|1. The subject draft document was a clear, concise and thorough review of the current radon risk research.
2. Several commenters stated that the new lower reference level was not low enough. There was recognition that “optimization” should result in an appropriate adjustment for the US.
3. Line 965, Significant typo in stated value “4.40.10-3 WLM”
4. Paragraph B4, lines 1346-1357. The last three sentences discuss justification for the continued use of the previous value of 9 nSv per Bq h m-3 for dose per unit radon. These sentences should be revised for clarity.