Full text of DOI:10.1016/S0380-1330(01)70658-2

J. Great Lakes Res. 27(4):434–448
Internat. Assoc. Great Lakes Res., 2001
Sediment Contamination in Lake Erie:
A 25-Year Retrospective Analysis
Scott Painter1*, Chris Marvin1, Fernando Rosa1, Trefor B. Reynoldson1, Murray N. Charlton1,
Michael Fox1, P.A. Lina Thiessen1 and John F. Estenik2
1Environment Canada
867 Lakeshore Road, PO Box 5050
Burlington, Ontario L7R 4A6
2Ohio Environmental Protection Agency
Lazarus Government Center, P.O. Box 1049
Columbus, Ohio 43216-1049
ABSTRACT. Lake Erie sediment surveys were conducted in 1997 and 1998 to characterize spatial and
temporal trends in contamination and for comparison with historical levels to assess the degree of
improvement in environmental quality since the advent of measures to reduce impacts from sources.
These surveys were also designed to assist in identification of possible sources of contamination and
areas where contamination exceeded Canadian sediment quality guidelines for protection of aquatic
biota. Encouragingly, lakewide contaminant concentrations were found to have significantly decreased
from levels observed in samples collected in 1971 in previous Environment Canada surveys. The lakewide
average polychlorinated biphenyl (PCB) sediment concentrations decreased from 136 ng/g in 1971 to 43
ng/g in 1997. This decreasing temporal trend was also evidenced by contaminant profiles of core samples
from all three major basins. There was a lakewide spatial trend in increasing sediment contamination
from the eastern basin to the western basin, and from the north-central basin to the south-central basin.
Sediments in many areas of Lake Erie still exceeded Canadian Federal and Provincial sediment quality
guidelines. However, exceedences of sediment guidelines describing contaminated environments in
1997/98 were largely restricted to the western basin and the southern portion of the central basin. Excee-
dences of Canadian Sediment Quality probable effects guidelines were most numerous for dioxins and
furans (40%) followed by mercury (6%). The Canadian threshold effects guideline for PCBs (34.1 ng/g)
and the Provincial lowest effect guideline (70 ng/g) were exceeded at 52% and 22% of the sites, respec-
tively. Mercury, PCBs and polychlorinated dibenzo-p-dioxins and dibenzofurans are responsible for fish
consumption advisories in Lake Erie.
INDEX WORDS: Lake Erie, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, mercury,
metals, sediment.
INTRODUCTION
In 1971, Environment Canada conducted a sur-
vey in Lake Erie to characterize the spatial extent of
sediment contamination by metals and organochlo-
rine contaminants using surficial sediment samples
(Frank et al. 1977, Thomas and Jaquet 1976,
Thomas et al. 1976). In addition, the cultural im-
pact of human activities over time was assessed
using sediment cores (Kemp and Thomas 1976,
Kemp et al. 1976). Sediment concentrations of met-
als including total mercury, lead, zinc, cadmium,
and copper were compared to pre-colonial concen-
trations; the highest total mercury concentrations
occurred in the western basin adjacent to the De-
The presence of persistent pollutants can ad-
versely impact Great Lakes wildlife, biodiversity,
and aquatic ecosystems. Environment Canada to-
gether with collaborating agencies routinely conduct
Great Lakes surveys to measure the occurrence and
spatial distribution of toxic substances, to further un-
derstanding of the role human activities play in re-
leasing these compounds to the environment, and to
provide information for devising effective strategies
to mitigate potentially deleterious health effects.
*Corresponding author: E-mail: Scott.Painter@cciw.ca
434

Sediment Contamination in Lake Erie
435
FIG. 1. Map of Lake Erie showing stations for sampling conducted in 1997 and 1998.
troit River; DDT was similarly distributed. Inputs
of PCBs were apparent along the southern shore
while dieldrin appeared to have sources along both
the south and north shores. A western basin core
sample indicated that PCBs and other organochlo-
rines began to accumulate in the sediments during
the period 1953 to 1958. In general, sediments in
the western basin of Lake Erie exhibited high levels
of contamination. Sediments in the central and east-
ern basins exhibited levels intermediate between
those in the western basin and lower levels in sedi-
ments in Lake St. Clair, which discharges into the
Detroit River.
