MAKING MITIGATION DECISIONS BASED ON SHORT-TERM TESTS OF RN-222

One test option recommended by the EPA for deciding to mitigate involv es up to two short-term measurements. If the initial measurement is gr eater-than-or-equal-to 148 Bq m-3, the test is repeated and the house is mitigated only if the mean of the two measurements is greater-than- or-equal-to 148 Bq m-3. The frequency of errors under this test option was evaluated using 2-d and 1-y measurements from 1,449 houses. The c hances of making incorrect mitigation decisions vary from 1% to more t han 50%.