1994 State of the Lakes Ecosystem
            Conference
        Background Paper
       Toxic Contaminants
             August 1995
          Environment Canada
United States Environmental Protection Agency
           EPA 905-R-95-016

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State of The Lakes Ecosystem Conference

            Background Paper
     TOXIC CONTAMINANTS
                  IN
       THE GREAT LAKES
             David De Vault
              Paul Bertram
     Great Lakes National Program Office
     U.S. Environmental Protection Agency
             Chicago, Illinois
              D. M. Whittle
        Fisheries and Oceans Canada
             Ottawa, Ontario

              Sarah Rang
    Environmental Economics International
             Toronto, Ontario

              August 1995

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Table of Contents

EXECUTIVE SUMMARY	1

1.0 INTRODUCTION	3

2.0 TRANSPORT AND FATE	7

3.0 CONTAMINANT LOADINGS	9

4.0 AMBIENT CONCENTRATIONS AND TRENDS	13

  4.1 Concentrations and Trends in the Water Column	13
  4.2 Concentrations and Trends in Open Lake Fish	14
  4.3 Concentrations and Trends in Herring Gulls	21
  4.4 Atmospheric Concentrations	21

5.0 LINKAGE WITH OTHER ECOSYSTEM COMPONENTS	 	23

6.0 KEY ISSUES TO CONSIDER	25

7.0 REFERENCES	27

Appendix A: Existing Monitoring Programs	29

Appendix B: Descriptions of Contaminants	33

List of Figures		37

Figures	39
Toxic Contaminants - SOLEC Background Paper                                 iii

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                               NOTICE TO READER

These  Background Papers are intended to provide a concise  overview of the status of
conditions in the Great Lakes. The information presented has been selected as representative
of the much greater volume of data.  They therefore do not present all research-or monitoring
information  available.  The Papers were prepared  with  input from many individuals
representing diverse sectors of society.

The Background Papers were first released as  Working Papers to provide the basis for
discussions at the first State of the Lakes Ecosystem Conference (SOLEG) in October, 1994.
Information  provided by  SOLEC discussants  was incorporated into these final SOLEC
Background Papers. SOLEC was intended to provide key information required by managers
to make better environmental decisions.
                                                                                 IV

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Executive Summary
The overall contaminant picture for the Great Lakes has improved dramatically since the mid-
1970s,  with significant declines in  environmental concentrations of  most of  the  critical
contaminants for which data are available.

This is best illustrated with PCBs, for which we  have the  most extensive data base. PCB
concentrations in Lake Superior water declined from 1.73 ng/1 to 0.18 ng/1 between 1978 and
1992. In southern Lake Michigan water column PCB concentrations declined from 1.8  ng/1 in
1980 to 0.2  ng/1 in 1993. These declines are also observed in biota, with concentrations in Lake
Michigan lake trout declining from 22.9 ng/g in 1974 to 2.77 ng/g in 1990. Declines were also
observed  in DDT, 2,3,7,8-TCDD, mirex (in  Lake  Ontario), mercury,  lead,  dieldrin,  and
oxychlordane. Concentrations of HCB and BaP were very low.

While  most contaminants  have declined substantially since first monitored, declines in PCB,
DDT and, possibly, other  organochlorines in Great Lakes biota appear to have ceased or, in
some cases, reversed in  recent years. The reason  for this is  uncertain,  although continued
declines in PCB concentrations in the water columns of Lakes Superior and Michigan suggest
that factors other  than contaminant  loadings are responsible.  One possibility  is that major
changes in the food web,  which were observed concurrent with the slowing and reversals in
contaminant declines, may be responsible. Such changes may alter the pathways that chemical
contaminants follow as they bioaccumulate up the food chain to top predator species. If changes
in the food chain are responsible for the recent trends, we would expect future declines in biota
once the food web stabilizes.

While contaminant concentrations have declined, several water quality objectives and fish tissue
criteria for the protection of human health are still exceeded. PCB concentrations in fish across
much of the basin exceed the IJC objective of 0.1  g/g for the protection of biological resources,
and  exceedences  of state  and provincial  human health criteria result  in fish consumption
advisories for each of the  lakes.  Meeting existing and proposed future objectives will  require
further decreases in contaminant concentrations.
Toxic Contaminants - SOLEC Background Paper

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1.0    Introduction
The Great Lakes have been exposed to a large number and volume of contaminants known to
have an adverse impact on plant and animal life, including humans.  Scientists have detected 362
contaminants in the Great Lakes ecosystem, including 32 metals,  68 pesticides and 262 other
chemicals. About one-third of the chemicals found in the Great Lakes can have acute or chronic
toxic effects (DC 1991).

Under the Great Lakes Water Quality Agreement (GLWQA), both the United States and Canada
are committed to restoring and maintaining the chemical, physical, and biological- integrity of the
Great Lakes Basin ecosystem.  As part of this commitment, the Parties agree that "the discharge
of toxic substances in toxic amounts be prohibited and the discharge of any or all persistent toxic
substances be virtually eliminated" (US and Canada 1987).

A variety of criteria have been used in past studies to develop lists of toxic chemicals relevant to
the Great Lakes.  Each list has been developed with a particular purpose in mind, involving the
types of information  desired, the critical values associated with the criteria, and the relative
importance of the criteria.  For the purposes of this review, we will focus on the list of 11 critical
pollutants identified by the International Joint Commission (IJC) (Table 1).  These pollutants
have been selected because they are persistent and bio-accumulative, may interact with other
chemicals to produce synergistic, additive or antagonistic effects, are known to cause detrimental
effects on biota and/or human health, and are present in the Great Lakes. Table 2 includes some
selected criteria or action levels for these compounds in different media.
Table 1: Critical pollutants in the Great Lakes


  2,3,7,8- TCDD (tetrachlorodibenzo-p-dioxin)    DDT and metabolites
  2,3,7,8- TCDF (tetrachlorodibenzofuran)       Alkylated Lead
  Total PCBs                               Mirex
  HCB (Hexachlorobenzene)                   Toxaphene
  Mercury                                 Dieldrin
  Benzo(a)pyrene


Source: DC (1991)
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Table 2.   Selected criteria, action levels or guidelines for critical pollutants in the Great
Lakes

 Contaminant   US FDA (I)  Health Canada    LTC (3)     ITC (4)      MYBQH     OMEE (6)
                             O)                                       15)
2378-TCDD
DDT
PCB
Aldrin/
Dieldrin
Toxaphene
Mirex
Mercury
Lead
25pg/g
5ug/g
2ug/g
0.3 ug/g

5ug/g
0.1 ug/g
1 ug/g

2Qpg/g
5 ug/g
2 ug/g



0.1 ug/g
0.5 ug/g

                                               0.003 ug/1   1 ug/g (a)
                                                           0.1 ug/g (a)
                                               0.001 ug/1   0.3 ug/g
lOpg/g
5 ug/g
2 ug/g
0.3 ug/g
5 ug/g in fish
0.001 ug/1
0.001 ug/1
0.008 ug/1
Ld
0,2 ug/1
25ug/I

Ld
0-5 ug/g


0.1 ug/g
1 ug/g

0.008 ug/1
0.001 ug/1
0.2 ug/1
X
Ld  Less than detectable.
X Between 1 and 5 ug/1 depending on water hardness.
a  Whole fish.

(1) US Food and Drug Administration  action levels in edible portions of fish for regulation of interstate
commerce.
(2) Health Canada consumption guidelines for edible portions of fish.
(3) (4) International Joint Commission objectives for protection of aquatic life and wildlife.
(5) New York State Department of Health, criteria for edible portions of fish.
(6)  Ontario Ministry of Energy and  Environment water  quality guidelines for  protection  of human
consumers of fish.
It is important to recognize that the IJC list of 11 priority pollutants is not the only list that has
been compiled in order to address persistent toxic substances in the  Great Lakes.   Table 3
includes a list of the more commonly  targeted pollutants in the Great  Lakes and some of the
programs through which they are being addressed.

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Table 3:  Targeted pollutants of the Great Lakes
  Aldrin (157)                              Benzo(a)pyrene (13578)
  Chlordane (1 2 3 6 7)                       Copper (12 3)
  DDT and metabolites (123567)             Dieldrin (12367)
  Furans, including 2,3,7,8-TCDF (1357)       Heptachlor (123)
  Heptachlorepoxide(l 3)                     Hexachlorobenzene (1 2 3 5 6 7)
  Alkylated Lead (13457)                   Hexachlorocyclohexane (1 3 8)
  6 Hexachlorocyclohexane (1 3 8)              Mercury (1234567)
  Mirex (1357)                             Octachlorostyrene (1367)
  Polychlorinated biphenyls (123567)         2,3,7,8-TCDD & other dioxins (123567)
  Toxaphene (123567)
References:     1 = GLWQA Annex One, list 1 (173 total pollutants in list)
              2 = GLWQI guidance list of 33 pollutants
              3 = LAMPS critical pollutants lists (Lake Michigan 15 total)
              4 = Pollution Prevention (Industrial Toxics Project, 17 total)
              5 = Eleven Critical Pollutants (UC, 1985)
              6 = Lake Superior Lakewide Management Plan (9 total)
              7 = Canada-Ontario Agreement Tier I list of 13 virtual elimination contaminants
              8 = Canada-Ontario Agreement Tier n list of 26 (including 17 PAHs)
This paper will review the current data on toxic contaminants found in the air, water, sediments,
fish and wildlife of the Great Lakes with emphasis on the IJC critical pollutants.  The review
primarily surveys information available to December 1993.  The goal of this review is to provide
sufficient information on contaminant levels and trends to stimulate discussion among interested
parties, and to assist future decision-making on Great Lakes environmental quality issues.  The
paper has been organized into discussions of 1) transport and fate; 2) loadings; 3) concentrations
and trends in various media; 4) linkage issues to other stressors and to environmental effects; and
5) knowledge  gaps and key issues in dealing with persistent toxic chemicals in the Great Lakes.
Because of space limitations, we have not attempted to include all available  data, but have,
instead,  attempted  to  bring together those data which  describe the status  and  trends  of
contaminants from a Great Lakes Basin perspective.
Toxic Contaminants - SOLEC Background Paper

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2.0   Transport and  Fate
Contaminant transport and fate is complex.  Chemical contaminants enter the Great Lakes from
a  variety  of  sources, including  direct  point  source  discharges,  tributary  loadings,  and
atmospheric deposition.   These loadings originate from both current and past releases to the
environment.  For example, tributaries discharge not only chemicals currently in use, but also
those which were discharged in the past and have accumulated in their sediments.  A large
proportion of the present tributary loadings of chemicals such as PCB, DDT, dieldrin, and mirex
are probably the result of contaminated tributary  sediments, rather than current discharges.
Atmospheric deposition includes chemicals discharged to the atmosphere  from  point and non-
point sources, as well as chemicals that  are volatilized  from other  aquatic  and terrestrial
ecosystems, or from the  Great Lakes themselves.   Contaminants  reaching the lakes via the
atmosphere may have traveled long distances through a series of steps wherein they are released,
deposited on terrestrial or aquatic systems, then volatilized  and returned to the atmosphere.
During each atmospheric residence, they are moved further from the original source.

