3
i UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D c 20460
July 19, IS88
TWE ADMJ MfSTW A 7QR
SAB-EKC-88-038
Honorable Lee M. Thomas
Administrator
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Subject: Science Advisory Board's review of BARIUM health
criteria document
Dear Mr, Thomas:
The Metals Subcommittee of the Science Advisory Board's
Environmental Health Committee has completed its review of the
Drinking Water Health Criteria Document for Barium dated December
1987, The review was conducted January 14-15, 1988 at the St.
James Hotel in Washington, D.C.
EPA's Office of Drinking Water (ODW) concluded in the
document that the 4.7 mg/L value recommended as a drinking water
standard by the National Academy of Sciences (NAS) in 1982 is an
appropriate value upon which to base both a Drinking Water
Equivalent Level (DWEL) and Reference Dose (RfD) for barium. ODW
asked the subcommittee if they thought that the choice of this
value was supported by the weight of scientific evidence.
The Subcommittee concluded that any value for the drinking
water standard in the range of 1 to 5 mg/L was consistent with
the scientific evidence. Since it is unclear in the text of the '
criteria document how the NAS derived its value (although it
appears to come from a 1958 data base used to derive an air
standard for barium) the Subcomittee recommends that ODW use its
own data base to develop a standard. The studies that need to be
included in this development primarily involve hypertension in
humans (Wones et al and Brenniraan et al). Based on these studies,
we recommend that the USEPA consider a NOAEL value of 10 mg/L. A
DWEL of 5 mg/L would follow from this choice if an uncertainty
margin of 2 is used. There is no scientific basis for selecting
any particular value between 1 and 5 (derived by using
uncertainty factors of 10 and 2 respectively). However, the 4.7
value used by ODW gives a false impression of precision. The
Subcommittee recommends that only one significant figure be used.
The Subcommittee recommends the addition of a' diagram
showing sources and the proportion of intake of barium from food,
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water and air. In addition, we recommend an illustration of
barium toxicokinetics, including metabolism and excretion (as was
included in the criteria Document for Copper).
A list of more specific detailed comments has already been
sent to the program offices.
Sincerely,
Norton Nelson, Chairman
Executive Committee
Richard A. Grieseraer, Chairman
Environmental Health Committee
Bernard Weiss
Chairman, Metals Subcommittee
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Science revisory Boara
environmental Health
Dr. 3ernaro Weiss [Chair j , Processor, Division of Toxicology, P.O, Box
kBB, Universicy ot Rochester, School of hedictne, Rochester, NY H64Z
(716) 275-3791
ur. nonaia Wyzga [Vice-cnair j , Electric Power Research Institute, 3412
Hillview Avenue, P.O, Box 1041, Palo Alto, California 94303 (415) #55-2577
Dr. Thomas Clacks on, Professor ana Head, Division of Toxicology, University
at Rochester, School or Medicine, Post Office Box kBB, Rochester, New York
14642 (716) 275-3911
Ur, Gary Diamond, Assistant Professor of Pharmacology, Universicy ot
Rochester School of iiedicine, Rochester, New York 14642 (716) 275-3250
ur. Phil tnterline [hNVliflOMlEUAL hiALTH UiEiriTEEj, Department of BLostatistics,
Graduate School of Public health, University of Pittsburg, 130 Desoto Street,
Pittsburgh, PA 1i>261 14 12) 624-31) 32
br. Robert Uoyer, Deparcnient of Pathology, Health Sciences Centre, Universicy
of Western Ontario, London, Ontario, Canada N6A5C1
Dr. tiarvin Kuschner, bean, School of Itedicine, Health Science Center,
Level 4, State Universicy or f-ew York, stony Brook, New YorK 11794
(515) 444-208U
Dr. Brooke T. fDssman, Department ot Pathology, The university of Vermont,
I led teal Alumni Building, Burlington, Vermont U5405-QU6B (802) 656-2210
Dr» Gunter Uberdoerster, Associate Professor, hadiation Biology ana
Biophysics Division, Universicy ot Rochester, School ot Uedicine, 4UO
Avenue, Rochester, N.Y. 14642 (716) 275-3W4
Dr. K. Williara Sundernan, Professor of Laboratory hedicine and Pharroacology
and Head, Department: of Laboratory hedicine, University of Connecticut
Health Center, Room C 2021, Farmington, Connecticut 06032 (203) 674-232tf
Executive Secretary
Ur. Kichard Cothern, Executive Secretary, Environmental health Committee,
science Advisory Board [A-IOlt'j, U.S. Environmental Protection Agency,
Washington, D.C. 20460 (202)382-2552
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