REVIEW OF THE SELENIUM HEALTH CRITERIA DOCUMENT

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                                                             PB89-109029
Review of the Selenium
Health Criteria Document
(U.S.) Environmental Protection Agency
Washington, DC
19 jul 88

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' 30277-Iffl
 REPORT DOCUMENTATION
        PAGE
1. REPORT NO.
 SAB-EHC-88-036
 4. THI. end subtrti* Review of the Selenium Health Criteria  Document
    PB89-109029

5. Report Data
   July  19, 1988
 7. Author(»)
   Metals Subcommittee
                                          I. Performing Organization Rapt. No.
 9. Performing Orgrnlntlon Nam* and Addretl
    Environmental Protection Agency
    Science Advisory Board
    499 S. Capitol  Street, SW
    Washington, D.C.    20460   (A101F)
                                          10. Prolect/Task/Work Unit No.
                                          II. Contnct(C) or Qrant(O) No.

                                          (C)

                                          (Q)
 12. Spontorlnf Organization Ntmt ind Address
   Environmental Protection Agency
   401 M STreet, SW
   Washington,  D.C.    20460
                                          IS. Type of Report & Period Covered


                                           Final Report	
                                          14.
 IS. Supplementary Notet
 16. Abstract (Limit: 200 word*)
             Metals   Subcommittee   of  the   Science   Advisory   Board's
       Environmental Health  Committee  has  completed  its review  of  the
       Drinking Water Health Criteria  Document for Selenium.dated December
       1986.    The  review  was  conducted January _14- 15,  19%jT~a"€' the ~StT
       James  Hotel  in  Washington,   D.C.   C^The   Subcommittee  made"  two
       recommendations;  that more  informatio'n was needed in the document
       on the studies on which  the standard is based and that the Drinking
       Water Equivalent  Level  (DWEL)  should be  200 roicrograms/L based on
       an  uncertainty  factor  of  10.    The Committee  observed  that  the
       Environmental Protection Agency for • its  suggested drinking water
       equivalent   level has  chosen a  factor 15  and  are to  be  able  to
       balance the dat?. from Yang  et  al  (1983)   and the  National Academy
       of Sciences 1980  conclusion that the safe range of daily selenium
       intake  if   50   to   200   microgram.    The  Subcommittee  further
       recommended that because the  Yang  et al  study and  the National
       Academy of  Sciences recommendation  plays such an important role in
       the  development  of  the  drinking  water  equivalent  level,  that  more
       detail be more redefined concerning these study.
 17. Document Analysis  a. Descriptors
    Metals Subcommittee/ Environmental Health Committee
   b. ld*ntifl«r(/Op*n.Cnd*d Terms
   c. COSATI Field/Group
 II. Availability Statement
                             19. Security Claaa (Thlt Report)
                                                                         21. No. of Pa»t
                                                  20. Security Claaa (Thlt Pafa)
(See ANSI-Z39.18)
                                    See Instructions on Ravers*
                                                   OPTIONAL FORM 272 (4-77)
                                                   (Formerly NTIS-35)
                                                   Department of Commerce

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               UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                          WASHINGTON. D.C.  20460


                          July 19,  1988
                                                            OFFICE or
                                                         THE ADMINISTRATOR
                                                         SAB-EHC-88-037
Honorable Lee M. Thomas
Administrator
U.S. Envorinmental Protection Agency
401 M Street, S.W.
Washington, D.C.  20460

Subject: Science  Advisory Board's review  of the SELENIUM  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 Selenium dated
December 1986^'The review was conducted January 14-15, 1988 at
the St. James Hotel in Washington, D.C. The Subcommittee made
two recommendations; viz, 'that more information was needed in the
document on the studies on which the standard is based and that
the DWEL should be 200 micrograms/L based  on an uncertainty
factor  of 10.
         conclusion  in the  criteria document that the Drinking
Water Equivalent Level  (DWEL) should be 107 micrograms/L is based
mainly on the Yang et al  (1983) study and the National Academy of
Sciences (HAS) 1980  conclusion that the safe and adequate range
of daily selenium intake  is 50-200 micrograms.  One justification
for setting the DWEL at this level is that drinking an average of
2 liters per day would provide close to the upper limit of 200
micrograms per day.  To arrive at this conclusion it was
necessary to set the uncertainty factor at 15, a somewhat unusual
value but the only one that would allow both the use of the Yang
et al study and also give an allowable intake close to the upper
limit of the NAS recommendation.