While in the lake system,  contaminants move between media.  They sorb to particles, primarily
algae, where they may  be bioaccumulated up the food chain, or  sink toward the bottom
sediments.   Contaminants on sinking particles may be effectively removed from the system by
burial in the bottom sediments, or they may be returned to the water column to repeat the cycle.
Both the bottom sediments and the atmosphere represent boundaries across which contaminants
are exchanged, in both directions.  The relative magnitude  of these processes can be seen in a
recent PCB mass budget for Lake Superior (Table  4). Atmospheric deposition, tributaries and
"other sources" contributed approximately 307 kg to the water column. This joined the -10,100
kg  already present  from  previous inputs.  Of  this mass, approximately  3,000 kg sorbed to
particles  and began the process of sedimentation and burial. However, nearly all (2,890 Kg) of
this was returned to the water column, either prior to reaching the bottom sediments, or from the
bottom sediments. This budget indicates that, in Lake Superior, very little of the  PCB mass was
permanently buried  in the sediments and that the atmosphere was the primary route by  which
PCBs left the Lake,  with  approximately  1,900 kg volatilizing. Sedimentation and burial would
be expected to be a more important removal pathway in a shallower, more productive, lake such
as Erie. Table 4 also illustrates that PCBs were declining in Lake Superior with approximately
307 kg entering and over 2,000  kg (1,900 kg to the atmosphere and  110 kg to  the sediments)
leaving the water column in 1986.
Toxic Contaminants - SOLEC Background Paper

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Table 4. Approximate PCB Mass Budget tor Lake Superior Water Column in 1986

                             Inputs (kg/yr.)          Outputs (kg/yr.)
 Atmosphere                  157                   1900
 Tributaries                  110                   60
 Other Discharges             40                    0
 Bottom sediments             2890                  3000

From Jeremiasonetal, (1994).

Typically, metals and high molecular weight organic compounds, such as chlorinated dioxins,
furans  and higher chlorinated PCBs will ultimately be deposited in the sediments.  Lower
molecular weight organic chemicals (such  as lower chlorinated PCBs) will volatilize to the
atmosphere. While Table 4 illustrates the inputs and movement of PCBs in Lake Superior for a
single year (1986), Table 5 provides estimates for the long term fate of PCBs and lead for each
of the Great Lakes.
Table 5. Estimated fate of PCB and Pb in the Great Lakes

               % Volatilized             % to Sediments           % to Outflow

  Late         PCB       PJ>           PGB         Eb          PCB
Superior
Michigan
Huron
Erie
Ontario
87
68
75
46
53
0
0
0
0
0
11
31
19
45
30
99
98
93
90
80
2
1
6
9
17
1
2
1
10
20
From Strachan and Eisenreich (1988)

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3.0   Contaminant Loadings
The term, contaminant loadings, refers to chemicals entering a system from outside sources  via
atmospheric deposition, tributary discharge, as well as point and non point discharges to the
lakes. Of these, atmospheric deposition and tributary discharge are the primary routes by which
chemicals enter the Great Lakes system.

Unfortunately, our estimates of both atmospheric and tributary loadings to most areas of the
Great  Lakes  are  inadequate.   There  are difficulties in measuring  the  low  contaminant
concentrations in  many tributaries which may,  nevertheless, deliver  significant masses of
contaminants over time.  Tributaries may also deliver a large portion of their annual load during
storm events that last only a few hours or  days. Thus tributary loadings studies usually require
intensive, event-related sampling.  Adequate sampling designs are further complicated by
occasional influxes of lake water (flow reversals) into the lower reaches of tributaries due to
weather related conditions.  These factors result in tributary monitoring being very expensive
and, because of the high cost, there are few  reliable estimates.

Estimating  atmospheric loadings  also presents significant  monitoring challenges.  Chemicals
entering the lakes from the atmosphere are delivered through precipitation (rain and snow fall),
as dry particulates, and  by direct gas exchange across  the air-water interface. There  are
difficulties inherent in measuring the parameters necessary  to estimate the contribution of each
of these processes. In addition it is difficult, with  current monitoring networks, to estimate the
local inputs from urban areas.

Previously published estimates of tributary and atmospheric loadings to the Great Lakes are
presented in Table 6. These estimates suffer from several  significant short comings. Tributary
estimates may be quite old, based on  very limited data, and were calculated using  different
methods. As a result the error ranges are large. The-atmospheric estimates are consensus values
derived from several data bases in 1992 (Eisenreich and Strachan 1992). They are also subject to
substantial error. The reader is strongly advised to consult the original reference prior to use
of anv of the values in Table 6.
Toxic Contaminants - SOLEC Background Paper

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Table 6.  Tentative estimates of selected critical contaminant loadings to the Great Lakes
(kj/yr.). (a)

Chemical
TCDD
TCDF
PCBs
Hg
BaP
Pb

Source
Tributary
Atmosphere (1)
Tributary
Atmosphere (1)
Tributary
Atmosphere (1)
Tributary
Atmosphere (1)
Tributary
Atmosphere (1)
Tributary
Atmosphere (1)

Superior
NA
0,01 9(w)
NA
0.37(w)
28(2)- 11 0(4)
157
124(3)
2181
NA
115
NA
67055

Michigan
NA
0.014(w)
NA
0.27(w)
650(2)
114
NA
1568
NA
84
NA
25920
LAKE
Huron
NA
0.014(w)
NA
0.27(w)
236(2)
114
NA
1584
NA
1584
NA
10488

Erie  
0.1-0.5 (2)
0.0065(w)
0.1-0.'5(2)
0.1 3(w)
741(2)
53
2584(3)
723
425(2)
723 .
NA
96574

Ontario
NA
0.0052(w)
NA
0.10(w)
609(2)
42
NA
568
148(2)
568
NA
47610
NA No data available for estimate.

(a)  These estimates  are partially based on old or limited data,  and they  should be  viewed as only
       approximations of current loadings. The reader is strongly  advised to consult the original source
       prior to use.
(w) Based on wet deposition only

Sources:
 (1) Eisenreich and Strachan (1992)
 (2) USEPA estimate
 (3)UC(1993)
 (4) Jeremiason et. al (1994)
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Indirect Loadings Measurements

While direct measures of contaminant loadings are desirable, knowledge of the transport and fate
of these chemicals allows substantial information to be derived from indirect means.  Dated
sediment cores reflect historical contaminant loadings because mixing and mobility processes do
not generally occur rapidly enough to erase contaminant profiles in the sediments-. Recent studies
of dated sediment  cores from depositional areas in Lakes Michigan and Ontario show the
declining concentrations of PCB and total DDT, which have resulted from regulations on the
manufacture and use of these contaminants (Figure 1).  Similarly, sediment cores from Lakes
Superior, Michigan and Ontario indicate that loadings of both Pb and Hg have been declining for
several years (Figure 2).

Sediment core data may also be compared with atmospheric deposition estimates to calculate the
relative importance of atmospheric and tributary loadings.  Sitarz et al. (1993) used sediment
fluxes and atmospheric deposition data from the International Atmospheric Deposition Network
(IADN) to calculate the approximate atmospheric contribution to Cd, Hg and Pb loadings (Table
7). While these are approximations, they demonstrate the importance of atmospheric loadings to
the upper Great Lakes.  These types of data may allow limited resources to be efficiently
directed toward remedial  or  regulatory programs in the absence of direct measurements of
loadings,

Table 7.   Approximate  relative contribution of atmospheric loadings to total loads (%
atmospheric) based on three data sources.   	;      	

                     Cd                   Hg                  Pb

  Lake Superior       >90                   >90                  >90
  Lake Michigan      -50                   >90
  Lake Ontario        <50
Adapted from Sitarz et al. (1993)
Comparison of sediment data from differing environments within the Great Lakes Basin may
provide additional information on sources of loadings.  It has long been thought that the primary
source of the complex pesticide, toxaphene, was long  range atmospheric transport from the
southeastern US.  Recent sediment data for toxaphene have raised questions regarding this.  In
Figure 3, toxaphene deposition rates are displayed from three sites in the Great Lakes Basin:
northern  Lake Michigan, Lake Superior, and an inland lake in the  Apostle Islands of Lake
Superior. The Apostle Islands site is a small lake, without tributaries, that is only influenced by
atmospheric loadings. Notable is the lack of significant decline in toxaphene in sediment cores
from northern Lake Michigan and Lake Superior (the opposite of what we observed for PCB,
DDT, Hg and Pb).).  Efforts are currently underway to discover the sources of this contaminant.
Toxic Contaminants - SOLEC Background Paper                                         11

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Because of the technical difficulties and high cost of load monitoring, it is -unlikely that agencies
will be able to establish and maintain intensive load monitoring programs across the entire Great
Lakes Basin, and operate them for extended periods of time. Fortunately, the behavior and fate
of contaminants is predictable. Thus, intensive monitoring efforts on specific portions of the
Great Lakes ecosystem  may allow the construction  of models capable of predicting both the
changes in concentrations in the lakes resulting from changes in loadings, and-given ambient
concentrations, calculating the loadings. Such efforts will improve our ability to launch targeted
contaminant track down and remediation efforts. Brief descriptions of some of the monitoring
and modeling programs currently underway presently in place are presented in Appendix A.
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4.0  Ambient Concentrations and Trends
4.1  Concentrations and Trends in the Water Column

The concentrations of IJC Critical Pollutants in the water column are quite low and the available
data are limited. Table 8 contains recent estimates of the total water column concentrations of
these chemicals in each lake. The data represent studies undertaken between 1986 and 1991 by
Environment Canada, USEPA and researchers funded by the USEPA.
Table 8. Recent contaminant concentrations in the Great Lakes waters  (ng/1).
                                                 LAKE
Chemical
PCB
p,p'-DDE
Dieldrin
HCB
B(a)P
Superior
0.18(1)
<0.06(3)
0.26(3)
<0.04(3)
<0.46(3)
Michigan
0.20(2)
NA
NA
NA
NA
Green
Bay
17.1(4)
NA
NA
NA
NA
Huron
0.9(3)
<0.06(3)
0.32(3)
0.07(3)
<0.46(3)
Georgian
Bay
0.69(5)
0.03(5)
0.35(5)
0.04(5)
NA
Erie
1.22(3)
<0.06(3)
0.38(3)
0.05(3)
<0.46(3)
Ontario
1.20(3)
<0.06 (3)
0.28(3)
0.04(3)
<0.46(3)
NA=No data available.

