to insist you substantiate the argument. As roughly 30,000 non-smokers die from lung cancer every year in the US, if you believe one of the primary attributed causes for those deaths is mistaken, it is a serious enough discussion it should be backed up by data.

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Re: radon mitigation exposure concern, are we at risk?

Post by bhsince87 » Thu Aug 09, 2018 2:42 pm

Here are some data points for variability, using my Airthings Wave.

We live on a hill side, and the lower end of our basement is a 2 car garage. At the garage door side, readings have varied from about 1 to 3.

At the far end of the garage, readings have range from 1 to 4.5. It hit 4.5 twice.

Interestingly, both 4.5 readings came when my wife was out of town for a week, and the garage doors were not opened. It's typically open for onlly 2 cycles per day, so it apparently doesn't take much to vent the radon.

First and second floor readings have ranged from 1 to 3.7.

Out of curiosty, I have also measured areas outside, on the ground. I've measured as high as 2.5 in the open air.

We live in an area rated as high concern by teh EPA (can't remember if that is zone 1 or zone 3).

We are at the base of a mountain with a lot of natural springs, so I'm not suprised the open air levels are pretty high.

A home insector friend says he occasoinally finds homes with readings close to 100 in the living areas, and 1500-2000 in the basements.

I became concerned when a relative died of lung cancer that was possibly caused by radon. She was 75 years old, and had never smoked. Thier TV was in the basement, and she and her husband spent most of thier time down there. They had it tested and it came in at about 400. But her Dr said it is not possible to give a difinitive cause. Her husband never developed any problems.
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Re: radon mitigation exposure concern, are we at risk?

Post by megabad » Thu Aug 09, 2018 3:29 pm

Call_Me_Op wrote:
Tue Aug 07, 2018 7:25 am
Radon only reaches high levels when it accumulates in a home with poor ventilation. The outdoors is well ventilated.
This. If you are worried, open a window and stick a fan in it. This is a $20 solution to your fears.

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Re: radon mitigation exposure concern, are we at risk?

Post by iamlucky13 » Thu Aug 09, 2018 4:38 pm

BHsince87, it looks like your values are likely in pCi/L, while the inspectors values look like counts per second like a Geiger counter would report, or perhaps Becquerel per cubic meter. 100, 1500, and 2000 Bq/m^3 would correspond to 2.7, 41, and 54 pCi/L respectively. The latter are extremely high concentrations.

400 Bq/m^3 would be 10.8 pCi/L, which is fairly high, but not unusual in a high radon region.

Cancer tends to be very random. The National Research Council estimates that for every 250 non-smoking persons living in a home with that average concentration, almost all of them will be just fine, but one person will develop a fatal lung cancer from this. There's no known way to predict who it would be.
megabad wrote:
Thu Aug 09, 2018 3:29 pm
This. If you are worried, open a window and stick a fan in it. This is a $20 solution to your fears.
It is signficantly more than $20 if you factor in energy costs, especially in a place like Illinois, where heating bills already can be quite high. Long term, you'd want to specifically ventilate basements or crawlspaces or have sub-slab ventilation installed to intercept radon before it enters the home or at least ventilate unheated spaces.

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Re: radon mitigation exposure concern, are we at risk?

Post by megabad » Thu Aug 09, 2018 4:57 pm

iamlucky13 wrote:
Thu Aug 09, 2018 4:38 pm
It is signficantly more than $20 if you factor in energy costs, especially in a place like Illinois, where heating bills already can be quite high. Long term, you'd want to specifically ventilate basements or crawlspaces or have sub-slab ventilation installed to intercept radon before it enters the home or at least ventilate unheated spaces.
You are correct, a properly ventilated home can, at times, use more energy than a non-properly ventilated home. There are added benefits to increased ventilation though and I typically open windows at times (ie. crack them for short intervals) year round and it gets fairly cold here in winter. The choice to pay for a multi thousand dollar radon mitigation system or a $20 fan is a pretty easy decision for me. But radon is not high on my list of concerns in life.

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Re: radon mitigation exposure concern, are we at risk?

Post by tadamsmar » Thu Aug 09, 2018 6:08 pm

ponyboy wrote:
Thu Aug 09, 2018 11:22 am
One of the biggest scams any homeowner can ever experience. Like others said...radon is everywhere. When you invite someone into your home to test for radon levels...how many times do you think they tell you its ok?
Negative tests happen, as reported on this thread 3 hours before your post:

viewtopic.php?f=11&t=255872&p=4061322#p4060422

According to the EPA, 14 of every 15 homes test below the EPA action level.

