Does anyone recall a large post mitigation radon survey (using yearlong follow-up ATDs) that was completed to assess the home radon concentration years after the mitigation was performed. The survey was at least 20 years ago and I thought it may have been coordinated by AARST?
Here are several papers that begin to address your question:
Findlay, Robertson and Scott 1990 Testing of Indoor Radon Reduction Techniques in Central Ohio Houses: Phase 2 (Winter 1988-1989), Research Triangle Park, NC: EPA AEERL
Findlay, Robertson and Scott 1991 Follow-up Durability Measurements and Mitigation Performance Improvement Tests in 38 Eastern Pennsylvania Houses having Indoor Radon Reduction Systems, Research Triangle Park, NC: EPA AEERL
Scott and Robertson, 1989 Follow-Up Alpha-Track Monitoring in 40 Eastern Pennsylvania Houses with Indoor Radon Reduction Systems (Winter 1987-88), Research Triangle Park, NC: EPA AEERL
There may be some more AARST Symposium papers that I could search if they do not pop-up from others.
Thank you for your work on the Science Advisory Committee considering the threshold question,
Thank you Bill. These are helpful, but the study I was thinking about was more of a national study. I know year long follow-up tests were performed in Iowa and other states.
Bill,
NJ did a Follow-up study on Mitigated homes. Then they looked at ones that failed and that was the basis of a training course and update for the manuals. I think Camroden and Bill Brodhead were involved. I may have a copy home that I could access during the week.
There were formal grant reports on this project. I scanned a bunch of these before I retired. I will see if I can find this them this week now that I have access to my old laptop and flash drives. I will also check with Anita Kopera at NJDEP.