(1) Jeremiason and Eisenreich (1994)
(2) USEPA, Great Lakes National Program Office, unpublished data
(3)L'ltalien(1993)
(4) De Vault (1992)
(5) Stevens and Neilson (1989)
The technology required to measure contaminants at the trace concentrations found in the water
column of the Great Lakes has become widely available only recently.  As a result, meaningful
Toxic Contaminants - SOLEC Background Paper
13

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trend data are limited. However, research studies conducted for the USEPA and the US National
Oceanographic and Atmospheric Administration by the University of Minnesota and University
of Wisconsin  provide insight into water column trends for PCBs (Table 9).   Total PCB
concentrations in the Lake Superior water column declined from 1.73 ng/1 in 1978 to 0.18 ng/1 in
1992.  Comparable data from Lake Michigan are only available  for the  open waters of the
southern Basin.  These data indicate substantial declines from 1.8 ng/1 in  1980 .to 0.2 ng/1 in
1992 (Table 9).
Table 9.  Total PCB Concentrations in lakes Superior and Michigan (mean ng/1).
  Year                     Lake Superior (1)             Lake Michigan
1978
1979
1980
1983
1986
1988
1990
1991
1992
1.73
4.04
1.13
0.80
0.56
0.33
0.32

0.18


1.8(2)




0.4(3)
0.2(4)
(1) Jeremiason et al. (1994)
(2) Swackhamer and Armstrong (1987)
(3) Swackhamer and Pearson (1994)
(4) USEPA, Great Lakes National Program Office, unpublished data
4.2  Concentrations and Trends in Open Lake Fish

Contaminant concentrations in fish from the  open waters of the  Great Lakes have been
monitored for over 20 years, and provide one  of the most extensive data bases on trends in
environmental contaminants available anywhere in the world. These programs were originally
implemented due to concern over the effects of contaminants on fish  consumers (both wildlife
and human) and on the fish themselves, and because the technology was not available to directly
measure the trace levels present in the water column.  It was assumed that top predator fish
species would,  over  the  long  term, reflect  changes in water column  concentrations,  thus
providing a cost effective surrogate to expensive water column monitoring. They are continued

                                                                                  14

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across the Great Lakes today for similar reasons, i.e., cost effectiveness and continuing concerns
about human and wildlife health.  Comparison of PCB trends in open lake fish with the available
water column PCB trend data, indicates that, over the long term, trends of contaminants (PCBs)
in fish have followed those in the water column (De Vault  and Hesselberg, 1994) and thus
provide a measure of trends in the Great Lakes ecosystem.

The data below are primarily the result of three monitoring programs. Lake trout and smelt are
monitored by Fisheries and Oceans Canada, using individual whole lake trout of a consistent age
(4+) and. composites of smelt. Lake trout and walleye  (Lake Erie only) from US waters are
monitored  cooperatively  by US EPA- Great Lakes  National Program Office, US National
Biological  Service (NBS), and the Great Lakes States. The US program  utilizes whole fish
composite  samples of a consistent size (600-700 mm  lake trout,  400-500 mm walleye). Coho
salmon fillets are monitored in US. waters through a cooperative program involving the Great
Lakes States, US Food and Drug Administration and US EPA- Great Lakes National Program
Office, using five  fish composites of age 2+ coho. These programs are complimentary in that
together  they control  for the  two  primary  variables, other than  exposure,  which  affect
contaminant concentrations within an individual species; age and size. While the data can not be
directly compared across these monitoring programs, the general trends may.

PCBs

Data collected in  southeastern  Lake Michigan provide insight into the  history of PCB
contamination (Figure 5).  PCB concentrations in Lake Michigan lake trout increased from 12.86
ug/g in 1972 to 22.91 ug/g in 1974.  Between  1974 and 1990,  PCB concentrations declined, by
nearly an order of magnitude, to 2.72 ug/g, approximating a first order decay During the period
1977-1990, PCB concentrations declined significantly  in lake trout in the  Lakes Superior,
Huron, and Ontario, and in walleye from Lake Erie (Figure 5), following the same general trend
observed in Lake Michigan.  While there have been substantial declines in  PCB concentration
since the mid 1970s, concentrations have been relatively constant  since the mid 1980s, with the
exception of Lake Ontario, where declines continue through the most recent data available.

PCB trends in coho salmon fillets from Lake Michigan differ somewhat from those observed in
lak& trout.  PCB concentrations in coho fillets declined from 1.9  ug/g in 1980 to 0.38 ug/g in
1983, after which they increased steadily to 1.09 ug/g  in 1992.  Coho salmon  fillets from Lake
Erie declined from 1.07  g/g in 1980 to  0.53 ug/g in  1992. In both lakes,  the decline in PCB
concentrations  in the coho was statistically significant, as was the increase in Lake Michigan
coho PCB concentrations (Figure 6),

The lack of recent decline in PCB concentrations (and DDT, see below) in lake trout and their
increase in coho salmon from Lake Michigan is problematic in light of continued declines in
PCB concentrations in  the water columns of Lakes Superior and Michigan (see section 4.1
Concentrations and Trends in the Water Column).   PCB trends in lake trout from both Lake
Michigan and Lake Superior followed trends observed in the water column very closely through
the mid 1980s after which the rate of decline in fish  began to slow or even  stopped entirely.


Toxic Contaminants - SOLEC Background Paper                                        15

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Because top predators such as lake trout receive over 90 percent of their PCB burden through
food, it is likely that the lack of decline in PCBs in lake trout and walleye, as well as the
increases in coho, are the result of changes in the food chain.   The Great Lakes have been
invaded by numerous exotic species, some of which have the potential to alter food chains in a
manner which could affect contaminant transport to top predator fish species.  If this is the case,
concentrations of contaminants in the fish should begin to decline again, once the effect of the
new species has stabilized in the food chain.

While PCB concentrations in open lake fish have declined dramatically in response to regulatory
activity, concentrations in top predator fish species from all lakes were still well above the DC
objective of 0.1 ug/g (in whole fish) (Table 2) in 1990.
DDT

Declines in total DDT (the sum of DDT plus metabolites) concentrations were noted in Lake
Michigan lake trout as early as the  1970's (Figure 7).  DDT concentrations in Lake Michigan
lake trout declined from 19,19 ug/g  in 1970 to 1.39 ug/g in 1990 following the same pattern of
decline that was observed for PCBs. DDT also declined significantly over the period of record in
fish from  Lakes Superior, Huron,  Ontario and Erie.  As was observed for PCBs, DDT
concentrations appear to have leveled off in Great Lakes fish in recent years. Little significant
change  has been observed in DDT  concentrations in lake trout from Lakes Superior or Lake
Michigan since the  mid 1980s. Similarly  there has been little  change  in fish from Lake Erie
since the early 1980s  (Figure 7).  Only in Lake Huron lake trout is total DDT Continuing to
decline at approximately the same rate over the period of record.

DDT concentrations in fillets from Lake Michigan  coho salmon (Figure 8) follow the pattern
observed for PCBs.  That is,  statistically  significant declines from  1980 through  1983, then
statistically significant increases through 1992.  Levels of DDT in  Lake Erie coho declined
significantly from 1980 through 1984, after which there was no statistically significant change.
The strong correlation between trends in DDT and PCB suggests that changes in composition of
the food web may be at least partly responsible for the lack of recent declines, and for observed
increases in contaminant concentrations in the fish.

In spite of dramatic declines in DDT concentrations in Great Lakes fish, they still exceeded the
IJC objective of 1.0 ug/g (Table 2) in Lake Michigan, and were  very near the objective in Lake
Ontario.
Dieldrin

Dieldrin concentrations in Lake Michigan lake trout increased from a mean of 0.27 ug/g in 1970
to 0.58 ug/g in 1979, then they declined to 0.17 ug/g in 1986 and 0.18 ug/g in 1990 (Figure 9).
While concentrations varied between lakes, the pattern observed in Lake Michigan was also

                                                                                     16

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observed in Lakes Superior, Huron and Ontario, i.e., a general decline, but with peaks in 1979
and 1984. In Lake Erie walleye, mean dieldrin concentrations decreased from 0.10 ug/g in 1977
to 0.04 ug/g in 1982, then increased to 0.07 ug/g in 1984, then declined again to 0.03 ug/g in
1990.  Between 1979 and 1990, mean dieldrin .concentrations declined significantly in the top
predator fish from Lakes Michigan, Huron and Erie (Figure 9).

Dieldrin concentrations are well below the IJC objective of 0.3 ug/g in whole fish.
Toxaphene

Unlike PCBs and DDT, which are typically highest in Lakes Michigan and Ontario and lowest in
Lake Superior, toxaphene concentrations in lake trout are highest in the fish from Lakes
Michigan and Superior (1.91 ug/g and 1.27 ug/g, respectively, in 1990) and lowest in Lakes Erie
and Ontario (Figure 10).  It is currently the dominant contaminant in Lake Superior lake trout,
and  it is second to PCBs in Lake Michigan lake trout.  Significantly  lower (<0.5  ug/g)
concentrations were found in walleye and lake trout from Lakes Erie and Ontario.