In 1995, Environment Canada revisited 50 of the
original 259 sites from the 1971 survey. The 1995
sediment samples, as well as archived 1971 sam-
ples, were analyzed for PCBs and other organochlo-
rines. Encouragingly, the PCB and organochlorine
pesticide concentrations had decreased considerably
from those reported in 1971. Therefore, Environ-
ment Canada in collaboration with the Ohio Envi-
ronmental Protection Agency conducted additional
Lake Erie surveys in 1997 and 1998, to enable a
broader range of analyses for the assessment of cur-
rent sediment contamination relative to sediment
quality guidelines, as well as further documentation
of the improvement in sediment contaminant con-
centrations from the original 1971 survey. This
paper presents an overview of the spatial and tem-
poral characterization of sediment contamination in
Lake Erie using results from the 1971 and 1997/98
surveys. Trace metals, especially total mercury and
lead, nutrients, PCBs, and dioxins/furans are de-
scribed in this paper. More detailed discussions of
trends and spatial distributions of specific com-
pound classes, such as toxaphene, can be found in
other reports such as Marvin et al. 2000. The results
are presented within the context of Canadian Sedi-
ment Quality Guidelines (CCME 1999). These
guidelines are routinely applied as screening tools
in the assessment of potential risk and determina-
tion of the relative priority of sediment quality con-
cerns. Two benchmarks have been determined for a
number of contaminants. “The lower value, referred
to as the threshold effect level (TEL), represents the
concentration below which adverse biological ef-
fects are expected to occur rarely. The upper value,
referred to as the probable effect level (PEL), de-
fines the level above which adverse effects are ex-
pected to occur frequently” (CCME 1999).
METHODS
Sample Collection
Surficial sediment samples were collected aboard
the CCGS Limnos in 1997 from sixty-three loca-
tions (Fig. 1) using a mini box core sampling proce-
dure. The top 3 cm of the sediment were

436
Painter et al.
sub-sampled for the analyses of chlorinated organic
contaminants, total metals, grain size, and nutrients.
At three index stations, one in each of the western,
central, and eastern basins, both mini box core and
benthos gravity core samples were obtained for sur-
ficial sediment sampling and sediment depth pro-
files. Mini box cores were sub-sampled in 1 cm
increments from 0 to 15 cm, in 2 cm increments
from 16 to 30 cm, and in 5 cm increments to a
depth of 40 cm. Benthos gravity cores were sub-
sampled in 1 cm intervals from 0–1 cm, 9–10 cm,
14–15 cm, 19–20 cm, 29–30 cm, and every 10 cm
thereafter (i.e., 39–40 cm, 49–50 cm) to the bottom
of the core. Samples for organic contaminant analy-
ses were collected in pre-washed glass jars. Sam-
ples for other characterizations were collected in
either high density polypropylene or Teflon jars. All
samples were frozen immediately for transport to
the laboratory. In April 1998, additional sediment
samples were obtained for polychlorinated dibenzo-
p-dioxin and dibenzofuran analyses, in addition to
the previously identified parameters, using the mini
box core method described above. The 1998 survey
added six new sites resulting in a total of 69 sites;
not all sites were analyzed for all parameters.
PCB #30, PCB #204, 1,3,5-tribromobenzene,
1,2,4,5-tetrabromobenzene and δ-BHC. Recovery
criteria for surrogates were 70%; measurements of
SRMs were required to be within 30% of certified
values. Procedural blanks and surrogate recoveries
were also evaluated against criteria established by
the National Laboratory for Environmental Testing
(Environment Canada) resulting from replicate
analyses of SRMs over a 2-year period. Field repli-
cates were typically within 30%. An external cali-
bration method was employed for quantitation
using individual organochlorine standards and a
132-congener PCB standard from the National Lab-
oratory for Environmental Testing. Total PCB val-
ues are expressed as the sum of the following
congeners, numbered according to the method of
Ballschmiter and Zell (B/Z #): B/Z# 16, 24, 28, 31,
32, 44, 52, 74, 87, 99, 101, 110, 118, 138, 149, 163,
174, 180, 182, 187, 194, 195, 201, and 206.
