EPA has maintained the position that radon measurement systems provide practical and affordable measurements that can give consumers the information they need about the radon level in their home in order to make a decision about whether to fix their home. Since EPA based this position on studies conducted earlier, we decided, in consultation with Office of Inspector General (OIG), to check the current state of device measurement accuracy.
This is a link to a contractor report that reviews current radon measurement proficiency data and compares it to earlier data -- http://www.epa.gov/radon/publications-about-radon. The report also provides a response to the OIG report regarding oversight of radon testing device accuracy and reliability (Rpt. No. 09-P-0151).
Results presented in this report support EPA’s position that radon testing devices provide accurate and reliable results and that EPA’s measurement recommendations raise the probability that high homes will be identified and fixed. While any measurement system has an associated variability in precision and accuracy, we expect that radon test devices that are used properly will provide accurate and reliable results.
The study presented here only represents a part of the picture of accuracy and reliability. Other efforts must be employed to contribute to this knowledge base; such as, blind studies carried out in the field, participation in the development of technical standards through private-sector, consensus-based processes, support of state program technical needs and assessments
of test chamber error.
View the report here -- http://www.epa.gov/radon/publications-about-radon.