While toxaphene in fish tissue has not been measured long enough to detect trends, limited
sediment data suggest that toxaphene may not be declining in Lake Michigan and Superior (see
Section 3, Contaminant Loadings).
TCDD and TCDF

There has been substantial monitoring of Great Lakes fish for 2,3,7,8-TCDD and 2,3,7,8-TCDF.
However, with the exception of Lake Ontario, these parameters have not been routinely included
in open lake trend monitoring programs because of the low concentrations and the high cost of
analysis. Tables 10 and 11 contain a subset of the open lake data. Because the sampling location,
age and size of fish analyzed vary between studies, the data can not be directly compared
between years. However, the data sets are comparable across lakes within a given year, and the
1978 and 1988 data bases are comparable both between years and across lakes.

Lake Ontario lake trout have the highest concentrations of 2,3,7,8-TCDD and Lake Superior the
lowest.  Because data were collected using differing strategies, these data are of limited use in
detecting trends. However, the 1978 and 1988 samples  were collected and analyzed following
similar protocols. The results suggest a basin wide decline between 1978 and 1988.
Toxic Contaminants - SOLEC Background Paper                                        17

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Table  10.  2,3,7,8-TCDD  Concentrations  in  whole  lake trout from Lakes Superior,
Michigan, Huron and Ontario, and in walleye from Lake Erie, pg/g (*)

                                            Lake

 Year          Superior       Michigan      Huron         Erie           Ontario

 1978(1)       2.19           7.37           22.2           2.9            78.6
 1984(2)       1.0            4.7            8.6            1.8            48.9
 1988(1)       Ld      -      2.83           19.7           Ld.            22.1
 1990(3)       2.8            Na            Na            Na            44.3
 1992 (4)       2.29           2.95           2.92           2.32           40.36

(*) Data are not comparable between years and the original reference should consulted prior to use.
Na=Not analyzed
Ld = below limit of detection

(1) USEPA, Great Lakes National Program Office, unpublished data.
(2) De Vault etal.( 1989)
(3) Whittle etal. (1992)
(4) Fisheries and Oceans Canada, unpublished data.

2,3,7,8-TCDF concentrations in these same samples are presented in Table 11. Czuczwa and
Kites (1984, 1986) suggest that the atmosphere is the primary route by which these chemicals
reach the Great Lakes. There is also evidence for localized sources, i.e., the high concentrations
reported for Lake Ontario.  De Vault et al. (1989) also found evidence for both localized and
broad  homogeneous (probably atmospheric) sources  of both dioxins and  furans  in  Lake
Michigan  lake trout.  Localized sources were found to be impacting portions of Lake Michigan,
possibly because of PCDFs associated with PCB contamination in Green Bay. Comparison of
the 1978 and 1988 data suggest that TCDF concentrations declined in fish from all five Great
Lakes during that time interval.

Table  11.  2,3,7,8-TCDF Concentrations in lake  trout from Lakes  Superior, Michigan,
Huron and Ontario, and in walleye from Lake Erie, pg/g.

                                            .LAKE
 Year          Superior       Michigan      Huron         Erie           Ontario

 1978(1)        32.7           27            31.5           24.5           54.8
 1984(2)        14.8           39.5           22.8           11.3           18.5
 1988(1)        7.2            13.4           11.2           7.8            8.9
 1990(3)       20.7           Na            Na            Na            72.1
 1992(4)       24.1           16.1           11.5           15.5       .    40.25
                                                                                    18

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Na Not analyzed.

(1) Great Lakes National Program Office, unpublished data
(2) De Vault etal.( 1989)
(3) Whittle etal. (1992)
(4) Fisheries and Oceans Canada, unpublished data.
Trends in 2,3,7,8 TCDD in whole lake trout have been monitored in the waters of Lake Ontario
since 1977 by Fisheries and Oceans Canada. Results from this program indicate that there has
been little, if any change in mean 2,3,7,8 TCDD concentrations over the period 1977 through
1992 (Table 12)               -
Table 12.  2,3,7,8 TCDD concentrations in whole lake trout from Lake Ontario.

  Year                  TCDP(pg/g)      Standard Error    Number of Samples

  1977                  13.0              3.0               2
  1978                  32.5              1.5               2
  1979                  39.6              6.8               9
  1980                  34.4              6.7               10
  1981                  29.4              2.7               16
  1982                  40.8              10.6              9
  1983                  3.1.6              5.0               14
  1984                  11.4              2.0               17
  1985                  34.1              1.7               25
  1986                  42.7              6.9               10
  1987                  37.4              2.75              7
  1988                  53.1              3.88              17
  1989                  34.0              3.32              16
  1990                  44.3              3.14              18
  1991                  40.3              4.94              13
  1992                  49.9              5.72              12

Fisheries and Oceans Canada.

For more information on 2,3.7.8-TCDD trends in Lake Ontario see section 4.3 Concentrations
and Trends in Herring Gulls
Toxic Contaminants - SOLEC Background Paper                                         19

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HCB

Hexachlorobenzene has been monitored in coho salmon fillets and in whole lake trout from the
Great Lakes for several years. These data indicate that concentrations are below detection limits
of 0.005 ug/g in coho salmon fillets and 0.01 ug/g in lake trout.

B(a)PandPb.

Because  B(a)P  is metabolized by  fish and other  vertebrates, and  Pb  is not significantly
bioaccumulated, these compounds are not routinely monitored in fish tissue. Special studies for
both compounds indicate very low concentrations in most Great Lakes fish.

Mirex

Mirex was reported in water samples from Lake Ontario during the mid-1980's at concentrations
on the order of 10-50 pg/1 (Sergeant et al., 1993).  Although historical discharges to the Niagara
and  Oswego Rivers are known sources, mirex  was used elsewhere in the basin and other
potential  source  areas are believed to exist.   In  1988, mirex concentrations in lake trout from
Lake Ontario Ranged from 0.6 to 0.9 ug/g (Sergeant et al., 1993).  Lake trout from Lakes Erie
and  Huron also  contained detectable quantities of mirex^ but at concentrations 100-200 times
lower than in trout from Lake Ontario (Sergeant et al., 1993).  Fish tissue residues of mirex in
Lake Ontario fish have declined significantly since the early 1980s.
FORAGE FISH

Rainbow smelt from Lakes Superior, Huron, Erie and Ontario have been routinely monitored by
Fisheries and Oceans Canada since 1977. These data provide a view of contaminant trends one
trophic level below the lake trout, walleye and coho salmon discussed above. Over the period of
this program,  concentrations of PCB, total DDT, and Hg have declined significantly in smelt
from Lakes Superior, Huron, Erie and Ontario (Figures 11,12,13).  Samples from Lake Ontario
consistently have the highest concentrations of PCBs and total DDT, while those from Lake
Superior have the highest Hg concentrations.

In addition  to using top predator fish species and their forage fish species  to  assess toxic
contamination in the Great Lakes, contaminant concentrations in young  of the year spottail
shiners are also monitored by the Ontario Ministry of Environment and Energy (OMEE). These
fish do not travel extensively during their  first year of life, so they provide a measure of
contaminant exposure in local, near-shore areas. At most collection sites, PCBs and total DDT
concentrations declined significantly from the mid-1970's to 1990 (Suns et al., 1993).  Even so,
concentrations of PCBs in spottail shiners in 1991/1992 exceeded the Great Lakes Water Quality
objective of 100 ng/g at most of the sites studied in the Niagara River and Lake  Ontario (Figure
14).
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4.3   Concentrations and Trends in Herring Gulls

In the early 1970s, fish-eating birds (gulls, terns, cormorants, herons, etc.) on the Great Lakes
suffered widespread reproductive failure, declining population levels and eggs with very thin
shells. These phenomena were largely attributed to high concentrations of toxic contaminants in
their diet.  The Canadian Wildlife Service has been monitoring contaminants in herring gull eggs
and in the adults since 1974. This monitoring program provides important data on a terrestrial
species which is closely tied to the aquatic food web. Data for several, representative colonies
are discussed below. These data are a subset of a much larger data base.

Between 1974 and 1993,  the concentrations of PCBs and DDT/DDE declined significantly at
most  sites (Figures 15 and 16).  In eastern Lake Ontario (Figure 17), 2,3,7,8 TCDD declined
significantly from the high concentrations observed in 1971 and 1972.  As was observed for fish
tissue concentrations, most of the decrease in these compounds occurred between 1974 and the
mid  1980s.  Since then the rate of decrease of these contaminants in gull eggs has been  much
slower.
Contaminant concentrations in herring gull eggs from around the Great Lakes in 1992 tended to
follow a geographical distribution similar to that of top predator fish. PCB concentrations in the
eggs  were generally higher in  Lakes Erie  and Ontario, although one site in Lake  Huron
contained the greatest concentrations (Figure  18).  Concentrations of 2,3,7,8:TCDD (Figure 19)
and mirex (Figure 20) were the highest in Lake Ontario eggs.
4.4  Atmospheric Concentrations

We have limited data and understanding of atmospheric concentrations and processes.  However,
a series of workshops involving researchers from across the US. and Canada has resulted in
consensus atmospheric concentrations for several contaminants in the early  1990s (Table 13).
Work is underway to improve our knowledge in this area. The US. and Canada are cooperating
on the International Atmospheric Deposition Network  (IADN) which is designed to measure
atmospheric deposition of a long list of organic and metal contaminants. In addition, research
studies  conducted  by government and  university  laboratories are  rapidly  advancing  our
understanding in this important component of the contaminant picture. Studies are underway to
improve our understanding of the geographical distribution of contaminants, as well as processes
such as volatilization and large particle transport.
Toxic Contaminants - SOLEC Background Paper                                        21

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Table  13.  Consensus atmospheric concentrations of toxic organic contaminants in the
Great Lakes region during the early 1990's (ng/m3 for air and ng/I for rain).
  Contaminant               Air                              Rain
                            Concentration
                Summer     Fall/Spring       Winter
PCBs
HCB
Dieldrin
DDT
Toxaphene
B[a]P
0.4 0.2
0.15
0.08
0.05-0.1
0.06
0.005
0.1
0.1
0.02
0.02
0.01

2.0
0.06
0.4


2.0
From Eisenreich and Straehan (1992).
Recent studies of PCB concentrations over the Great Lakes in 1991-1992 (Figure 21) suggest
that, with the exception of urban areas such as Chicago and Detroit/Windsor, concentrations are
relatively uniform across the Basin.  Most notable in Figure 21 is the nearly ten-fold increase in
atmospheric  PCB concentrations that  occurs as one moves from north to south down Lake
Michigan toward the Chicago-Milwaukee area.
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5.0   Linkages With Other Ecosystem Components
Toxic contamination is but one of several stressors impacting the Great Lakes ecosystem.  As all
elements of the Great Lakes ecosystem are ultimately linked, so are contaminants linked to other
factors. The links between contaminants and aquatic community health, human health, nutrients,
the economy, and habitat (including wetlands) are very briefly explored below.

