Evaluating and Assessing Radon Testing in Housing: The EARTH Study
Analysis of nearly 8000 radon measurements in multifamily buildings quantified the probability of missing a ground-contact unit containing radon using partial-testing protocols of 10-25% in multifamily housing. Based on measurement data for buildings with 5-26round-contact units, the confidence that there are no units with radon ≥4 pCi/L, based on various sampling percentages, was determined. For buildings of 5-26 ground-contact units, sampling 10% and 25% of ground-contact units failed to identify an average of 47-69% and 34-46% of ground-contact units with radon >4 pCi/L, respectively. To achieve 95% confidence that no units in the building have radon ≥4 pCi/L in buildings up to 20 units, 100% testing is required. For most multifamily building sizes, all ground-contact units in the buildings should be tested for radon.
Average Probability (%) of Partial Sampling Missing a Unit with
Radon Level >4 pCi/L at Various Sampling Percentages
| Number of Ground Contact Units | Number of Buildings | 10% Sampled | 25% Sampled | 50% Sampled | 75% Sampled |
| 05-06 | 45 | 58% | 34% | 19% | 5% |
| 07-08 | 71 | 55% | 36% | 15% | 5% |
| 09-10 | 40 | 65% | 39% | 24% | 9% |
| 11-12 | 37 | 52% | 41% | 21% | 8% |
| 13-14 | 14 | 51% | 35% | 20% | 7% |
| 15-16 | 20 | 47% | 32% | 15% | 5% |
| 17-18 | 15 | 59% | 39% | 21% | 8% |
| 19-20 | 12 | 69% | 46% | 23% | 9% |
| All | 276 | 58% | 38% | 19% | 6.5% |
Read the abstract or purchase the journal article
Evaluating and Assessing Radon Testing in Multifamily Housing, Journal of Public Health Management and Practice, June 1, 2021
Kitto, Michael E. PhD; Murphy, Calvin BSBA; Dixon, Sherry L. PhD; Jacobs, David E. PhD; Wilson, Jonathan MS; Malone, Jane