Trace element, mercury, loss on ignition, and nu-
trient analyses were performed by Seprotech Labo-
ratories. Trace metal concentrations were
determined by a hot aqua-regia extraction with
measurement by ICP-AES (McLaren 1981). Total
mercury was determined by digestion with hot ni-
tric acid and hydrochloric acid followed with mea-
surement by cold vapor atomic absorption
spectrometer (USEPA 1981). Loss on ignition was
determined by igniting a sample at 1,000°C in a
porcelain crucible. Total nitrogen and phosphorus
were determined using United States Environmental
Protection Agency standard methods (USEPA
1981).
Analysis of polychlorinated dibenzo-p-dioxins
and furans was carried out in accordance with the
USEPA Method 1613B protocol for dioxins and fu-
rans (USEPA 1994) by Axys Analytical Services
Ltd (Sidney, British Columbia). Samples were
spiked with 13C-labelled surrogate standards.
Toluene sediment extracts were subjected to a se-
quential cleanup including an acid/base wash, alu-
mina column, carbon/celite column and a second
alumina column procedure. Analysis by high-reso-
lution gas chromatography—high resolution mass
spectrometry was carried out in selected ion moni-
toring (SIM) mode using a VG Ultima mass spec-
trometer equipped with a Hewlett-Packard 5890 gas
chromatograph. Chromatographic separation was
carried out using split/splitless injection on a 0.25
mm i.d. 60 m DB-5 column with a 0.25 μm station-
ary phase thickness. All congeners were reported
according to ion abundance ratio criteria, absolute
and relative retention times, and signal to noise ra-
Analyses
Frozen sediment samples were thawed followed
by air-drying of 5-gram subsamples. Dry sediment
samples were extracted in dichloromethane at
100°C and 2,000 psi using an Accelerated Solvent
Extractor (ASE, Dionex Inc.). Solvent extracts were
gently reduced in volume under nitrogen to a final
volume of 1 mL in iso-octane. Extracts were then
subjected to an open-column deactivated Florosil
[2g] cleanup procedure (National Laboratory for
Environmental Testing 1997). Elution of the col-
umn with 10 mL 50% pentane in dichloromethane
[fraction A] followed by 10 mL dichloromethane
[fraction B] resulted in two fractions for analysis.
Fraction A was treated with mercury to remove sul-
fur. Analyses were carried out on a Hewlett-
Packard Model 5890 gas chromatograph equipped
with dual columns (0.25 mm i.d. 0.25 μm stationary
phase DB-5 and 0.25 mm i.d. 0.25 μm stationary
phase HP-50) and dual electron capture detectors.
Procedural method blanks and standard reference
materials (SRMs) were processed with each set of
10 samples. The SRM used was Analytical Refer-
ence Material EC-5 (National Water Research Insti-
tute, Environment Canada). Surrogate standards
applied to sediment prior to extraction included

Sediment Contamination in Lake Erie
437
tios as outlined in EPA Method 1613B. Procedural
blanks and precision and recovery samples were
processed with each sample batch and all data for
individual samples were checked against surrogate
recoveries. Toxic equivalents (TEQ) were calcu-
lated using the International Toxicity Equivalency
Factor (ITEF) method (Van den Berg et al. 1998);
congeners present at levels lower than the method
detection limits were given zero values for TEQ
calculations.
RESULTS AND DISCUSSION
The metals data from the central (Table 1) and
eastern and western basins (Table 2) of Lake Erie
TABLE 1. Total trace metal, nitrogen, phosphorus, iron, manganese, and aluminum data from surficial
sediment samples in Central Lake Erie in 1997/98.
