To provide background information for the Panelists on the issues in preparation for the advisory activity. The Panelists are to: (a) discuss the charge, review and background materials provided to the Panel; (b) to discuss specific charge assignments for the Panelists; and (c) advise the Office of Radiation and Indoor Air (ORIA) of any specific points that may need clarification for the December 19-20, 2005 meeting.