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Re: radon mitigation exposure concern, are we at risk?

Post by afan » Thu Aug 09, 2018 6:21 pm

Radon levels vary, widely, through time, through the seasons and for reasons that remain unclear. Short term tests therefore don't tell you much. Some have recommended doing a long term test, for a year, to take into account the seasonal variation. If you are worried or think you know yourself to be in a high radon area, then you can do a short term test as well. If the short term values are too high, then you might want to do mitigation without knowing the long term levels.
The damage done by radon is due to long term exposure, so long term tests make more sense.
But if your next door neighbor had a high enough level to need mitigation then you should test your home.
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Re: radon mitigation exposure concern, are we at risk?

Post by tadamsmar » Thu Aug 09, 2018 8:18 pm

afan wrote:
Thu Aug 09, 2018 6:21 pm
But if your next door neighbor had a high enough level to need mitigation then you should test your home.
The EPA discourages that sort of conditional thinking, they just recommend testing. In the house that originally triggered the concern about radon: "state health officials found radon levels of 2,700 pCi/l, the highest found to date in a house. The house next door, however, had no radon gas."

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Re: radon mitigation exposure concern, are we at risk?

Post by grayfox » Thu Aug 09, 2018 8:47 pm

bhsince87 wrote:
Thu Aug 09, 2018 2:42 pm
Here are some data points for variability, using my Airthings Wave.

We live on a hill side, and the lower end of our basement is a 2 car garage. At the garage door side, readings have varied from about 1 to 3.

At the far end of the garage, readings have range from 1 to 4.5. It hit 4.5 twice.

Interestingly, both 4.5 readings came when my wife was out of town for a week, and the garage doors were not opened. It's typically open for onlly 2 cycles per day, so it apparently doesn't take much to vent the radon.

First and second floor readings have ranged from 1 to 3.7.

Out of curiosty, I have also measured areas outside, on the ground. I've measured as high as 2.5 in the open air.

We live in an area rated as high concern by teh EPA (can't remember if that is zone 1 or zone 3).

We are at the base of a mountain with a lot of natural springs, so I'm not suprised the open air levels are pretty high.

A home insector friend says he occasoinally finds homes with readings close to 100 in the living areas, and 1500-2000 in the basements.

I became concerned when a relative died of lung cancer that was possibly caused by radon. She was 75 years old, and had never smoked. Thier TV was in the basement, and she and her husband spent most of thier time down there. They had it tested and it came in at about 400. But her Dr said it is not possible to give a difinitive cause. Her husband never developed any problems.
This is very good information. I confirms what I thought about radon levels varying with many many factors--season, weather, windows or doors open/closed, doors, fans, A/C. I am concluding that having an home inspector place a couple of charcoal canisters for 48 hours is too blunt an instrument. Reporting one number, say 3.7, does not describe the situation. At a minimum they should show a range, 1 to 4.5 in the basement, etc. Or stats like average, min, max, percentiles.

I would compare it to measuring temperature. What's the temperature in my home? When and where? What were the conditions? I just got in and the temperature on thermostat showed 90 deg F. I guess that's what an inspector would report--90 deg F. If the limit was 72, it failed. Well, I was gone all day, and had the A/C off and all the windows closed, and it was a hot day. Of course it showed 90. If he did the same thing in January, it would show 58, and it would pass. One measurement doesn't tell the story.

I think that anyone that really cares would spend $150 and get a radon meter and make their own measurements under various known conditions. And I would do like you did, start with the outside. Find out what's the ambient radon level outside. Then take many different measurements over time and space inside, recording the conditions--window open/closed, fan on/off etc. Keep records. Science.

Mako
Posts: 109
Joined: Wed Feb 28, 2007 9:34 am
Location: Elkton, MD

Re: radon mitigation exposure concern, are we at risk?

Post by Mako » Thu Aug 09, 2018 9:16 pm

^in the past when I had inspections all I got was one value. I agree that could be of limited value. In the one I recently had they gave me 48 hourly values over two day. Ranged from 0.0 to 4.0 with an average under 2. Was interesting to see the range. Who knows how different it would be 3 or 6 months from now...

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