Lat
Lon
Depth
As
Cd
Cr
Cu
Pb
Ni
Zn
Hg
N
P
Fe
%
Mn
μg/g
Al
%
dec.deg. dec.deg. Site
Basin
cm Year μg/g μg/g μg/g μg/g μg/g μg/g μg/g μg/g μg/g μg/g
41.9892 –80.6414 947 Central 0–3 1997 ND 2.4 44.2 46.4 51.5 38.0 283.8 0.218 1750 713 3.2 586.8 1.2
42.1811 –80.3933 1048 Central 0–3 1997 2.3 ND 9.3 3.1 10.7 9.1 26.7 0.006 146 465 0.9 233.1 0.3
42.0917 –80.3894 1049 Central 0–3 1997 ND 2.7 46.3 41.3 58.9 39.8 302.7 0.204 1300 616 2.9 465.0 1.1
42.0919 –80.5169 1050 Central 0–3 1997 5.8 ND 12.8 10.3 14.2 20.0 51.1 0.020 367 583 2.0 263.8 0.6
42.2725 –80.6367 1051 Central 0–3 1997 1.2 ND
9.8 4.7 7.7 7.9 24.0 0.012 416 826 1.3 329.7 0.3
42.0022 –80.8781 1052 Central 0–3 1997 5.6 1.8 36.4 38.9 44.0 38.5 176.6 0.202 2160 855 3.0 790.9 1.4
41.9108 –80.9975 1055 Central 0–3 1997 4.3 2.8 57.5 56.6 76.0 50.4 317.9 0.284 2180 780 3.4 483.7 1.5
42.0033 –81.1197 1056 Central 0–3 1998 15.0 3.0 36.0 45.0 48.0 43.0 187.0 0.155 2770 593 3.5 975.0 1.4
42.3631 –81.1236 1057 Central 0–3 1998 ND 1.0 17.0 22.0 17.0 22.0 80.0 0.055 1440 698 2.7 368.0 0.8
41.9125 –81.2397 1058 Central 0–3 1997 ND 0.7 25.3 27.8 21.8 39.6 105.0 0.070 1620 610 3.0 422.1 1.4
42.1808 –81.2428 1059 Central 0–3 1997 ND 1.1 40.6 45.6 47.1 48.5 183.9 0.144 2540 980 3.5 849.6 1.9
41.8222 –81.3600 1060 Central 0–3 1997 5.2 1.6 52.8 52.9 59.3 55.5 239.6 0.274 3730 1040 4.0 1160.0 2.1
42.3614 –81.3639 1061 Central 0–3 1997 ND 1.6 38.0 44.2 50.4 49.2 166.8 0.122 3010 939 3.4 904.4 1.9
41.9106 –81.4833 1062 Central 0–3 1997 11.4 2.5 56.9 55.4 78.1 59.4 266.5 0.284 3860 945 3.8 844.9 2.1
42.0908 –81.4856 1063 Central 0–3 1997 8.9 1.1 46.2 45.6 54.6 51.5 208.3 0.170 2690 998 3.7 863.8 2.0
41.6400 –81.6042 1064 Central 0–3 1997 5.8 2.2 48.0 50.3 61.1 52.5 221.1 0.280 2760 953 3.9 725.5 1.7
41.8197 –81.6000 1065 Central 0–3 1997 18.6 1.7 56.3 56.3 81.1 58.2 263.0 0.326 3630 928 3.5 690.7 1.9
41.6400 –81.7222 1066 Central 0–3 1997 7.5 ND 44.5 68.2 104.3 41.7 243.8 0.184 2180 780 5.0 968.7 1.2
42.1803 –81.7244 1067 Central 0–3 1997 11.1 1.0 43.9 48.2 63.7 53.0 206.6 0.160 3510 1160 3.5 1070.0 1.7
41.5428 –81.8389 1068 Central 0–3 1997 9.6 1.1 46.7 47.0 49.7 51.7 195.1 0.252 3200 953 4.3 817.4 1.8
41.9069 –81.8442 1069 Central 0–3 1997 2.3 1.2 53.0 49.2 68.6 55.8 238.8 0.198 3620 1110 3.8 668.8 2.1