Aquatic Community Health

Toxic contaminants can result in unhealthy aquatic communities by causing disease, deformities,
abnormal behavior, and reproductive failure, all of which can impair the fitness of a population.
As more becomes known about the  interactive  effects of toxic contaminants,  the potential
adverse effects of these chemicals on both fish and fish-eating birds  becomes more evident.  In
spite of major  reductions in the environmental  concentrations of most toxic contaminants,
deformities  and reproductive impairments are still observed in fish-eating birds  certain areas
(Giesy et al.  1994).

Human Health

The  human population of the Great Lakes Basin is exposed to contaminants through water, air,
and  food.  Because of the very low concentrations in water and air, fish consumption is the
major route  of  human exposure to contaminants.  To reduce this exposure, the  Great  Lakes
States and the Province of Ontario issue Sport Fish Consumption Advisories, at least, annually.
While the contaminant concentrations which trigger advisories vary between jurisdictions, they
all advise reduced consumption of those species and sizes of fish with the highest contaminant
concentrations.

Traditional health analyses have focused on risks of contracting cancer.  However, reproductive
toxicity and outcomes have been studied recently because they may be more sensitive indicators
of chemical impacts. Studies conducted in the late 1970s and early 1980s documented effects
such as reduced  head circumference and subtle behavioral deficits among infants of mothers who
consumed large quantities of Great Lakes fish.  Recent studies conducted in the area of  Green
Bay, Lake Michigan, found  no adverse effects  among offspring bom to fish consumers. The
Green Bay results appear to be due to decreases in fish tissue concentrations and the fact that the
public appears to be following fish consumption advisories, both of which result in decreased
exposure.
Nutrients

Toxic contaminants accumulate in or adsorb onto phytoplankton as part of the bioaccumulation
process.  The abundance and species composition of phytoplankton  populations are highly

Toxic Contaminants - SOLEC Background Paper                                        23

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dependent on the nutrient concentrations and on the ratio of nitrogen, phosphorus, and silica.
The reduction in the amount of phytoplankton and the restoration of algal species compositions
more typical of oligotrophic  communities are desired results of nutrient control  programs
However, they may have the undesirable effect of increasing concentrations of hydrophobic
contaminants in fish.  This ironic phenomenon may come about in two ways.  First,  the larger
phytoplankton  populations associated  with  more  eutrophic systems provide -a more direct
pathway for plankton-bound contaminants to reach the sediments, thereby removing them from
the water column.  Secondly,  the energy transfer up the food chain is more efficient in more
oligotrophic  systems.  This  low nutrient-high contaminant situation has  been observed in
Scandinavian lakes (Larsson et al., 1992) and higher bioaccumulation factors were observed in
the  oligotrophic/mesotrophic   northern  Green Bay,   Lake  Michigan   compared  to  the
hypereutrophic southern Green Bay in 1989 (David De Vault, USEPA, personal communication
1994). While an increase in contaminants in  fish could  result from successful nutrient control,
this would be short lived as contaminant loadings continue to decline.
Economy

The presence of contaminants in the Great Lakes ecosystem has both direct and indirect costs.
These include in reduced revenue  from sport and commercial fisheries,  increased costs for
treating drinking water and disposal of dredge spoils. Indirect costs can include increased costs
for health care and loss of tourist revenue due to concern over contaminant exposure.

Because environmental  contaminants are the result of industrial and agricultural activity, the
discharge of many contaminants  are directly tied to economic cycles. Discharges of currently
used chemicals will typically decline if the industries using those chemicals are in a recession
period, and the discharges will increase during periods of economic growth
Habitat and Wetlands

Toxic contaminants can exert deleterious effects on all biotic components of the Great Lakes
ecosystem, not just fish, birds and humans.  The productivity of aquatic plants, invertebrates,
amphibians, reptiles and mammals  can also be significantly reduced upon exposure to toxic
substances .  Contaminants can exert their effects both  directly and indirectly on the aquatic
community. For example, contaminated sediments can directly inhibit successful spawning of
some fish species as well as severely limit the survival of a benthic community.
                                                                                     24

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6.0   Key Issues to Consider


Continuing Problems and Concerns

Concentrations of  most toxic contaminants in the  Great  Lakes ecosystem have decreased
substantially since  the  1970s, However, contaminants  are still present throughout the Great
Lakes, often at levels above standards or guidelines. Issues to consider:

      - Fish consumption restrictions continue in all of the Great Lakes.

      - Hot spots of contaminated sediments remain.

      - Elevated levels of contaminants continue in fish  and wildlife.

      - Deformities  in wildlife  continue to occur in localized areas  such as Green Bay and
      Saginaw Bay.

      - Levels of contaminants appear to be leveling  off in some fish and avian species. While
      these findings may be the result of changes in food webs, they bear further attention.

      - The source and chemistry of some contaminants, such as toxaphene, are not sufficiently
      understood to reduce or eliminate sources.
Toxic Contaminants  SOLEC Background Paper                                       25

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 7.0   References
 Czuczwa, J.M. and R.A. Kites. 1984. Environment?} fa{e of combustion generated polychlorinated dioxins and fiirans.
 Environ. Sci. Technol. 18:440-450. (p!5)                                         ,

 Czuczwa, J.M. and R.A. Kites. 1986. Airborne dioxins and dibenzofurans:  sources and fates. Environ. Sci. Technol.
 20:195-200.

 De Vault, D.S., Anderson, D., and P. Cook. 1992. PCBs in the Green Bay water column 1989-90. International
 Association for Great Lakes Research. Abstract.

 De Vault, D.S., Dunn, W., Bergqvist, P.A., Wiberg, K, and C. Rappe, 1989. Polychlorinated'dibenzofurans and
 polychlorinated  dibenzo-p-dioxins in Great Lakes fish: a baseline and inter-lake comparison. Environ. Toxicol. and
 Chemistry 8:1013-1022.

 De Vault, D.S.  and H. J. Harris. 1989. Green Bay/go^ River mass balance study plan. USEPA, Great Lakes National
 Program Office, Chicago, IL. EPA 905/8-89-002.

 .Eisenreich, S.J. and W.M.J. Strachan. 1992.  Estimating Atmospheric Deposition of Toxic Contaminants to the Great
 Lakes: an Update. Workshop held at Canadian Centre for Inland Waters, Burlington, Ontario, Jan. 31- Feb. 2,1992

 Giesy, J. P., Ludwig, J. P., and D. E. Tillitt. 1994. Deformities in birds of the Great Lakes region. Environ. Sei Technol.
 28:128-135

 Government of Canada.  1993. Canadian  Environmental  Protection  Act.  Polychlorinated  dibenzodioxins  and
 polychiorinated dibenzofurans. Priority Substances List, Assessment Report No.l.

 Governments of US and Canada. 1987. Great Lakes Water Quality Agreement of 1978. as amended by Protocol signed
 November 18.1987.

 International Joint Commission. 1985. Report on Great Lakes Water Quality. A Report to the DC by the Great Lakes
 Water Quality Board. Presented at Kingston, Ontario. 212pp.

 International Joint Commission. 1991. Cleaning up the Great Lakes: A Report from the Water Quality Board to the UC
 on Toxic Substances in the Great Lakes Basin. 46pp.

 International Joint Commission. 1993a. A Strategy for Virtual Elimination of Persistent Toxic Substances. Volume 1.
 Report of the Virtual Elimination Task Force. Windsor, Ontario. 72pp.

International Joint Commission. 1993b. A Strategy for Virtual Elimination of Persistent Toxic Substances. Volume 2:
appencx. Seven Report of the Virtual Elimination Task Force.

Jeremiason, J.D., Hornbuckle, K. C., and S. J. Eisenreich. 1994. PCBs in Lake Superior. 1978-1992: Decreases in water
concentrations reflect loss by volatilization. Environ. Sci. Technol. 28:903-914.

Larsson, P., Collvin, L., Okla, L., G. Meyer. 1992. Lake productivity and water chemistry as governors of the uptake of
persistent pollutants in fish. Environ. Sci. Technol. 26:346-352.

Lefkovitz, L. F. 1987. The particle mediated fractionation of PCBs in Lake Michigan. Masters thesis, University of
Wisconsin, Madison, WI. 58 pp.


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L' Italien,  S.  1993.  Organic  Contaminants  in the Great Lakes1986-1990.  Report No: EQB/IWD-OR/93-02-L
Environment Canada, Environmental Quality Branch, Ontario Region, Burlington, Ontario.

Mackay, D., M. Diamond, F. Gobas and D. Dolan. 1992a. Virtual Elimination of Toxic and Persistent Chemicals from
the Great Lakes: The Role of Mass Balance Models. A Report to the Virtual Elimination Task Force, International Joint
Commission, Windsor, Ontario. 63pp.

Mackay, D.,  S. Sang, M. Diamond, P. Vlahos,  E.  Voldner and D. Dolan, 1992b. Mass Balancing  and Virtual
Elimination. A Peer Review Workshop at the University of Toronto, Ontario, December, 7-8,46pp.

NATO (North Atlantic Treaty Organization).  1988. International Toxicity Equivalency Factor fl-TEF) method of risk
assessment for complex mixtures of dioxins and related compounds. Pilot study on international information exchange
on dioxins and related  compounds. Committee on the Challenges of Modem Society. No. 186.

