Radon in Granite Countertops: Don't Worry.

Back in 2008 there was a media scare related to radon in granite countertops.  The scare went something like this: radon causes lung cancer.  Granite contains radon.  Therefore, granite causes lung cancer.  There was even an article published in the New York Times, where some guy was actually quoted as saying "It's not that all granite is dangerous, but I've seen a few that might heat up your Cheerios a little."



I figured this media scare would quickly be forgotten about, but it seems there is still some information floating around making people worried about granite, as I recently had a client ask me whether he should be worried about elevated radon levels in his new house because of the granite countertops.

I'm not worried granite countertops. Not the slightest bit.  As for that New York Times article and the idea that some granite might heat up your Cheerios... I'm sorry, but that's just absurd.  In the same article, another expert says you have a better chance of getting struck by lightning than being at risk for cancer because of radon in granite.  Granite countertops may contain trace amounts of radon, but not enough to be of any consequence.  Being worried about granite is a little bit like being afraid of dirt. From everything I've read about this scare, I think it's mostly a laughable smear compaign; the people saying granite countertops present a radon risk are largely the manufacturers of competing products.  Gee, imagine that.

If want to learn more about this topic, read what the unbiased parties have to say.  Check out the EPA info on radon in granite, or read this Position Statement on Granite Countertops and Radon Gas from the Technical and Science Committee of the American Association of Radon Scientists and Technologists (AARST).  The bottom line from both is that you should have the radon levels in your home tested, whether you have granite countertops or not.

Reuben Saltzman, Structure Tech Home Inspections - Email- Radon Testing in Minnesota
    

Could My Radon Monitor Be Broken?

One of the more awkward conversations that I had with a home seller this year dealt with a high radon test at his home in Minnesota.  We performed a radon test for the buyer, and the test came up high (over 4.0 pCi/L), so the buyer asked the seller to install a radon mitigation system.  The seller wasn’t happy about this, so he called us up to complain.

We had performed a radon test for the seller when he bought the home four years ago, and the test was below 4.0 pCi/L.

I could understand the seller’s frustration; I would have been frustrated too.  How could this be?  Was our electronic radon monitor broken?  No, it really just came down to timing.  Radon levels constantly fluctuate throughout the day, and even throughout the year.  There are many factors that affect radon test results - so many that you'll never get the exact same results twice.  A few of the larger factors include:

• Where the test was placed in the home.
• Barometric pressure.  Rainy weather = lower pressure = higher radon levels
• Ventilation systems.  An HRV running at full speed can cut radon levels in half.
• Windows open vs closed.  Houses always act like chimneys; warm air rises.  This creates negative pressure in the basement and positive pressure at the upper levels.  When windows are open at the upper levels, the house will act even more like a chimney, which increases radon levels.  That's right; opening windows on the upper levels can actually increase radon levels in the basement, which is where the test is placed.

With all of these factors, why even bother with a short term radon test? Because it helps to decide whether or not radon is a problem that needs to be dealt with.   The overall seasonal average typically won't be too far off from the short term test.

I performed a radon test at my own house for 96 hours, and as you can see from the graph below, the levels didn't vary all that much.  The overall average came out to 2.6 pCi/L.  If you were to only look at the highest levels in a 48 hour period for this test, the average would still only be 2.9 pCi/L.  I've performed many tests at my house throughout the year, and the average is consistently between 1 and 3.

For the record, we have every one of our electronic radon monitors calibrated annually.  While radon levels may be volatile, the accuracy of our tests isn't.

Reuben Saltzman, Structure Tech Home Inspections - Email - Minneapolis Home Inspections
    

Six Things To Consider Before Testing For Radon On The Home You're Buying

If you're buying a house in Minnesota and you want to have it tested for radon as part of your inspection contingency, here's a list of six items that the EPA says you should consider before you have the test conducted.

Where the radon test will be located

The radon test should be placed in the lowest level of the home that could be used regularly, whether it's finished or not.   I've said before that radon tests should never be placed in crawl spaces, but what if the basement ceiling height is 6' 11" ?  The Minnesota State Building Code defines a crawl space as "Areas or rooms with less than 7 feet ceiling height measured to the finished floor or grade below.” (MN Rules 1309.0202)    This is a grey area that should be discussed ahead of time.

Who should conduct the radon test

 Call Structure Tech, duh!  We've been testing radon in Minnesota for more than twenty years.

What type of radon test to do

A radon test performed with a continuous electronic monitor can be completed in as little as 48 hours.  The other type of test that is most commonly used for a real estate transaction is a charcoal canister test.  This type of test must remain in the home for minimum of 72 hours, and then the canisters must be sent to a lab for analysis.  Do you have time to get the testing completed?

When to do the radon test

The occupant of the home must maintain closed house conditions for 12 hours prior to, and throughout the duration of the radon test.  This means keeping windows and doors closed, except for normal traffic.  A few things that make this difficult would be if the seller is moving, if the home is under construction, if it's new construction, or it's a hot week in August and the home doesn't have air conditioning.  Stuff to think about...

How the seller and the buyer will share the radon test results and test costs

The issue over the test costs is a no-brainer; if the buyer wants a test, they should pay for it.  If the seller doesn't want to know about the test results, they should make that clear ahead of time.  Whywouldn't the seller want to know?  If the test is high, this must now be disclosed to any future buyers if the deal falls apart for any reason.

When radon mitigation measures will be taken, and who will pay for them.

This is the big one.  Ideally this would be decided ahead of time, but I've never heard of this actually happening.  If the radon test comes up high, most home buyers will ask the seller to install a mitigation system, but will the seller be willing to do this?

While I'm certainly an advocate of radon testing, one of the few times that I don't recommend testing for radon at the time of a home purchase is when the results aren't going to make any difference. In other words, if the buyer has decided to purchase a home regardless of the radon levels and the seller is unwilling to mitigate high levels of radon, there's no point in having a professional test performed ahead of time.  The buyers would be just as well off performing a long-term test on their own after they purchase the house.

Reuben Saltzman, Structure Tech Home Inspections - Email - Minneapolis Home Inspections