United States
                     Environmental Protection
                     Agency
                     Research and Development
 Environmental Research
 Laboratory
 Duluth MN 55804
•EPA-600/S3-83-094  Dec. 1983
&ER&          Project  Summary
                     Environmental  Levels  of  PCB  in
                     Great  Lakes   Fish
                     C. P. Straub and J. M. Sprafka
                      This report  reviews and evaluates
                     previously  reported  PCB  levels  in a
                     variety of fish sampled from various
                     locations in the  Great Lakes.  Higher
                     concentrations in fish appear to be
                     related to near-shore sampling where
                     higher exposure to bottom sediments
                     occurs to the flora and fauna compris-
                     ing the food chains for the specific fish
                     collected.  Highest concentrations of
                     PCBs were found in lake trout and fat
                     trout taken from Lake Superior and in
                     fish collected from  the lower  end of
                     Lake Michigan.  There is a need to
                     identify past and/or present sources
                     contributing PCB contaminants to the
                     off-shore areas as well as to identify
                     major sources of runoff contributing
                     PCBs to the waters of the Great Lakes
                     system. Additional information as to
                     food-chain  constituents is  needed to
                     more rapidly assess prey-predator rela-
                     tionships in the various regions of the
                     system.
                      This Project Summary was developed
                     by EPA's Environmental Research Lab-
                     oratory, Duluth, MN, to announce key
                     findings of the research project that is
                     fully documented in a separate report of
                     the same title (see Project Report order-
                     ing information at back).

                     Introduction
                      The intent of this review was to identify,
                     based on available data reported to us,
                     the  major species of fish  contributing
                     PCBs to the human diet and the major
                     sources of  contamination.  This review
                     first identified levels of contamination by
                     given sampling area  in samples of lake
                     trout in Great Lakes waters, since this
                     species was most extensively studied; it
                     then identified levels by location for other
                     species of fish which form part of the
 human diet or may serve as food sources
 for fish at higher trophic levels. Our
 primary concern was for human exposure,
 even  though  we fully recognized  the
 importance of a total ecological systems
 approach,  particularly with  respect to
 predator-prey relationships. In fact, the
 latter are necessary to fully understand
 and appreciate the potential for human
 exposure through ingestion of fish. One
 other facet that is not directly considered
 in this review is the potential for infant
 exposure to PCBs through breast feeding
 and subsequent accumulations of these
 agents in fatty tissue.
Conclusions
  The  following  conclusions  may be
drawn  based upon the data available to
the authors and the assumptions referred
to in the text.

  1. There is a dearth of information on
     PCB levels in many species of fish
     collected from various locations. In
     many instances, only one or two
     samples were collected annually or
     biennially.

  2. Where more data were available for
     specific fish from given locations, it
     was demonstrated that the PCB
     concentrations reported varied in a
     log-normal manner.

  3. Based upon  data  reported for fish
     collected from certain areas of Lake
     Superior, the concentrations gener-
     ally  were lower,  whereas near-
     shore  samples included  in these
     same areas showed higher bottom
     mud and sediment concentrations
     in the near-shore areas.

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   Recommendations
     1. All subsequent investigations of fish
       and  other sources of PCBs in the
       Great Lakes should be coordinated
       through   a   central  organization
       which can specify the kinds of fish to
       be collected, numbers of fish, and
       locations for sample collection.

     2. There is a greater need for reporting
       the portion of the fish examined (i.e.,
       the total fish  or edible fraction) to
       provide a better base for comparing
       samples.  Similarly, methods used
       for analysis should be reported and
       a  uniform system of quality control
       should   include  all   laboratories
       carrying  out  these  studies.  The
       specific standard used for  estima-
       ting  the  PCB concentration should
       be indicated, and information on the
       actual  isomers identified should be
       reported.

     3. With the isolation of areas of higher
       fish  contamination,  a concerted
       effort should  be  made  to  indicate
       whether such contamination levels
       reflect current discharges of PCBs
       or sources that  have accumulated
       over time.

     4. Stomach contents of the fish caught
       should be examined to identify feed-
       ing habits in the various parts of the
       lake  system during  different
       seasons of the year.

   Species of Fish Sampled
     The most extensive data available for
   study  were on lake  trout, but  data  in
   variable number were  reported for fat
   trout,   carp,   catfish,   yellow   perch,
   whitefish, walleye, sucker, red sucker,
   black crappie,  brown bullhead,  herring.
        fresh water drum, bloater, burbot, brown
        trout,  rainbow  trout,  muskie, salmon,
        Chinook salmon, cisco, and smelt. Similar
        species were not sampled from all sites,
        probably due to the fact that all species
        were  not  found  at all locations. The
        species of most interest are those that
        have  been  identified  as  major  food
        sources. These, in order of preference as
        indicated by preliminary data from the
        epidemiological questionnaire on eating
        habits  of  commercial  fishermen,  are
        yellow perch, lake whitefish, lake herring,
        and lake trout.
Results
  Data are presented in the form of semi-
logarithmic plots of PCB  concentration
(log scale) vs. length (arithmetic scale) or
weight (wet) (log scale) vs. length (arith-
metic scale); as logarithmic plots of PCB
concentration (log scale) vs. weight (wet)
(log scale); and as logarithmic probability
plots of PCB concentrations. In addition,
fish  body burden  (mg) vs. fish  weight
(grams) was plotted on log-log paper and
demonstrated a better linear relationship
than that reported by others using an
arithmetic plot.
          C. P. Straub andJ. M. Sprafka are with the School of Public Health, University of
            Minnesota, Minneapolis, MN 55455.
          W. R. Swain is the EPA Project Officer (see below).
          The complete report, entitled "Environmental Levels of PCB in Great Lakes Fish,"
          {Order No. PB 83-264 481; Cost: $10.00, subject to change) will be available only
            from:
                  National Technical Information Service
                  5285 Port Royal Road
                  Springfield,  VA 22161
                  Telephone: 703-487-4650
          The EPA Project Officer can be contacted at:
                  Environmental Research Laboratory
                  U.S. Environmental Protection Agency
                  6201 Congdon Blvd.
                  Duluth.'MN 55804
                                                     
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