Pearson, R. F. and D, L. Swackhamer. 1994. PCBs in Lake Michigan water: Comparison to 1980 and a mass budget for
1991. Submitted to Environ. Sci Technol.                              \

Sergeant, D.B., M.Munawar, P.V.Hodson, D.T.Bennie and S.Y, Huestis. 1993. Mirex in the North American Great
Lakes: New detections and their confirmation. J. Great Lakes Res. 19(1): 145-157.

Sitarz, W., D.T. Long, AHeft, S.J. Eisenreich,  and DJL Swackhamer. 1993. Accumulation and Preliminary Inventory of
Selected Trace Metals in Great Lakes Sediments. Sixteenth Midwest Environmental Chemistry Workshop Sediments.
October 17-18,1993.

Stevens, R.J.J. and M.A. Neilson. 1989.  Inter- and intra-lake distributions of trace organic contaminants in surface
waters of the Great Lakes. J. Great Lakes Res. 15(3): 377-393.

Suns, JC, G.C. Hitchin and D. Toner.  1993. Spatial and temporal  trends in organochlorine contaminants in Spottail
Shiners from selected sites in the Great Lakes. J. Great Lakes Res. 19(4): 703-714

Strachan, W.MJ.  and S.J. Eisenreich.  1988.  Mass Balancing of Toxic Chemicals in the Great Lakes: The Role of
Atmospheric Deposition. International Joint Commission, Windsor, Ontario. 113pp.

Swackhamer, D.L. and D.A. Armstrong. 1987. Distribution and Characterization of PCBs in Lake Michigan Water. J
Great Lakes Res. 13:24-36.

U.S. Environmental Protection Agency. 1980. Ambient Water Quality Criteria for Toxaphene. Report No. EPA-440/5-
80-076. 76pp.

Weseloh, C. 1993. Toxic Contaminants  in Great Lakes Herring Gulls 1974-1992. Canadian Wildlife Service.

Whittle, D.M., D.B. Sergeant, S.Y. Huestis  and W.H. Hyatt. 1992.  Foodchain accumulation of  PCDD and PCDF
isomers in the Great Lakes aquatic community. Chemospherc. 25:181.

Wong, P.T.S., Y.K. Chau, J. Yaromich, P. Hodson and M. Whittle.  1989. Applied Organometallic Chemistry. Volume
3,59-70.
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APPENDIX A:   Existing Monitoring Programs


CONTAMINANT MONITORING PROGRAMS

Contaminant Loadings

Since 1987, the United States has tracked the emissions of certain pollutants through the Toxics
Release Inventory, and Canada has recently started a similar program, the National Pollutants
Release Inventory. These programs require dischargers to report the release to the environment
of certain chemicals above threshold amounts.

In 1989 the U.S. conducted a pilot load monitoring program on Green Bay, Lake Michigan, as
part of the Green Bay Mass Balance Study.  Building on the Green Bay study, the USEPA, in
cooperation with other federal and Great Lakes State agencies, has implemented an enhanced
monitoring program to estimate atmospheric and tributary loadings of a wide range of toxic
substances to Lake Michigan, The U.S. enhanced tributary monitoring programs are linked to
monitoring in other media to provide data for the calibration of mathematical models.  These
models  are intended to provide environmental managers with the ability to evaluate effects of
potential regulatory and remedial actions.

On  the  Canadian side, there are  various programs run by both  the Federal and Provincial
government agencies.  Some of these programs include the binational Niagara River Toxics
Management Plan and St. Clair River Management Plan, St. Lawrence River Vision 2000, Great
Lakes 2000 and the OMEE Tributary Monitoring Program.

Substantial research is also being conducted  under the sponsorship of USEPA, Environment
Canada and the OMEE to understand the processes of volatilization  and short range atmospheric
transport.

Water

Large volume surface water samples were  collected each spring  between  1986 and 1990
throughout  the Great Lakes by the Ontario  Region  of Environment Canada, Inland Waters
Directorate.   Because of the need to provide  information for mass balance models, a new
approach was  initiated on Lake Ontario in  1992 and 1993.   This involves  processing large
volumes of water at six stations each spring, summer and fall.

In 1993 USEPA established an annual program to assess organic contaminants at a limited
number (5 to 6) of sites on each of the Great Lakes in the early spring. These data will assist the
interpretation of data on contaminants in fish tissue, support mass balance modeling efforts, and
over time, allow assessment of trends in the concentrations of contaminants in the open waters.
Toxic Contaminants - SOLEC Background Paper                                       29

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In 1994, USEPA  and partner agencies began an intense study of contaminants in all media
(water,  air,  sediments, biota) in Lake Michigan  to  develop  and calibrate a  predictive
mathematical model.

Sediments

In 1990,  the Ontario Ministry  of Environment  and Energy  (OMEE)  began a program to
periodically monitor sediment quality, among other environmental quality features, at a network
of inshore  stations for the purpose of  identifying  changes over time, detecting emerging
problems and providing reference information. Trace metals and organic contaminants are also
measured annually in  suspended solids and benthic samples from 17 large Ontario tributaries to
the Great Lakes.

USEPA periodically sponsors studies of sediments in the depositional areas of the Great Lakes
to determine the historical loading profiles and to develop a better understanding of the source of
chemicals to the  lakes, as well  as the impact of contaminated sediments on water column
concentrations.

Fish

US. EPA, Great Lakes National Program Office in cooperation with the US. National Biological
Service and Great Lakes  States  annually collects and analyzes whole lake trout from Lakes
Superior,  Huron, Michigan and Ontario and walleye  from Lake Erie for pesticides, PCBs and
other industrial  contaminants. This program began in 1970 on Lake Michigan and in 1977 on the
other lakes. The Canadian Department of Fisheries and Oceans annually collects and analyzes
whole lake trout and smelt from multiple sites on Lakes Superior, Huron, Erie and Ontario for
PCBs, pesticides and metals. This program began in 1977. Both programs maintain fish tissue
archives which  are used to provide retrospective analyses. These archives have provided data on
historical  levels of contaminants such as dioxin,  furans and  planar PCBs.  The  open lake
sampling programs provide data  to assess long term trends in contaminant concentrations, the
relative severity of contamination between lakes, the impacts of near-shore controls on the  open
lake, and of non-point  source contributions to the toxic contamination of the lakes.

The  U.S.  Environmental  Protection  Agency,  in cooperation with the U.S. Food and Drug
Administration  and the Great Lakes States, also annually collects and analyzes fillets of coho or
chinook salmon from  each of  the lakes.  These data are useful not only to monitor trends in
organic contaminants in  fish, but they also provide a  measure of potential  exposure  to
contaminants by fish-eating human populations.

The  Ontario Ministry of  Environment and Energy  and the Ministry  of Natural  Resources
cooperate to monitor contaminants in lean, dorsal, skinless, boneless muscle tissue from Great
Lakes fish to provide consumption advice to sport anglers. The Great Lakes States also monitor
contaminant residues  in fillets of several sport fish species to provide consumption advice to
sport anglers.

                                                                                     30

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Contaminant residues in spottail shiners have been monitored by the Ministry of Environment
and Energy since 1975 to assess the effectiveness of remediation and to monitor trends.  Over a
17 year period, shiners have been collected and tested at more than 150 sites on the Great Lakes
and  their connecting channels.  Forage fish such as shiners  provide a link in  contaminant
transfers to  higher  trophic  levels such  as  fish-eating  wildlife birds and predatory  fish.
Comparable  monitoring has  been  conducted by New York for their jurisdictional waters in
Lakes Erie and Ontario, the Niagara and St. Lawrence Rivers. Following initial studies in 1984-
1987, analysis of spottail shiners is being conducted every five years  as an indicator of trends
and remedial success.

Birds                                       .

The Canadian Wildlife Service of Environment Canada annually collects and analyzes eggs from
up to 15 herring gull colonies around the Great Lakes.  Biological parameters such as eggshell
thickness, reproductive success, behavior, physiological markers and population size have also
been measured. This program has been ongoing since the early 1970s.
Mathematical Models

Screening-level models have been developed for PCB and Hg in Lakes Ontario and Superior.
USEPA recently built a state of the art model for Green Bay, Lake Michigan  (De Vault and
Harris,  1989), and is currently working to adapt this to the main body of Lake  Michigan. The
Green Bay model predicts the behavior of individual PCB congeners from loadings through top
predator fish.  The model incorporates the ability to predict concentrations which will likely
occur as a result of changes in toxic  substance loadings, and can incorporate the linkages to
changes in  other environmental  components  such  as changes such  as nutrient and  solids
loadings.
Toxic Contaminants - SOLEC Background Paper                                         31

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APPENDIX B:  Descriptions of Contaminants
Aldrin and Dieldrin

These chemicals were used primarily as insecticides. Most uses have been banned, although
dieldrin is still used in limited amounts for termite control in the Great Lakes basin (DC, 1991).
Aldrin naturally degrades to dieldrin in the environment, while dieldrin is persistent.  The uses
of both pesticides have been eliminated or severely restricted.

DDT and its breakdown products, including p.p -DDE
DDT is an insecticide which was introduced to North America in 1946.  Its use was restricted
beginning in 1968 and is now banned. DDT and its breakdown products, including p,p DDE,
are still found in the Great Lakes.  They probably originate from a number of sources including
lake bottom sediments, contaminated tributary sediments, runoff from sites of historical use,
leaking landfill sites, illegal use of old stocks,  and long range  transportation  through the
atmosphere from countries still using DDT.

DDT can disrupt the  hormone and enzyme systems.  It gained notoriety in the late 1970s for
causing eggshell thinning in birds, and it is associated  with embryo mortality and sterility in
wildlife.   Recent research in the  Great Lakes indicates that p,p'-DDE and o,p DDT possess
estrogenic activities, and they have the potential to feminize wildlife embryos, i.e., to alter the
hormonal balance and reproductive structures.

