From my experience of over 15 years as a home inspector and PA DEP licensed radon testing professional, I know that radon is an often confused subject among most home buyers and sellers and even many real estate agents. I hear many agents tell their clients 'not to worry about radon' or that 'radon is not real'. Well, it is indeed a real thing; its number 86 on the periodic table of elements and is a known health risk.
What is radon?
Radon is a radioactive gas that comes from the normal breakdown of uranium and other elements in the ground. It has no smell, no taste, and you can’t tell its concentration in your home without performing a simple radon test. As a normal part of nature, some substances within the Earth rise to the surface and radon gas is one of them. Some amount of radon is present in almost all homes, and, according to the US EPA, the south central PA region has the highest average indoor concentration of radon in the USA. This conclusion is based upon many years of actual test data collected from professional tests performed across the USA.
According to the US Environmental Protection Agency (EPA), radon is the second leading cause of lung cancer, after smoking. Approximately 22,000 Americans die from radon-related lung cancer annually. That is more than 6 times the number of deaths attributed to house fires and carbon monoxide (CO) poisoning combined! The use of tobacco substantially multiplies the risk of radon-related lung cancer (by a factor of approximately 15 times).
How does radon get into my home?
The EPA recommends that every home be tested for radon. The vast majority of it emanates from the soil. It can enter the home in various ways; the most common is through cracks and voids in foundation walls and floors, and to a lesser degree via well water and building materials. We all know that warm air rises, so radon gas is also affected by indoor ventilation, such as the stack or 'chimney' effect. High radon levels have also been measured in schools and other buildings.
The stack effect relates to warm air rising within a structure and the need for replacement air to take its place from beneath. The stack effect can be driven by the method of heating that the home uses, direction and force of exterior winds, open vents and flues, and other combustion appliances. The space beneath a basement is most often the source of much of the replacement air. Since this space is in direct contact with the earth and radon most commonly emanates from the soil, this is the most common transport mechanism into a building.
Some real estate agents and home owners are erroneously under the belief that radon levels can’t be high in a city home or a new home or if the home is built on concrete slab (no basement) or over a crawl space. I have personally measured high (and low) levels in all types and locations of area homes with and without basements.
While a home's highest radon level is often found in a basement, this is not always the case. The same goes for the home's age; I have found high concentrations in 200 year old homes and brand new homes and everything inbetween. All homes should be tested.
What on earth is a “picoCurie”?
Radon concentrations are most commonly measured in picoCuries (pronounced "peek-o-ker-ees") per Liter of air and abbreviated as pCi/L. A ‘Curie’ is a unit of radiation measurement named for Pierre and Marie Curie. Radiation is all around us; much of it naturally occurs from sources such as space and inside our bodies, but also comes from many other places, such as radon and medical sources (such as X-rays). There is much more radiation exposure from radon and X-rays than from nuclear power plants, cosmic rays, etc. Since breathing is the easiest way for a gas to enter the body, lung cancer is the primary result of radiation exposure related to radon.
Any level of radon (and radiation) may present a health risk. The US EPA has compiled a considerable amount of data relating to radiation exposure and results on the human body. The EPA has chosen 4.0 pCi/L as the Recommended Action Level. If a radon test result is 4.0 pCi/L or higher, remediation is recommended. Levels under 4.0 pCi/L may also be unsafe, but reduction methods in some cases may be more difficult under this level in certain homes. Even if a test shows a concentration less than 4.0 pCI/L, simple things like remodeling a home, weather-stripping doors or windows, reglazing windows, replacing HVAC equipment, or nearby blasting can change or create new entry points of radon into the home or affect internal drafting. In cases where one of the above occurs, performing another test is recommended.
What is used to measure radon?
Radon can be tested using several different technologies, including continuous radon (CR) monitors, e-Perms (Electret), activated charcoal (AC). These are the 3 most popular testing devices. Each has its own advantages and disadvantages although the continuous monitor is the most common technology used for professional testing during a home transaction.
Continuous Radon Monitor (photo courtesy of Sun Nuclear Corp.)
ePerm (photo courtesy of Rad Elec, Inc.)
Activated Charcoal Test Kit
Closed House Conditions
Since radon concentrations can depend upon air movement, to properly and reliably test inside a structure, the EPA has set specific standards or protocols for testing called "Closed House Conditions" to help limit exterior effects and ensure reliable test results. The EPA defines “Closed House Conditions” as all exterior doors and all windows in the home (not just basement doors and windows) kept closed starting at least 12 hours prior to the start of the test. This does NOT mean to close the windows and doors once the inspector arrives to start the test. Exterior doors can be opened and closed momentarily for normal entering and exiting the home, but must otherwise remain closed during the test. Central heating or A/C systems must be run normally beginning 24 hours prior to the test's start and then throughout the test's duration. This helps ensure real life occupancy conditions in the home. Whole-house fans and window or wall mounted A/C units (unless running in circulating mode) must not be operated during the test since they exchange air with the exterior. Chimney flue dampers should also be closed and fireplaces should not used during the test unless they are the home's only heating source.
