MAH_2019

Protocol for Conducting Measurements of ANSI/AARST MAH 2019 Radon and Radon Decay Products in Homes 6 5.0 TESTING PROCEDURES AND OPTIONS 5.1 Detector Deployment Periods 5.1.1 Short-Term testing While deployment periods should optimally collect at least 48 hours of valid sampling time , deployment periods are required to be not less than 46 hours. For test durations of 2 to 90 days, testing is to be conducted under closed-building protocol conditions in accordance with Section 4 . Note—If a short-term test is longer than 2 days, it is best to terminate the test at a 24-hour increment from when the test was started to more evenly account for day-to-night fluctuations in radon entry. 5.1.2 Long-Term testing For test durations greater than 90 days, closed-building conditions are not required. However, if the goal of the long-term testing is to more closely evaluate annual exposures to radon in a home, the test period duration is to include heating season conditions that are not less than the percentage of the year when heating systems are active. Informative Advisories It is recommended when using long-term detectors for evaluating annual exposures that they be deployed for a minimum of 6 months over different seasons (one of which is a heating season) or as close to a year as possible to reflect seasonal changes in radon concentrations and building operation. Test durations that are longer than 2—7 days, such as 30-day or 60-day tests, serve to reduce the chance that short-lived temporary conditions in weather or building operations have adversely influenced test results. Note however that seasonal variations in weather and resulting building operation can be significant inmany climate regions. Tests conducted when a heating systemoperates both day and night aremore likely to provide a clear characterization of potential radon hazards. 5.2 The Time-Sensitive Testing Protocol Note—This protocol builds upon protocols developed by EPA relative to EPA’s “Home Buyer’s and Seller’s Guide to Radon”. Table 5.2 Time-Sensitive Testing Protocol (Required Procedure and Summary) Step 1 Options Simultaneous Testing Tests are to be conducted using two short-term test devices at the same time in the same location, 4 to 8 inches (10-20 cm) apart. Continuous Monitor Tests are to be conducted using a monitor that records retrievable hourly measurements. Step 2 Decisions to Fix the Building Mitigation decisions are to be based on the average result from a continuous monitor or the average of two test results conducted at the same time in the same location. 1 Fix the building if test results meet or exceed the action level , e.g., 4 pCi/L. Consider fixing the building if results are greater than half the action level , e.g., between 2 and 4 pCi/L. 1 Note—If two short-term test results disagree in terms of making a mitigation decision, see Section 7.2