Dioxins

Dioxins,  which comprise a family of 75 related chemicals, are the unwanted byproducts of
combustion and some  industrial processes that use chlorine. The most significant dioxin sources
are the wood preservative, pentachlorophenol, municipal incinerators, and pulp and paper mills
using chlorine  for the bleaching process (Canada 1993). One member of this family, 2,3,7,8-
tetrachloro-di-benzo-dioxin (TCDD), is considered to be the most toxic synthetic chemical (IJC,
1991).  TCDD can act as an endocrine disrupter, and may  suppress various immune systems
components.  Recent  process changes in the pulp and paper industry have greatly reduced this
source of dioxins.

Furans

This family of 135  related  chemicals are unwanted  byproducts  of combustion, industrial
processes that use chlorine, the manufacture of pentachlorophenol and as contaminants in PCBs.
One member, 2,3,7,8 TCDF, is similar to 2,3,7,8 TCDD but is considered to be about one tenth
as toxic (NATO, 1988). Furans can also act as endocrine disrupters (IJC, 1993).
Toxic Contaminants  SOLEC Background Paper                                       33

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Hexachlorobenzene

Hexachlorobenzene (HCB) is a member of the chlorobenzene family.   Chlorobenzenes are
widely used and are found in industrial wastes, atmospheric discharges and municipal waste
water.

Hexachlorobenzene was used as a fungicide on cereal crops in Canada between 1948 and 1972.
It is  also  created during the manufacture of other pesticides,  and is  still used  in  limited
applications. HCB is persistent in the environment and can interfere with enzymes that control
the production of hemoglobin, a component of blood, and can be an endocrine disrupter. HCB
can also affect the nervous system, liver, reproductive system and produce cancer in laboratory
animals.

Lead

Lead is an  industrial metal which has been used in a variety of purposes including gasoline,
plumbing,  leaded glass, paints, and batteries.  Lead is released as a result of coal and oil
combustion,  metal  mining,  smelting and manufacturing,  cement  manufacturing, fertilizer
production and waste incineration (DC, 1993b).

Lead can exist in inorganic and organic forms such as triethylead and tetraethyl lead. Tetraethyl
lead or (organoleads) are volatile, easily partitioned into lipids, adsorbed into particulates and
volatilized to the atmosphere (Wong et al., 1989).
                                                              i
Lead is a neurotoxin which causes nervous system damage. It is also immunotbxic and can
depress the antibody response  in mammals.

Mirex

Mirex (Dechlorane) was used as an insecticide and fire retardant. Mirex is extremely persistent,
and has been shown to cause reproductive problems and cancer in laboratory animals (IJC,
1991).

Mercury

Mercury is  an industrial metal with a large number of uses ranging  from slime prevention to
electrical components.  It is still used in paints, switches, thermostats, batteries and some lights.
World mine production of mercury in 1989 ranged from 5,800 to 7,000 tones, and estimates of
global annual emissions from anthropogenic sources vary between 11,000 and 20,000 tones (IJC,
1993b).  Much of the mercury entering the Great Lakes results from the combustion of fossil
fuels, particularly coal, which releases mercury as a vapor.  Mercury is also released from
natural sources such as emissions from vegetation,  forest fires, soils and water (IJC, 1993b).
Mercury  exists  in  many different  forms (elemental,  inorganic ion,  and organic) which
interconvert, each with different properties and toxicities. Mercury accumulates rapidly in fish,

                                                                                     34

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 and can accumulate in the human brain, kidney and liver, and cause nervous system disorders
 (IJC, 1991).

 Polychlorinated Biphenyls (PCBs)

 Polychlorinated biphenyls are a family of 209 related chemicals, many of which have toxic
 properties.  Some members of this family are of particular concern because they have chemical
 structures and biochemical characteristics  similar to dioxins,  PCBs have been used since the
 1930s in electrical and hydraulic equipment, which accounts for about 60% of the total usage.
 They were also used in various plasticizers (25% of total use), hydraulic fluids and lubricants
 (10%) and in consumer products such as carbonless copy paper, inks, adhesives, flame retardants
 and fluorescent lights (5%). After 1971, PCB use was restricted to closed electrical systems. In
 1975, the manufacture and importation of PCBs was prohibited in the United States.

 Although the manufacture of PCBs stopped in the late 1970s, 65% of the world's 1,200,000 tons
 of PCBs are still in use in electrical products, or deposited in landfill sites. As of 1982, only 3%
 of PCBs in the US had been destroyed, with 140,000  tons in landfills and  70,000 tons in the
 environment (IJC, 1993b). In  1988, over 280,000 tons of PCBs were still in use in the US (IJC,
 1993b) and over  16,000 tons of PCBs were in use in Canada, where another 12,000 tons were in
 storage (IJC, 1993b).

 PCBs are among the most ubiquitous chemicals in the Great Lakes ecosystem.  They are very
 persistent, accumulate rapidly in the food chain, and have been linked to health problems such as
 embryo mortality and wildlife deformities.  PCBs possess estrogenic activities, and can act as
 hormone mimics.

 Polynuclear Aromatic Hydrocarbons (PAHs)

 Benzo(a)pyrene ( BaP), is a PAH which has been linked to cancer in wildlife and humans.  BaP
 is produced during combustion of fossil fuels and wood, and during incineration.

 Toxaphene

Toxaphene  is a poorly characterized mixture of several  hundred individual  chemicals.
Toxaphene  was the most common substitute  for DDT after its ban in 1971  and was used
extensively in the southern United States on cotton crops.  Its use has been restricted in the US
since 1982. Toxaphene was  removed  from general use in  Canada in  1974,  although small
amounts  are still  allowed  for use in  Canada (Government of Ontario,  1993; IJC,  1991).
Toxaphene is  acutely toxic to fish,  but relatively  non toxic to mammalian species.  It has,
however, been identified as an animal carcinogen, (US EPA, 1980).

Analytical methods for toxaphene are imprecise and most data is for "Toxaphene like" mixtures.
recent evidence suggests that there may be sources other than the pesticide for many components
of this mixture.

 Toxic Contaminants - SOLEC Background Paper                                        35

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LIST OF FIGURES


 1.    Sediment Cores showing PCB and DDT profiles

 2.    Anthropogenic Pb and Hg Sediment Profiles in Dated Sediment Cores from the Great
      Lakes

 3.    Accumulation Rates of Toxaphene in Lake Michigan, Lake Superior and the Apostle
      Islands                                                                '

 4.    Toxaphene mass in sediments from in Lake Michigan, Lake Superior and the Apostle
      Islands, adjusted for sediment-focusing.

 5.    PCBs in lake trout, all lakes, combined US and Canadian data. Walleye for Lake Erie
      instead of lake trout.

 6.    PCBs in coho salmon, all lakes, US data

 7.    DDT in lake trout, all lakes, combined US and Canadian data. Walleye for Lake Erie
      instead of lake trout.

 8.    DDT in coho salmon, all lakes, US data

 9.    Dieldrin in lake trout, all lakes, US data. Walleye in Lake Erie instead of lake trout.

10.    Toxaphene in lake trout, all lakes US data.

11.    PCB trends in smelt. Canadian data

12.    DDT trends in smelt. Canadian data

13.    Mercury trends in smelt. Canadian data

14.    PCBs in spottail shiners, 1990-1991.

15.    PCB trends in herring gull eggs

16.    DDE trends in herring gull eggs

17.    Dioxin trends in herring gull eggs

18.    PCB, dieldrin, DDE, HCB geographic distribution in herring gull eggs

  *
Toxic Contaminants - SOLEC Background Paper                                      37

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19.    Dioxin geographic distribution in herring gull eggs




20.    Mirex, oxychlordane and heptachlor-epoxide geographic distribution in herring gull eggs




21.    PCB concentrations in air over the Great Lakes,
                                                                                     38

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      PCBS AND DDT IN LAKE MICHIGAN AND LAKE ONTARIO SEDIMENTS
                   Lake Michigan
                          Lake Ontario
                   PCB
DDT
                                                       PCB
                                    DDT
      at
                   SO  1OO 15O  2OO 25O
                                           ui
                2OOO
                199O
                198O
                197O
                1960
                1950
                1940
                193O
                1920
                191O
                19OO
                                                      1OO 2OO 3OO 4OO 5OO 6OO
                                                            (ng/g)
Figure 1.     Concentrations of PCis and DDT in sediment cores from Lake Michigan and Lake Ontario, dry mass (data from
          S. Eisenreich, University of Minnesota).

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LEAD AND MERCURY IN GREAT LAKE BOTTOM SEDIMENTS
 Lake  Superior
   2000
   1980
   1960
   1940
   1920
|  1900
> '
   1880
   1860
   1840
   1820
   1800
0  50 100 150200250300
Pb (ug/g) and Hg (ng/g)
                                  Lake Michigan
                                  --Pb    -*-Hg
                                  Lake Ontario
   2000
   1980
   1960
   1940
   1920
C
U  1900
>
   1880
   1860
   1840
   1820
   1800
                                 0  50 100 150200250300
                                 Pb (ug/g) and Hg (ng/g)
                                                Ul
                                                           Pb
                                              Hg
                                 0  50  100 150200250300
                                 Pb (ug/g) and Hg (ng/g)
Figure 2.    Anthropogenic lead (Pb) and mercury (Hg) in dated sediment cores from Lakes Superior, Michigan, and Ontario
         (data from D. Long, Michigan State University).

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                    ACCUMULATION RATES OF TOXAPHENE
                               IN THE GREAT LAKES
            YEAR
                       2000
                       1975
                       1950
1925
                       1900
                        1875
                        1800
                           0.00   0.20    0.40    .060    0.80   1.00
                                Accumulation Rate (ng/cm 2/yr)
Figure 3.    Rates of accumulation of toxaphene in sediments from Lakes Michigan and Superior, and from the Apostle Islands
         (data from D. Swackhamer, University of Minnesota),

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                  TOXAPHENE INVENTORY
LAKES MICHIGAN AND SUPERIOR, AND THE APOSTLE ISLANDS
   ng/cm2
            20
            15
            10
                    L. Michigan
L. Superior    Apostle Islands
    Figure 4.    Toxaphene mass In sediments from Lakes Michigan and Superior, and the Apostle Islands Outer Island, adjusted for
            sediment distribution (focusing) (data from D. Swackhamer, University of Minnesota),

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                                           PCB Levels  in  Lake  Trout
                                                                                           IBB Wt W4t BIB MB 1H2 HM19H I98B 19 1HZ.
                                                                                                  Canada  **
                                                                                                 Ute Ontario
                                                                                                  Canada

                                                                                                  United States
Figure 5.    PCB levels (pg/g wet weight) in whole lake trout

Data Source: * US Environmental Protection Agency, Great Lakes National Program Office - 10 fish composite samples, 600-700 mm. T.L.. (x  98% C.I.)
           (Lake Erie data are for wallye)                            _
         " Canacflan Department of Fisheries and Oceans -  individual fish age 4+ yrs.,? S.E.

