AARST_Radon_Reporter_Q32025_Single

14 | SEPTEMBER 2025 Radon-induced lung cancer is relevant to the financial services sector since radon levels in every building ever occupied by an individual affect their lifetime risk. • The occasion of a loan (upon rehab, re nancing, sale) facilitates removing the property from the risk pool through investment in radon testing (and mitigation if needed). While mobility makes individual risk imprecise in the sense that some occupants move each year (though not all occupants move every year) and not all buildings have the same radon level, resident mobility between properties does not diminish the serial risk presented to the multiple occupants of each unit over the life of a building. In reality, a higher number of residents in a unit with high radon levels increases the number of individuals for whom the property owner may be held liable. • Although lung cancer’s minimum ve-year latency period has been used as an argument against property owner liability for radon-induced lung cancer, 40% of tenants in multifamily buildings with ve or more units have occupied the same unit for ve or more (which includes one in six who have not moved for ten or more years). xvi Full compliance with 100% ground contact testing per the industry consensus standard does not add signifcant time or complexity as long as testing is properly specifed and executed. • A radon measurement professional can complete placement of test devices in 100-200 units in one day and retrieve them in a single day at the end of the testing period. • One common cause for delay is when the due diligence rm or other party has not provided the radon measurement professional the required property information in advance. • Invalid results, delays and extra costs (for retesting) arise when an untrained person conducting testing deviates from the standard’s device placement, closed building, or quality control requirements, or otherwise improperly handles test devices. • HUD reported in 2021 during a listening session on radon policy that the agency “has seen no discernable patterns of impact on application numbers or processing timelines at any of these points.” xvii Radon in HUD, Fannie Mae, and Freddie Mac Multifamily Lending Lending policies to test multifamily properties for radon have evolved over time. In January 2013, HUD’s O ce of Multifamily Development directed multifamily mortgagees to include radon testing in environmental reviews, and ensure needed radon mitigation, requiring the use of certi ed radon professionals but limiting testing to only 25% of ground contact (GC) units. xviii If elevated radon was determined present, additional testing was required to include the remainder of GC apartments to meet compliance with 100% of GC apartments tested. In December 2020, based on HUD-funded research indicating that testing only 25% of GC units had a 38% chance of missing a unit with high radon levels, HUD amended its radon policy to require 100% GC testing consistent with the EPA-recommended industry consensus standard. xix Fannie Mae and Freddie Mac multifamily policy mistakenly and prematurely eliminated in 2025. • Historically, Fannie Mae and Freddie Mac (GSEs) required testing one in ten ground contact (GC) units for radon for multifamily loans but did not require the use of certi ed radon professionals or adherence to industry consensus standards. For radon, all projects that are subject to NEPA’s related environmental laws must test for radon and install radon mitigation systems for any spaces that test above 4.0 picocuries per liter for radon. In addition, new construction projectsmust use radon-resistant construction techniques as described in the ANSI/AARST CC-1000 standard. Because installation of mitigation systems cannot occur before the environmental review is completed, this must be entered into the environmental review record as a mitigation measure. For new construction and substantial rehabilitation properties, all mitigation, including follow-up testing, must be completed and all reports submitted to HUD staff prior to final endorsement. Radon mitigation included as part of a Section 223(f) project’s repairs must be completed as quickly as possible and no later than 12 months after closing. The scope of work and related costs identified in the firm application must include all repairs related to radon. An operation and maintenance plan, called an operation, maintenance, and monitoring (OM+M) plan under the ANSI/AARST standards, must be administered per the applicable mitigation standard for any mitigation project. HUD attaches a condition to the firm commitment requiring that the borrower operate and maintain the property consistent with the referenced OM+M plan for the duration of the insured mortgage. The project must submit the final OM+M plan to HUD after the radon mitigation system is installed. • February 12, 2021: The Federal Housing Finance Agency (FHFA) directed the GSEs to revise their radon testing and mitigation policies. • November 3, 2022: FHFA directed the GSEs to adopt additional changes to their radon testing and mitigation policies, including testing 25% GC units, and testing additional units where elevated concentrations were determined present.