PA DEP has documented set standards and protocols; some of the PA protocols are more stringent than what the US EPA requires. PA DEP protocols supercede EPA rules for PA DEP professionally licensed testers and remediators. In some cases, PA DEP radon testing protocols are different and are more stringent than EPA standards. PA DEP requires that radon testing occur in the lowest possible living level. This normally is the basement unless there is a dirt floor or the ceiling height (between the basement floor and underside of the main level's floor joists) does not allow for normal living conditions.
When the inspector arrives to drop off and retrieve the test, he will do his best to verify that closed house conditions have been met. The inspector will communicate with the seller or home’s occupant a day or so prior the test's start to review PA DEP (Dept. of Environmental Protection) radon test protocols and answer any questions. This communication is made before the test starts because the test protocols begin well before the test starts and the home must be ready for the test to be performed.
Most, if not all, certified radon testers have the home's seller or occupant sign a test agreement which explains the test criteria and also is a form of quality control. This form helps ensure that the owner or occupant understands and will fully comply with the required test protocols and affirms that they won’t interfere with the test. Should any evidence of inference be noted based upon that the inspector finds or what the test results indicate, the test must be voided per PA DEP protocols since the results can not be relied upon for accuracy.
The EPA and PA DEP also have specific requirements regarding where in the home radon testing can occur. This is related to things such as proximity to windows, vents, and outer walls as well as near sources of moisture like kitchens, bathrooms, and laundry rooms.
Click here to learn more about PA DEP Radon Testing Protocols. These protocols ensure quality control and sets standards for PA DEP radon testing professionals.
What if a radon test indicates a high radon level?
If a radon test shows a high levels, remediation (also called mitigation) can be successful in lowering the home’s radon level in most circumstances. The most common method of remediation is a sub-slab depressurization system. To put it simple, one (or more) hole is drilled through the foundation slab (often the basement's concrete floor), a small amount of dirt is excavated under the slab, PVC pipe is installed with a special fan, and this system vents to the exterior away from doors and windows. Radon fans can only be placed in an attic or at the exterior of the home, but can not be installed in the home’s living space or in the garage.
Since inspecting homes since 2002, I've seen many improper radon system installations. The Commonwealth of PA has specific requirements (called the "PA Radon Mitigation Standards") about how and where remediation systems can be installed. Professional remediation systems in PA must be installed to these standards. The cost of a professionally installed remediation system in our area is generally in the $800~$1,200 range. Remediation system designs (and their pricing) can vary based upon the home’s layout, the initial test result, type of system installed, number of suction points needed, etc. PA DEP also requires that when a professional remediation system is installed and is started up, a retest must occur between 24 hours and 30 days.
The professional remediator who installed the system may not perform the retest; this is to prevent a possible conflict of interest. The remediator will either provide a test kit to the home owner (or new home buyer) to perform the test themselves (and then mail the test device to a certified lab for the results) or will pay a separate PA DEP certified tester to perform a professional retest.
It is very important that the retest be performed promptly after the remediation system is running so that lower radon levels inside the home with the system running can be confirmed. I have personally tested high levels in quite a few homes with running remediation systems; when a home owner or potential buyer sees the installed remediation system or the installed manometer, they most often assume that the system is working as intended and the radon levels inside the home are low. Again, the only way to know is to test.
Who performs a radon test and remediation?
The PA DEP requires that all individuals or firms performing professional radon testing or remediation be licensed by the Commonwealth of PA. A home owner or builder can perform radon testing and remediation in their own homes, however a PA DEP licensed testing professional should be used for a home transaction to ensure a non-compromised test performed to PA DEP protocols. Any changes to an installed remediation system should only be performed by a licensed remediator, as well. Contractors (plumbers, electricians, etc.) who are not PA DEP licensed for radon remediation should never modify remediation piping or their fans in any way; this is against the law in PA per the PA Radon Act. Even minor changes to remediation pipes and fans may cause the system to not work properly, may lead to condensate damage within the home, and/or may raise the radon concentration within the home.
The PA DEP updates its list of certified/licensed radon testers and radon remediators each month. This info can be obtained from the PA DEP website or by calling the PA DEP at: 1-800-23-RADON.
© 2014 Matthew Steger
Addition information can be found at these various web links:
- EPA Citizen's Guide To Radon
- Home Buyer's and Seller's Guide To Radon
- Consumer's Guide To Radon Reduction
- EPA Map of Radon Zones
- PA Radon Mitigation Standards
- Buying A New Home: How To Protect Your Family From Radon
- EPA's Risk Assessment of Risks From Radon In Homes
Matthew Steger, owner/inspector of WIN Home Inspection in Lancaster, PA, is PA DEP certified/licensed to perform radon testing in the Commonwealth of PA. He also teaches a "Radon 101" course for continuing education for Realtors® at the Lancaster County Association of Realtors (LCAR).
He is also an ASHI Certified Inspector (ACI) and a Certified Level 1 Infrared Thermographer. He can be reached at: 717-361-9467 or firstname.lastname@example.org.
WIN Home Inspection provides a wide array of home inspection services in Lancaster, PA and surrounding areas. This article was authored by Matthew Steger, ACI - owner of WIN Home Inspection in Lancaster, PA. No article, or portion thereof, may be reproduced or copied without prior written consent of Matthew Steger.