I would like to add a few observations from the viewpoint of a state regulator. In VA, our trained professional radon testers outnumber our resident mitigators by roughly 5:1 and the disparity has grown worse over the last few years. Most of our mitigators are located around the major metro areas which has caused several mitigator "deserts" in many high risk areas of the state that have smaller populations. The recent hyper-competitive real estate market has also proved devastating for the businesses of many radon professionals. It seems to me that if our main goal is to protect the public from radon exposure, then we should be striving to make things easier on the mitigators, rather than more difficult. We should also do what we can to make the idea of installing a radon mitigation system more attractive to the typical home owner. To these ends, I think we already have enough scientifically valid information for the US to strongly consider adopting the Canadian model for both ground level discharge and internal fan installations. Of course we should also consider adopting additional and reasonable protective standards/guidance for both practices that would be more appropriate for the US market.
If it is AARST's view that we have not yet achieved scientific consensus on these issues, then they should commission their own scientific studies as soon as possible to settle these matters once and for all. In my opinion, the present regulatory disparity between the US and CAN has persisted for far too long and no longer adequately reflects accumulated knowledge and conditions in the industry.

Mr. Stein:
Here in VA we have prepared PPT presentations for on-site classes that we conduct free of charge for realty associations throughout the Commonwealth. We have three format lengths: 45 minutes (introduction suitable for webinar), 1 hr and 2 hr. The 1 and 2 hr versions have been approved by the VA Assn. of Realtors for CE credit. Of course some of the slides are applicable only to VA, but you could easily adapt these slides or remove them for your purposes. Please contact me separately and I would be happy to email you a copy of whatever you would like.

Ryan Paris
VDH-ORH Radon Coordinator
ryandotparisatvdhdotvirginiadotgov
W 804-864-8161