41.6381 –82.0847 1071 Central 0–3 1997 ND 1.8 53.4 55.5 65.5 56.4 223.3 0.340 3980 1030 3.6 872.5 1.9
41.8164 –82.0833 1072 Central 0–3 1997 4.7 2.1 56.5 56.7 73.6 60.4 249.0 0.270 4090 1180 3.9 1050.0 2.0
41.5433 –82.1992 1073 Central 0–3 1997 13.7 4.4 23.0 32.2 44.2 29.0 232.9 0.130 1630 438 2.8 402.9 0.8
41.9894 –82.2064 1074 Central 0–3 1997 1.5 2.0 55.7 59.8 87.5 61.9 262.5 0.236 4160 878 3.7 779.8 2.0
41.7214 –82.3239 1075 Central 0–3 1997 16.8 0.8 33.5 34.2 41.9 38.9 142.6 0.266 2590 700 2.2 498.1 1.1
41.4514 –82.4372 1077 Central 0–3 1997 4.0 1.5 43.8 47.3 45.1 49.5 173.4 0.306 3230 883 3.2 1030.0 1.8
41.6311 –82.5628 1079 Central 0–3 1997 ND 1.3 30.5 30.6 29.8 34.0 122.6 0.237 1950 598 2.1 443.5 1.0
41.5397 –82.6786 1080 Central 0–3 1997 ND 0.5 41.8 41.7 43.0 47.1 169.7 0.208 2640 828 2.9 640.5 1.7
41.4519 –82.5583 1090 Central 0–3 1997 8.0 1.9 44.3 49.2 46.2 49.9 176.0 0.183 3000 781 3.1 818.2 1.7
41.5433 –81.7206 1092 Central 0–3 1997 10.9 ND 10.0 8.1 13.1 16.3 52.3 0.023 271 343 2.2 307.0 0.4
41.6472 –81.4833 1093 Central 0–3 1997 15.6 ND 10.9 11.7 12.9 13.9 91.1 0.023 381 462 1.6 323.9 0.5
41.9108 –80.8750 1095 Central 0–3 1997 8.4 2.2 36.5 44.5 50.8 40.9 196.0 0.181 1360 578 3.0 507.2 1.1
42.9986 –81.6008 1098 Central 0–3 1997 14.5 0.7 45.8 44.1 59.9 51.7 204.2 0.164 3200 889 3.6 871.5 1.9
41.9981 –80.5178 1099 Central 0–3 1997 5.7 ND 17.7 25.7 22.4 25.7 117.4 0.072 1200 522 2.5 422.8 0.8
42.0856 –81.9664 1100 Central 0–3 1998 NA 1.0 17.0 21.0 39.0 42.0 118.0 0.025 345 771 6.5 1551.0 0.7
42.3547 –81.6053 1102 Central 0–3 1997 1.5 1.0 40.8 46.0 57.6 51.6 188.2 0.159 3190 870 3.4 1020.0 1.7
42.5372 –81.2394 1105 Central 0–3 1997 ND 2.0 20.1 20.9 12.1 29.8 88.7 0.052 2350 532 2.0 915.0 1.2
42.5394 –80.7558 1106 Central 0–3 1998 12.0 1.0
8.0 6.0 10.0 10.0 29.0 0.015 323 266 1.5 547.0 0.4
41.4958 –82.2006 1110 Central 0–3 1997 6.6 ND 11.7 13.0 10.7 17.9 83.3 0.031 642 680 3.8 439.1 0.5
41.5903 –81.6042 1111 Central 0–3 1997 ND 3.3 47.3 52.4 59.5 43.4 305.8 0.301 1420 630 3.5 512.3 1.2
42.0394 –80.3964 1112 Central 0–3 1997 14.8 ND 12.4 8.2 15.8 14.2 73.4 NA
388 450 1.8 315.3 0.7

438
Painter et al.
TABLE 2. Total trace metal, nitrogen, phosphorus, iron, manganese, and aluminum in surficial sedi-
ment samples from Eastern and Western Lake Erie.
