Evaluating and Assessing Radon Testing in Housing (EARTH)

Project Funder: New York State Department of Health (NYSDOH)/Health Research, Inc (subgrant from the U.S. Department of Housing and Urban Development)

Project Partners: New York State Department of Health (NYSDOH), consultants with the American Association of Radon Scientists and Technologists (AARST)

Project Contact: Jonathan Wilson, jwilson@nchh.org, 443.539.4162

What we’re studying: The optimal number of dwelling units to be tested in multifamily housing to identify buildings where radon mitigation should be conducted.

Why it matters: There are currently at least three different protocols in the U.S. on the number of dwellings to sample in multifamily housing for radon. There is no published evidence supporting the efficacy of these current policies in identifying resident radon exposure. This study will help identify an evidence-based policy. 

What we found: The study began in 2018. Data collection efforts are underway. Results are anticipated in late 2020.

Project Description

The goal of the Evaluating and Assessing Radon Testing in Housing (EARTH) study is to determine the minimum number of measurements needed to adequately assess the radon risk in U.S. multifamily housing. Radon is the second leading cause of lung cancer. Approximately 36% of the U.S. population live in multifamily housing. Currently, the recommended number of multifamily dwelling units that should be tested to assess radon risk varies from 10% (Fannie Mae) to 25% (HUD) and 100% (ANSI-AARST). There is no published evidence supporting the efficacy of the current policies in identifying radon exposure. The EARTH study will obtain radon measurements from radon professionals located in several states. The study anticipates collecting more than 7,000 results from 500 multifamily buildings. Each set of building measurements must have 100% of ground floor dwellings tested. Using standard statistical methods (hypergeometric probability, Monte Carlo simulation, power functions), random subsets of the measurements will be analyzed to determine the probability distribution and confidence level for the subset relative to that determined for the entire building database. This methodology will be used to assess the likelihood of different sampling protocols correctly identifying the risk of radon exposure.


Kitto, M. E., Murphy, C., Dixon, S. L., Jacobs, D. E., Wilson, J., & Malone, J. (2021, June 1). Evaluating and assessing radon testing in multifamily housing. Journal of Public Health Management and Practice. Online. DOI: 10.1097/PHH.0000000000001392 [Full text; automatic download]


Latest page update: January 12, 2022.