     The report properly  focuses on the selenium dilemma: the
apparently narrow margin  between minimal daily intakes required
to maintain health and intakes associated with toxicity. The
primary source of data for  establishing the DWEL is the report of
Yang et al (1983) .   The Subcommittee recommends that this report
be discussed at greater length because of the reliance placed
upon it.  For example, the  authors discuss two areas labelled as
high selenium areas.  In  one, selenosis was common in livestock
and toxic signs were apparent in humans.  In the other, selenosis

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"has  naver  been  reported.   In the tables,  however,  the first area
 is seen to be associated with hair and blood levels about eight
 times  higher that  measured in the second.  If 3.2  mg/day of
 selenium is estimated as the LOAEL, based or. the first area, then
 400  ug/day would represent a level below the NOEL.  To be
 consistent, then,  the language in the document should reflect the
 concept that the National  Academy of Scieces figures may
 overestimate the uncertainty margin.  Morever, even in high
 selenium areas, drinking water seems to be an insignificant
 contribution to total intake.  If Yang et al are correct in their
 assertion that  the ratio of toxic to minimal blood levels is
 about 16,  a figure not too deviant from the NAS value, then the
 uncertainty factor could be set to 5-10 without compromising
 safety and without jeopardizing a possibly useful source of this
 essential element.  Also,  the 70 kg standard EPA human is
 probably not representative of the Chinese population, another
 margin in the uncertainty  calculation.

      Because the Yang et al study and the NAS recommendation play
 such an important role in  the development of the DWEL, it is
 recommended that more detail be provided regarding the studies.
 The  Yang et al  study is not clearly described in the criteria
 document and it is not clear what the minimum daily  intake  of
 3200 micrograms/day  (LOEL) used in deriving the DWEL refers to.
 Does the study deal with individuals or geographic areas?   How
 many people were involved? How was selenium intake  measured?
 Also more information is  needed on how the NAS arrived at its
 recommendation of 50-200 microgram daily intake value.

      A second recommendation  is that the USEPA consider  raising
 the  DWEL to 160 micrograms/L by using an uncertainty factor of  10
 instead of 15.   Rounding off to one significant figure could lead
 to a DWEL of 200 micrograms/L.  The reasons for this are as
 follows:
      1.  In the Yang et al study the LOEL was 3200 micrograms per
 day  and no lower values have been  reported.            !

      2.  A statement on page VI-30 that  chronic human ingestion
 of 200 micrograms per day  may be related to increased incidence
 of symptoms is  not supported by any of the data presented  other
 than the NAS report.

      3.  A daily intake of 214 micrograms  (107 micrograms/L x  2
 L/day) is too close to the value needed  for human nutrition (50-
 200  micrograms  per day) and too  far from the  lowest  value  at
 which human symptoms occur.

      4.  There is little or no  evidence  for proposed human health
 effects such as cancer or teratogenic  effects.  Selenium (SeS2+)
 is not regarded as a human carcinogen.

      5.  Uncertainty factors should reflect  likely beneficial
 effects as well as harmful effects.   There  is limited evidence
 that selenium deficiency  is related to cancer and perhaps
 cardiovascular disease.

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Sincerely,
Norton .Nelson,  Chairman
Executive Committee
Richard A.  Griesemer, Chairman
Environmental Health Committee
Bernard Weiss,  Chairman
Metals Subcommittee

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                            !:e:als b'ubcemr.iccee
Dr. Bernard \ieiss  [Chair], Professor, Division of Toxicology,  P.O.  Box
KBB, University or Rochester, School of Medicine, Rochester, MY  14642
(716) 275-3791

Dr. Ronald Wyzga [Vice-chair], Electric Power Research Institute,  3412
Hillvieu Avenue, P.O. Box  1041, Palo Alto, California 94303 (415)  855-2577

Dr. Thomas Clarkson, Professor and Head, Division of Toxicology,  University
ot Rochester, School of lledicine, Post Office Box RBB, Rochester,  New York
14642 (716) 275-3911

Dr. Gary Diamond,  Assistant  Professor of Pharmacology, University ot
Rochester School of Medicine, Rochester, New York 14642 (716)  275-5250

Dr. Phil Enterline [LNVIKOMIENTAL HEALTH CCttllTTEE], Department of Biostatistics,
Graduate School of Public  health, University of Pittsburg, 13U Desoto Street,
Pittsburgh, PA  15261   (412)  624-3032

Dr. Robert Goyer,  Department  of Pathology, Health Sciences Centre, University
of Western Ontario, London,  Ontario, Canada N6A5C1
                                       •                                          •
Dr. liarvin Kuschner, Dean, School of lledicine, Health Science Center,
Level 4, State University  of New York, Stony Brook, New York 11794
(516) 444-208U

Dr. Brooke T. Mossman,  Department of Pathology, The University of Vermont,
Medical Alumni Building, Burlington, Vermont 05405-0068 (802) 656-2210

Dr. Gunter Oberdoerster, Associate Professor,  Radiation Biology and
Biophysics Division, University of Rochester, School of Medicine, 400  ,
Elmwood Avenue, Rochester, N.Y. 14642  (716) 275-3804

Dr. F. William Sunderman,  Professor of Laboratory tiedicine and Pharmacology
and head, Department of Laboratory Medicine, University of Connecticut
Health Center, Room C 2021,  Farmington, Connecticut 06032  (203) 674-2328

Executive Secretary

Dr. Richard Cothern, Executive Secretary, Environmental Health Committee,
Science Advisory Board  [A-101F], U.S.  Environmental Protection Agency,
Washington, D.C. 20460  (202)382-2552

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