Lat
Lon
Depth
As
Cd
Cr
Cu
Pb
Ni
Zn
Hg
N
P
Fe
%
Mn
μg/g
Al
%
dec.deg. dec.deg. Station Basin
cm Year μg/g μg/g μg/g μg/g μg/g μg/g μg/g μg/g μg/g μg/g
42.6192 –79.1700 1033
42.6214 –79.4139 1035
42.7114 –79.5350 1037
42.3564 –79.7867 1039
42.5333 –79.7833 1040
42.5378 –79.9075 1042
42.4478 –79.9056 1043
42.3581 –80.0272 1044
42.4472 –80.1483 1045
42.3589 –80.2744 1047
42.1742 –80.0239 1101
42.3561 –79.6514 1103
42.6233 –80.0206 1107
42.7167 –80.1414 1108
42.7986 –79.1650 1109
41.7967 –83.3175 973
41.9889 –82.6906 1081
41.8531 –82.7472 1082
41.9381 –82.8706 1083
41.6239 –82.9178 1084
41.8061 –82.9247 1085
41.7122 –83.0414 1086
41.8011 –83.1678 1088
41.8964 –83.2783 1089
41.5347 –82.9158 1091
41.9711 –83.1850 1096
41.9817 –83.0500 1097
East
East
East
East
East
East
East
East
East
East
East
East
East
East
East
West
West
West
West
West
West
West
West
West
West
West
West
0–3 1997 ND 0.9 21.7 16.2 23.6 20.7 121.2 0.062
744 527 2.1 234.8 0.7
0–3 1997 5.7 1.0 35.9 40.4 33.9 43.1 168.9 0.126 2000 787 3.3 771.4 1.6
0–3 1997 ND ND 26.0 24.7 25.3 31.5 109.5 0.072 1510 817 2.2 517.3 1.2
0–3 1997 0.7 1.2 43.1 37.7 49.2 54.7 198.4 0.136 2710 1040 3.7 1009.9 2.1
0–3 1997 12.0 0.7 37.3 38.2 36.5 45.2 165.5 0.097 2320 843 3.4 1206.6 1.8
0–3 1997 2.4 ND 32.0 32.6 25.5 39.0 130.9 0.072 1840 893 3.2 1120.0 1.8
0–3 1997 14.4 ND 34.0 33.3 25.8 40.5 137.3 0.086 1940 945 3.3 1140.0 1.9
0–3 1997 ND
0–3 1997 ND
0.8 22.4 26.2
1.1 25.9 32.6 32.1 35.5 112.2 0.084 2190 978 2.5 868.6 1.3
4.4 19.7 47.3 0.016 408 661 2.0 521.0 0.9
7.7 29.4 76.1 0.016
679 705 2.7 792.2 1.5
0–3 1997 12.0 ND 16.4 14.5
0–3 1997 15.6 ND 13.6 16.9 11.5 21.5 74.6 0.052 1470 405 1.8 432.5 0.7
0–3 1997 15.2 1.0 29.6 35.6 32.8 35.5 155.7 0.130 2020 673 2.8 505.7 1.2
0–3 1997 3.9 ND 24.7 24.9 12.0 28.5 90.3 0.045 1350 707 2.6 913.7 1.5
0–3 1997 1.7 ND 14.0 17.0
0–3 1997 8.6 ND 9.8 5.8 10.3 15.5 38.1 0.014
0–3 1998 ND
0–3 1998 10.0 2.0 41.0 44.0 42.0 40.0 158.0 0.458 2550 519 2.7 494.0 1.2
5.0 17.6 48.9 0.016
637 588 1.8 533.7 0.9
424 761 1.3 263.4 0.4
4.0 53.0 58.0 51.0 49.0 210.0 0.296 2480 711 3.4 649.0 1.6
0–3 1997 ND
0–3 1997 ND
0–3 1997 ND
1.0 61.4 48.0 66.4 54.7 226.6 0.365 2670 679 3.2 655.4 1.7
1.1 44.0 44.6 45.7 40.9 179.1 0.690 2240 639 2.6 488.0 1.3
0.9 55.1 45.6 47.9 53.5 209.5 0.225 2670 833 3.4 588.7 1.9
0–3 1997 13.4 1.0 56.5 45.5 57.1 49.0 204.9 0.638 2403 841 3.0 663.6 1.6
0–3 1997 ND 2.4 72.8 58.3 73.4 63.5 264.7 0.692 3020 863 3.6 702.7 1.9
0–3 1997 4.5 ND 16.2 10.4 15.3 15.1 61.5 0.076 449 319 0.8 130.7 0.3
0–3 1997 8.4 1.5 40.1 39.9 34.9 36.4 171.5 0.179 2330 761 2.2 471.6 1.2
0–3 1997 7.5 0.9 26.6 30.6 24.3 32.5 109.4 0.113 2210 700 2.2 481.4 1.2
0–3 1997 10.9 0.7 23.8 18.3 18.1 16.1 105.9 0.220
504 755 1.0 181.9 0.3
0–3 1997 ND 1.4 47.8 46.4 57.1 43.6 180.9 0.940 1860 623 2.5 450.5 1.2
were analyzed for spatial patterns to assist in identi-
fication of source areas, to identify areas of non-
compliance with Canadian Sediment Quality
Guidelines (Table 3), and, in conjunction with the
core data, to assess surficial sediment enrichment
compared to historical norms. Core profiles of trace
metals from all basins generally exhibited increas-
ing analyte concentration gradients from the surface
to depths of approximately 10 cm to 20 cm, de-
creasing gradients from 20 cm to 40 cm, and rela-
tively constant concentrations from approximately
40 cm to 50 cm to the bottom of the core. Sedimen-
tation rates from a number of studies were available
to assist in the interpretation of temporal trends
(Gottgens et al. 1999, Ritson et al. 1994, Kemp et
al. 1976, and Nriagu et al. 1979). Using informa-
tion from these studies, depths of 20 cm were esti-
mated to represent the period 1960 to 1965 in the
western basin core, 1965 to 1970 in the eastern
basin core, and 1955 to 1960 in the central basin
core. Gottgens et al. (1999) found the peak concen-
tration of mercury in a sediment core from the
western basin occurred at a depth of 15 cm that was
estimated to represent 1970.
