The Scourge of the Shenandoah: Understanding Radon Gas

Florida and the Gulf Coast have hurricanes. The Midwest has tornadoes. California has wildfires and earthquakes. The Shenandoah Valley has radon.

Unlike hurricanes, tornadoes, fires, and earthquakes, radon is never going to grab headlines. Though a dangerous natural phenomenon – it is the second leading cause of lung cancer behind only smoking – there’s nothing to see. We’ll never witness a wacky weather reporter wrapped in oilskins fighting back a furious front of radon for a national television audience. The major news outlets will never feature dizzying shots of military aircraft dropping gallons of water on a radon outbreak. No iconic images of stalwart service workers rescuing refugees from wreckage and rubble will ever be associated with radon.

No. Radon makes no sound. It doesn’t strikes in storms. It leaves no sights to be seen. And this makes it all the more dangerous.

Radon gas is produced by the breakdown of uranium, an unstable element. A person’s exposure to radon is very much dependent the on soil geology under their homes, offices, and other places they frequent. The more substantial the source under a building, the greater the risk of exposure.

Because of variances in soil geology, some places present a higher percent chance of exposure than others. Most coastal regions are EPA Zone 3 areas where the relative chance of exposure is fairly low. The Shenandoah Valley, on the other hand, is an EPA Zone 1. In relative terms, substantially more radon gas exposure takes place here than most places in the country.[1]

From the Virginia Department of Health

Due primarily to the fact it can’t be detected without specialized equipment, radon is a misunderstood phenomenon. The purpose of this post is to address some of the most frequent misunderstandings and myths that I encounter. This is not a comprehensive overview. The EPA has some well-honed, fairly short publications available for anyone who wants a full working knowledge. I want to provide a broad-understanding and spread awareness.

Myth 1: Radon gas is explosive

This is not true, but it comes up more often than you might think. As mentioned earlier, radon gas cannot be detected without specialized equipment. Moreover, the distribution of radon in the ground is not uniform. Many a homeowner has been harried by the fact that you can have high levels of radon gas at your house and your neighbor can have an almost immeasurable amount. The only way to know is through testing.

Myth 2: Radon isn’t really anything to be worried about.

I have run into a fair number folks who “don’t buy the hype” or don’t think radon is a real concern. The thinking usually goes like this: I wasn’t hearing about radon ______ years ago, so this must be something that’s being propped up so I have to pay someone to “fix it”.

Radon is a real thing and poses a measurable threat. Research for it hasn’t always been well-funded, but has continued to increase since the 60s. As with most building technology our understanding of safety improves constantly. Let’s not forget that if your house was built in, say, the 1960s, the folks who built it probably smoked unfiltered cigarettes and drove home in cars without seatbelts.

Numerous university and government studies have confirmed that radon gas poses a health hazard.

Myth 3: Radon can be eliminated.

Radon gas can no more be eliminated from a house or area than oxygen. The average outdoor level is .4 pCi/L. Don’t worry about the unit of measurement; the point is that radon gas is, to some degree, always in the air we breathe. The only way to create a radon free environment is in a lab. The whole idea when it comes to remediation is get radon levels to a point so low it is almost negligible – much the same as avoiding exposure to tobacco smoke.

I have run into situations where homebuyers have become furiously frustrated in their failure to find a house that “doesn’t have radon”. This is a flawed way to approach the buying process. A buyer could potentially bounce from house to house for months or years before finding one that meets all of his or her needs AND has an acceptably low radon reading. The better approach is to be proactive and remediate the radon gas if it is above 4 pCi/L. This is the threshold for acceptable exposure as established by the EPA. Remediating also adds value to the house.

Myth 4: Radon testing is subjective / definitive.

A number of different methods can be used to perform legitimate radon tests, but variables do exist. Some radon tests, most notably those for school and municipal buildings, can run for months. The standard forty-eight hour real estate test is the shortest recognized test. It gives buyers a snapshot of the radon levels in a house, not the full picture.[1] Because radon is a gas that rises through the soil, levels vary: hour by hour, day by day, month by month. Weather, such as high winds, affects readings as the does the season in which the test is performed. Readings are typically higher in the winter because houses create a vacuum on the ground beneath them when heated.

What does this mean for homebuyers? If a reading is right around the threshold of 4 pCi/L, it might be wise to consider remediating or having a long term test performed. It likely that the real-time level dips and rises above the reading given throughout the year.

Myth 5: All remediation systems are the same.

Radon remediation systems come in two basic types: passive and active. The underlying idea behind radon remediation is to install a plumbing system that will give the gas a way to bypass the house. The foundation of the house gets sealed save for the pipe or pipes that penetrate below grade. Having no other way to rise, the radon gas proceeds through these pipes to the exterior and never enters the living space. A passive system is just the plumbing. An active system has a fan that continuously draws the air from beneath the house.

In my experience the active system is the more effective of the two. I have tested houses with passive systems that still had radon levels above the threshold of 4 pCi/L. Of all the houses with active systems I’ve tested, only one needed work – and it was due to some broken fan blades.

Active systems have a gauge to monitor performance.

Yes. Passive systems can be converted to active systems. The key thing to remember though is that it is wise to test even those houses that have remediation systems. You might put brakes on a car and never think about them again, but your car gets inspected every year to ensure their proper function. The EPA recommends testing radon levels every two years and after major alterations to the structure, such as moving / removing walls and adding additions.

Myth 6: The foundation of the house matters.

To some degree it does. Houses on slabs and crawlspaces are less prone to high levels of radon, but the ultimate determiner of whether or not a house has high levels of radon gas is the source beneath the house. I have tested houses on slabs and crawlspaces that needed to be remediated.

It is easy forget about radon, the Scourge of the Shenandoah. You can’t see it. You can’t smell it. You can’t taste it. Nobody has ever written a remorseful song about radon. No dramatic blockbusters memorializing defiance against radon will ever be shot. But it would be a mistake to understand its subtleness as benign. Our beloved Valley has high levels in part because our bedrock is shale and limestone, two very porous types of rock. These materials provide ready-made paths for radon dissemination and will be underneath us as long as we’re here. Instead of driving the thought of radon from your mind, have your home tested, and, if necessary, drive it from your home.

[1] Tests lasting less than 90 days are short term tests. Those lasting longer than 90 days are long term tests.

[1] Iowa has the worst of it. The entire state is an EPA zone 1.