Evaluation of percentage-based radon testing requirements for federally funded multi-family housing projects

Abstract

Radon is a leading cause of lung cancer. Recommendations for radon testing in multi-family housing focus on testing a percentage of all units. There is considerable variability among recommendations as well as their implementation. I used the hypergeometric distribution to determine the probability of identifying one or more units with radon at or above 4.0 pCi/L for two prevalences (1:15, the U.S. average) and 1:3 (for states with many homes with radon ≥4.0 pCi/L) using two approaches. First, the distribution was used to evaluate the probability of finding one or more units with radon at or above 4.0 pCi/L when: (1) testing 10% or 25% of a range of ground-floor units; or (2) testing a varying percentage of units in 10-, 20-, or 30- ground-floor unit buildings. Second, the method was used to determine the number of units to be tested to identify one or more units with radon at or above 4.0 pCi/L with 95% probability, given a range of total ground-floor units. Analyses identified that testing 10% or 25% of ground-floor units had low probability of identifying at least one unit with radon at or above 4.0 pCi/L, especially at low prevalence. At low prevalence (1:15), at least 10 units need to be tested in structures with 20 or fewer total units; at high prevalence (1:3), at least 5 units need to be tested in units with structures having 10 or fewer units to achieve 95% probability of identifying at least one unit with radon at or above 4.0 pCi/L. These findings indicate that recommendations for radon testing in multi-family housing may be improved by applying a well-established and more rigorous statistical approach than percentage-based testing to more accurately characterize exposure to radon in multi-family housing units, which could improve lung cancer prevention efforts.

Keywords:

• Construction
• financing
• households
• poverty
• public policy

Conflicts of Interest

This research was an effort to address questions about radon testing posed by public, private, and academic partners working to identify and control radon exposure. The author has interacted with members of the American Association of Radon Scientists and Technologists (AARST), a professional membership organization, as a part of his work in this field on this and other research. AARST sponsored a portion of Dr. Neri's travel to attend the Annual International Radon Symposium and Trade Show to present his research in 2015. He has not received any funding from AARST directly for any of his radon-related research.

Acknowledgments

The authors wish to thank Dr. Harlan Austin, Bill Long, Susie Shimek, Dave Rowson, Phillip Jalbert, David Pawel, and Hilary Atkin for their support in this project.

Disclaimer

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention (CDC).