January 13, 2000


Ms. Carol Browner
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460

              Subject:       Commentary on the Agency's Proposed Drinking
                            Water Standard for Radon

Dear Ms. Browner:

       As you know, under the provisions of the Safe Drinking Water Act (SDWA), the Agency is
charged with consulting with the Science Advisory Board (SAB) prior to proposal of a drinking water
standard, and the SAB is charged with responding as it deems appropriate. This Commentary
constitutes the SAB's response to the Agency's recent issuing of a proposed drinking water standard
for radon.

       We have determined that a formal review of the proposed standard by the Board is not
necessary at this point. Over the past decade, Committees of the SAB have sent to you more than two
dozen reports on radon, its risks, and its mitigation, including a review prompted by Senators Chafee
and Lautenberg.  In the process, the science surrounding the risk assessment and risk management of
this issue has be subjected to numerous reviews  by the Board.  After hearing an Agency briefing to the
Radiation Advisory Committee earlier this month, two of us (Dr. Bull, Drinking Water Committee
Chair, and Dr. Johnson, Radiation Advisory Committee Chair) are satisfied that the science underlying
the proposed rule has been adequately reviewed through these numerous earlier SAB reports.

       While we are comfortable in not conducting a formal review of the proposed radon rule 
because of the extent of the Board's earlier involvement--, we are concerned that, in this case, the
Board had been inadequately alerted to the scheduling of events surrounding the rule.  Jf we had
determined, in fact, that an SAB review would have been necessary, the Board would have been hard-
pressed to conduct a rigorous review in the time remaining before promulgation.

       Therefore, we encourage the Agency to  be more forthcoming in sharing plans, schedules, and
expectations relative to issuance of drinking water standards in the future. For example, it is our
understanding that the Agency is planning to propose standards for arsenic and copper during the

current fiscal year.  We look forward to working with the Agency in conducting rigorous reviews of the
science underlying and incorporated into those proposals, should the SAB judge that such a review is
necessary.  In contrast to its 26 reports on radon over the past decade, the SAB has sent you six
reports on arsenic and only one on copper during the same time period. Therefore, it is more likely that
the SAB will have a substantive contribution to make in these cases than it has in the case of radon.

       We look forward to the response of the Assistant Administrator for Water to this  Commentary
and to working with the Agency in carefully planning value-added reviews of future proposed

                                    Dr. Joan M. Daisey, Chair
                                    Science Advisory Board
              /signed/                                    /signed/
       Dr. Richard Bull, Chair               Dr. Janet Johnson, Chair
       Drinking Water Committee                   Radiation Advisory Committee
       Science Advisory Board                     Science Advisory Board

       This report has been written as part of the activities of the Science Advisory Board, a public
advisory group providing extramural scientific information and advice to the Administrator and other
officials of the Environmental Protection Agency.  The Board is structured to provide balanced, expert
assessment of scientific matters related to problems facing the Agency.  This report has not been
reviewed for approval by the Agency and, hence, the contents of this report do not necessarily
represent the views and policies of the Environmental Protection Agency, nor of other agencies in the
Executive Branch of the Federal government, nor does mention of trade names or commercial products
constitute a recommendation for use.
Distribution and Availability: This Science Advisory Board report is provided to the EPA
Administrator, senior Agency management, appropriate program staff, interested members of the

public, and is posted on the SAB website (www.epa.gov/sab). Information on its availability is also
provided in the SAB's monthly newsletter (Happenings at the Science Advisory Board).  Additional
copies and further information are available from the SAB Staff.

                             SCIENCE ADVISORY BOARD
                              EXECUTIVE COMMITTEE

Dr. Joan M. Daisey, Senior Scientist, Department Head, Indoor Environment Department, Lawrence
       Berkeley National Laboratory, Berkeley, CA

Dr. Henry A. Anderson, Chief Medical Officer, Wisconsin Division of Public Health, Madison, WI

Dr. Richard J. Bull,  Senior Staff Scientist, Battelle Pacific Northwest National Laboratory,
       Molecular Biosciences, Richland, WA

Dr. Maureen L. Cropper, Principal Economist, DECRG, The World Bank, Washington, DC

Dr. Kenneth W. Cummins, Distinguished Scientist, South Florida Water Management District,
       Tarpon Bay Environmental Laboratory, Sanibel, FL

Dr. Linda Greer, Senior Scientist, Natural Resources Defense Council, Washington, DC

Dr. Hilary I. Inyang, University Professor and Director, Center for Environmental Engineering,
       Science and Technology (CEEST), University of Massachusetts Lowell, Lowell, MA

Dr. Janet A. Johnson, Senior Radiation Scientist, Shepherd Miller, Inc., Fort Collins, CO

Dr. Roger E. Kasperson, University Professor, Clark University, Worcester, MA

Dr. Morton Lippmann, Professor, Nelson Institute of Environmental Medicine, New York University
       School of Medicine, Tuxedo, NY

Dr. Joe L. Mauderly, Director & Senior Scientist, Lovelace Respiratory Research Institute,
       Albuquerque, NM

Dr. M. Granger Morgan, Head, Department of Engineering & Public Policy, Carnegie Mellon
       University, Pittsburgh, PA

Dr. William Randall Seeker,  Senior Vice President, Energy and Environmental Research Corp.,
       Irvine, CA

Dr. William H. Smith, Professor of Forest Biology, Yale University, New Haven, CT


Dr. Robert N. Stavins, Professor, John F. Kennedy School of Government, Harvard University,
       Cambridge, MA

Dr. Mark J. Utell, Professor of Medicine and Environmental Medicine, University of Rochester
       Medical Center, Pulmonary Unit, Rochester, NY

Dr. Terry F. Young, Senior Consulting Scientist, Environmental Defense Fund, Oakland, CA

Mr. J. Thomas Carrato, Assistant General Counsel, Regulatory Affairs, Monsanto Company,  St.
       Louis, MO

Dr. Ronald Kendall, Director and Professor, The Institute of Environmental & Human Health, Texas
       Tech University, Texas Tech University Health Sciences Center, Reese Center, Reese Center,
       Lubbock, TX

Dr. Costel D. Denson, Vice Provost for Research, University of Delaware, Newark, DE

Dr. Donald G. Barnes, Staff Director/Designated Federal Officer, Environmental Protection Agency,
       Science Advisory Board (1400A), 1200 Pennsylvania Avenue, NW, Washington, DC

Ms. Priscilla Y. Tillery-Gadson, Program Specialist, Environmental Protection Agency, Science
       Advisory Board (1400A), 1200 Pennsylvania Avenue, NW, Washington, DC