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              0.0
                      Laki
                                            PCB in Coho Salmon
Figure 6. PCB levels (|ig/g wet weight x S.E.) in coho salmon skin-on filet



Data Source: US Environmental Protection Agency, Great Lakes National Program Office

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                                          Total  DDT  Levels  in  Lake Trout
tm m n m wi IM m H iw *
     United States *
     Late Superior
              m iro MM mi im IM UK i
                    United States
                    Lake Michigan
                                                                                              Canada

                                                                                              United States
      DDT levels (fig/g wet weight) in whole lake trout

      US Environmental Protection Agency, Great Lakes National Program Office - 10 fish composite samples, 600-700 mm. T.L. (x~ 95% C.I.)
      (Lake Erie data are for wallye)                            _
     ' Canadian Department of Fisheries and Oceans - individual fish age 4+yrs., x  S.E.
Figure 7.

Data Source:

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                                  Total DDT in Coho Salmon
Figure 8. Total DDT levels ftig/g wet weight x S.E.) in coho salmon skin-on filet
Date Source: US Environmtntal Protection Agency, Great lakes National Program Office

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                                               Dieldrin in  Lake Trout
                                                                1978 1880 1962 1984 1968 1988 1980

                                                              Lake Erie
Figure 9.   Dieldrin levels (|xg/g wet weight) in whole lake trout

Data Source:  US Environmental Protection Agency, Great Lakes National Program Office - 10 fish composite samples, 600-"700 mm T.L.. (x" 95% C.I.)
            (Lake Erie data are for wallye)

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            2.0
Toxaphene  in Lake  Trout
               oo
                                                            ** *
                      Lake Michigan
       19*0 198! 1984 19M 1988 1990

    Lake Erie
                                                                                   ** *
                                                                                 1984 1886 IBM 1990

                                                                              ntario
Figure 10. Toxaphene levels (ng/g wet weight x  95% C.I.) in 10 fish composite samples, 600 - 700 mm T.L
Data Source: US Environmental Protection Agency, Great Lakes National Program Office

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                  2.5
                                           PCB Trends  in Smelt
Figure 11.  PCB levels (pg/gS.E.) in rainbow smelt whole fish (wet weight) in the Great Lakes, 1977-1992.
  * >50% results below detection In* (0.10 \>gtg)
Date Source:  Canadian Department of Fisheries and Oceans

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                                          Total  DDT in  Smelt
Figure 12. Total DDT levels (ijg/gS.E.) in rainbow smelt whole fish (wet weight) in the Great Lakes, 1977-1992.
 >50% results below detection limit (0.01 \ig/g)
Data Source:  Canadian Department of Fisheries and Oceans

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                                        Mercury Trends in Smelt
Figure 13. Mercury levels (pg/gS.E.) in rainbow smelt whole fish (wet weight) in the Great Lakes, 1977-1992.
 >50% results below detection Bmit (0.03 \ig/g)
Data Source:  Canadian Department of Fisheries and Oceans

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                                       PCB (ng if1)
                                                              PCB (ng g' )
         I LAKE SUPERIOR I
                           KAU RIVER
                          MPICON BAY
         I LAKE ST.CLAiRl
         [DETROIT RIVER I
         F  LAKE ERIC !
         INIACARA RIVER I
                    FRENCHMAN? CREEK
                      WHEATriEUJ, N.Y.
                     102nd STREET. N.Y.
                    CAYUGA CREEK. N.Y.
                     SEARCH ft RESCUE
                        LEWISTON, N.Y.
                          OUEEKSTON
                  MAGARA-ON-THE-LAKE
                                      100 200 300 400 500
                                           II   I
  MITCHELL BAY
  THAMES RIVER
  PECHE ISLAND

  WINDSOR STP
FIGHTING ISLAND I
  AMHERSTBURG I
          LAKE HURONI NOTTAWASASA RIVER IN
                       .  COLUNGWOODI
                       UA1TIAHD RIVER  N
         IST.CLAIR RIVJ51 LAMtTON OEM STAT j
                       SOUTH CHANNEL  N
                           HG CREEK
                          LEAMINGTON I
                           WHEATLEY
                         GRAND RIVER | N
                    THUNDER BAY BEACH
                                                          0  100 200 300 400 SOO
                                                                  1    I    I
                                                            ILAKE ONTARIOI
                                              WtUAND CANAL I
                                            TWELVE MILE CREEK I
                                            BURUHGTON BEACH
                                                 CREDIT RIVER
                                             CTOBICOKE CREEK I
                                                HUMBER RIVER I
                                            TORONTO HARBOUR
                                                 ROUGE RIVER
                                             GANARASKA RIVER
                                                WOLFE ISLAND IN
IST.LAWRENCE RIVERI
      MACDONMELL ISLAND I
       BELOW HYDRO DAM
        CORNWALL MARINA
           nLON ISLAND
            RAISIN RIVER I
            BRASS RIVERJ
  REYNOLDS ALUMINUM, N.Y. I
          C.U.PLANT. N.Y. I
         RAOUETTE RIVER \
         - ST.  REGIS RIVER I
           SALMON RIVER
                                     ILAKE ST.FRANCIS|
                                             THOMPSON ISLAND I
                                            BUCHANNAN ISLAND
                                      tOO 200 300
                                                      500
                                                                                 0  100 200 300 400 500
                                   UC AQUATIC
                                  UFE GUIDELINE
                                                          UC AQUATIC
                                                         LIFE GUIDELINE
Figure 14.   Total PCB concentrations in young-of -the-year spottail shiners from the
                Great Lakes and connecting channels for the most recent year, 1990 or 1991.
                UC Aquatic Life Guideline for PCB = 100 ng/g. (N = not detected; T = trace)
               (Data Source: Karlis R. Suns, et al., Ontario Ministry of Environemnt and Energy)

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                                     PCB Trends in  Herring Gull  Eggs
Figure 15. PCB levels (\ig/g wet weightS.E.) in Herring Gull eggs in the Great Lakes, 1974-1993.
Data Source: Canadian Wildlife Service, adapted from Bishop et al. 1992 and Petti et al. 1994)

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                               p,p'-DDE Trends in Herring Gull  Eggs
Figure 16. p,p'-DDE levels (ug/g wet weightS.E.) in Herring Gull eggs in the Great Lakes,
Data Source: Canadian Wildlife Service. Adapted from Bishop et al. 1992 and Petit et al. 1994.

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              DIOXIN* IN HERRING GULL EGGS 1971 -1992
                          EASTERN LAKE ONTARIO
pg/g (ppt)W et W eight
  2500
  2000
  1500
  1000
   500
        71 72 73 74  75  76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92

   2,3,7,8 - tetra-chloro-benzo-dioxin


   Figure 17.   Dioxin (2,3,7,8-TCDD) Concentrations in herring gutl eggs from eastern Lake Ontario, 1971 -1992 (Data from C. Weseloh,
            Canadian Wildlife Service, adapted from Bishop et al. 1992, Petit et al. 1994, and Hebert et al., 1994).

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         Contaminants  in Herring Gull Eggs -1992
                        Spatial Distribution
 mg/kg (ppm) Wet
      Weight
30-i
25
20
15
10
 0
I
W
c -
"0
m
3D
O
30



(0
C
"0
m
3D
o
3D




0
Z*
o
^
"Z,




o
o
fr
z



3C
c
30
O
z




1
z
c
o




1 1
z o m
c m 3D
1 i s
 i



i i
m z o
2  > z
m o ^
i 5
> o




o
NTARI
O



1 T
(0
H
i
30
m
o
m
      Total PCBs
    HCB(X100)
  DDE
Dieldrin(XIO)
 Figure 18.   PCBs, DDE, and dieidrin in Herring Gull Eggs collected in 1992 from sites on each Great Lake and
           the Detroit, Niagara, and St. Lawrence Rivers. (Data from C. Weseloh, Canadian Wildlife Service,
           adapted from Bishop et al 1992 and Petit et al. 1994)

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          DIOXIN IN HERRING GULL EGGS - GREAT LAKES
                                          1992
Parts per Million
    L. Superior
L. Huron
L Michigan
L. Erie
L. Ontario
     Figure 19.    Dioxin (2,3,7,8-TCDD) concentrations in herring gull eggs collected in 1992 from sites on each Great Lake
               (Data from C. Wesetoh, Canadian Wildlife Service, adapted from Bishop et ai. 1992, Petit et al, 1994, and
               Hebertetal., 1994).

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         CONTAMINANTS IN HERRING GULL EGGS -1992
                      SPATIAL DISTRIBUTION
                                                                      Mrex
                                                                    QyCHotbre
                                                                  HeptacNor-^xodde
Figure 20.   Mirex and other contaminants in herring gull eggs collected in 1992 from sites on each Great Lake
         (data from C. Weseloh, Canadian Wildlife Service, adapted from Bishop et al. 1992 and Petit et'al. 1994).

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        ATMOSPHERIC PCBs, FALL AND SPRING, 1991  -1992
     LAKE SUPER OR
(in ng/m3)
                                                                        LAKE HURON
StationA  StationB   StationC  Station D
                                                                      Station A
                                                                                 Station B
LAKE ST. GLAIR/DETROIT RIVER
                                     LAKE ERIE
                                                                 2




                                                                1.5




                                                                 1




                                                                0.5




                                                                 0
                                                                      Station A
                                                                                  Station B
  LatoSlCWr      DeWtHver




 Figure 21.    Concentrations of PCBs in the air over the Great Lakes., 1991-1992 (Data from S. Eisenreich, personal Communication).

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