There are many risks to manage with commercial properties, but one that is incredibly common and has the potential to also be incredibly dangerous is sometimes overlooked: radon.
While often associated with residential homes, radon is actually one of the most dangerous contaminants found in all types of commercial properties. So what is radon, how does it enter a property, and how can it be managed?
Radon: A National Health Risk
Radon is a naturally-occurring, colorless, odorless, radioactive gas that forms from the decay of elements found in rocks, soil, and well water. Inhalation of radon gas and its decay products can pose a significant health risk, and it has been identified as the second leading cause of lung cancer. Risk increases when exposed to higher concentrations over longer periods of time. The Environmental Protection Agency, American Medical Association, and the U.S. Surgeon General have named radon a national health risk, and there is no area of the country free of radon.
Anywhere on Earth
Wherever there is soil, there is radon, which makes it a concern for all property owners. Because it comes from specific elements in the soil—uranium and radium—geologic maps have historically been used to predict the likelihood of identifying elevated radon concentrations on a county basis. However, these maps have not proven to accurately predict the radon concentration in individual buildings or apartments.
The EPA makes clear it considers nowhere to be low risk or completely safe from radon, as high concentrations have been found in every map region of the U.S. Even adjacent buildings, homes or apartments may have drastically varying concentrations, which can be the result of a number of conditions. Therefore, property owners must understand the concentration level present inside a specific structure and residence.
Radon Vapor Intrusion
Outdoors, radon doesn’t generally pose a threat, since it quickly dilutes to very low concentrations. But indoors, it can become trapped and accumulate to dangerous levels. If the air pressure within a structure is less than the pressure of the surrounding soil (which is often the case), the structure can create a vacuum, drawing the gas inside through “cracks in concrete floors and walls, floor drains, sump pits, construction joints, around pipe penetrations, and through tiny cracks or pores in hollow-block walls.” Basements and ground floors generally have the highest concentration levels, but upper floors can also have dangerous levels.
For example, high-rise residential buildings are routinely found to have elevated levels of indoor radon transmitted to upper floors through stairwells, elevators, HVAC, plumbing and other utility riser enclosures and conduits.
Is Prevention Possible?
There are several factors that can influence radon concentration levels, which is why it’s possible to have adjacent structures with differing levels. For instance, the amount of uranium or radium in the soil directly under or surrounding a structure can result in higher radon gas emissions. Cutting, filling and imported fill material can all cause highly variable radon source material under an individual building. This, unfortunately, is not preventable and difficult to determine.
Groundwater and building materials can be other sources of radon intrusion. Properties relying on well water have an increased risk of the gas entering through plumbing. The amount of radiation in building materials such as concrete, natural stone or brick depends on the source of materials, type and amounts of materials used.
Ultimately, as not every factor is preventable or predictable, testing is key to ensuring indoor air quality is safe.
Radon Testing of Commercial Properties
Fortunately, radon testing is usually simple and affordable, though there are different protocols for testing commercial properties rather than residential homes. A certified radon specialist visits the site to conduct testing, which lasts about 48 hours. Over twenty states have training programs and/or licensure for radon testing and mitigation, so it’s best to work with professionals familiar with each state’s specific protocols. The general scope for a commercial property involves the following steps:
- Closing all windows and doors for a minimum of 12 hours prior to testing. (If occupied, use the main entry door only, and keep it closed as much as possible.)
- Radon test kits are placed in every room or unit of the building and must remain untouched for the 48 hours while data is collected. (Fans, fireplaces, and non-essential air purifiers or other sources of fresh air are not to be used, since they can alter the data.)
- After 48 hours, the specialist collects the test kits and sends them to a lab to be processed. The processing can be as quick as 24 hours, or may require several days.
- A specialist will analyze the results, create a report, and explain the test findings and recommendations.
Long-Term Testing and Mitigation Systems
The EPA unequivocally states that there is no safe level of radon exposure; exposure to even small concentrations over time could cause health issues. That said, the EPA considers concentrations above 4.0 pCi/L to be “action-level” and requiring reduction via a mitigation system. Federal entities such as HUD require mitigation for concentrations at these levels. The EPA also recommends owners of any properties with levels above 2.0 pCi/L consider installing a mitigation system. If initial test results return concentration levels of concern, ongoing testing is recommended to provide greater accuracy and determine the appropriate mitigation system, if necessary.
Installed for many types of toxic vapor intrusions, including TCE, the most common mitigation systems for commercial properties are sub-slab depressurization systems (SSDs). As previously mentioned, radon gases can enter structures because of pressure differences within the structure versus the surrounding soil. SSDs create a sealed pathway where the gases below the structure can escape through a venting pipe outside the property and disperse safely outdoors.
Simple Safety Solutions
The prevalence of radon makes it a risk that cannot be ignored, and testing procedures with minimal disruption (if any) and fast turn-around times make it all the more appealing for those who want to minimize risk. Working with EBI’s team of environmental professionals with their extensive industry experience is another simple choice for those who want quality, competency, and a truly consultative experience.
To learn more about EBI Consulting’s radon or other indoor air quality testing and mitigation services, contact us using the form below.
