Radon – a naturally occurring radioactive, carcinogenic gas that can migrate into a property through water or air– poses a serious health threat, especially in certain areas of the country (see this EPA map for zones with high potential for elevated radon levels). Many states, including California and Illinois, require radon testing and disclosure during real estate transactions (for an article about the effects of radon on real estate deals see here). The EPA recommends that all homes be tested for elevated levels of radon regardless of geographic location or zone designation, and many lenders include radon testing in their due diligence requirements. While radon testing in and around real estate transactions can be done quickly and inexpensively, accuracy is critical to adequately assess health risks to occupants.
What The Experts Were Saying At The 2014 International Radon Symposium
Promoting high quality radon evaluations was exactly the mission of the 2014 International Radon Symposium that I attended in South Carolina last week. The convention highlighted (among many topics) protocols for conducting radon measurements in multifamily buildings, as described in a 2012 document published by the American Association of Radon Scientists and Technologists (AARST). Key themes and recommendations for radon testing procedures that came out of the panel discussions included:
- More accurate, short-term results would be obtained by conducting 4-day radon tests.
- Apartment occupants whose apartments are not being tested should be notified and required to follow the closed building conditions before and during the radon testing period to prevent “Stack effect” influence on the subject building(s). Stack effect usually creates a negative vacuum, drawing more soil gasses and radon into the building. When to notify occupants? At least 2 weeks before testing begins, with a reminder 48-hours prior to the commencement of radon testing.
- Radon assessors should consider following AARST’s Time-Sensitive Testing Protocols (which correspond to the EPA’s Home Buyer’s and Seller’s Guide to Radon). This means either:
- conducting 2 short term passive (i.e. charcoal) tests at the same time in the same location. Our HUD team utilizes this testing approach on all projects located in EPA Radon Zone 1; or
- testing the unit with a continuous monitor.
- The results of a single, short-term passive test should not be used as the basis for determining whether to mitigate an area. If recommending long-term passive testing, tests should be performed over a period of as close to a year as possible ensuring that the test period includes multiple seasons.
- Mitigation should take place when results of the radon test are twice the action level, which is 4.0 picoCuries (pCi/L) as established by the EPA. Specifically:
- Mitigation should be considered if the initial test results I <4.0 pCi/L but >2.0 pCi/L (EPA states that no level of radon is safe);
- Mitigation should be performed if long term test results are >4.0 pCi/L; and when averaged test results are >4.0 pCi/L
- To accurately determine whether the building versus the unit should be mitigated, consult with a mitigation professional.