Concentrations of total mercury were highest in
the western basin core and lowest in the eastern
basin core (Fig. 2). Total chromium exhibited a pat-
tern similar to mercury. Concentrations of total lead
were highest in the central basin core at depths
ranging from 10 cm to 30 cm, but decreased to val-
ues similar to the western basin core in more recent
sediments at the surface (Fig. 3). Surface total lead
concentrations were the lowest in the eastern core;
total zinc core profiles were similar to lead. Total
cadmium, copper, and nickel core profiles were
similar in that the lowest values were in the surfi-
cial sediments from the eastern basin core, and the
central and western basin cores had higher yet simi-
lar values in recent surficial sediments. Unlike the
metals, total nitrogen and phosphorus concentra-

Sediment Contamination in Lake Erie
439
TABLE 3. Lake Erie basin-specific background concentrations and percentages of stations exceeding
background, surficial basin-specific 75th percentiles, Canadian Sediment Quality Guidelines, and the
number of sites exceeding the guidelines. Values for dioxin represent sum totals for both polychlorinated
dibenzo-p-dioxins and dibenzofurans.
Background
Concentrations
Surficial vs
Background
Surficial
75th Percentile
Canadian Sediment Quality
Guidelines (CCME, 1999)
μg/g
% of sites
ex. Iron and Aluminum (%)
% Exceeding
μg/g
(μg/g)
Exceeding
West Center East
West Center East West Center East
TEL
5.9
PEL TEL PEL
Arsenic
Cadmium
Chromium
Copper
Iron
Lead
Manganese
Mercury
Nickel
Nitrogen
Phosphorus
Zinc
5.8
< 1
7.1
< 1
6.8
< 1
42
67
39
63
73
63
34
73
59
80
46
61
85
76
29
40
13
47
47
33
60
47
73
40
8.8
1.6
11.1 12.0
2.0
17
3.53
90
42
72
49
55
3
3
0
0
1.0 0.596
22.2
15.1
2.34
13.2
519
31
27
92
92
67
100
42
55.4
46.8
3.2
57.1
650
0.65
50.1
46.6 33.0
49.2 34.5
37.3
35.7 196.6
35.1
3.53
22.7
573
28.4
3.17
18.6
780
3.6
59.8 32.4
872 962
0.25 0.09 0.174 0.486
51.7 39.8 18* 35.9*
3.2
35
91.3
57
46
1
6
0.034 0.049 0.042
27.6 45.9 35.5
1,308 1,782 1,471
100
83
83
53 2,580 3,198 2,010
466
63.5 105.8
1.66 1.81
523
717
95.6
1.71
92
92
33
53
60
27
779
209
1.66
936
237
1.85 1.69
868
146 123.1 314.8
62
1
Aluminum
PCBs (ng/g)
Dioxin
(pg/gTEQs)
102
51
26
34.1
0.85
277
52
93
0
33
23
2
21.5
40
Total Dioxin (pg/g)
8,240 4,690
342
* There is no recommended Canadian Sediment Quality Guideline (CSQG) for nickel; interim sediment assessment val-
ues (freshwater TEL of 18 μg/g and PEL of 35.9 μg/g) have been published by Smith et al. (1996). Values for nickel are
not recommended CSQGs.
tions increased towards the surface of the core
(Figs. 4 and 5). Surficial sediment concentrations
were highest in the central basin core.
ther illustrate the impact of anthropogenic enrich-
ment. The average background concentrations for
total arsenic, cadmium, chromium, copper, lead,
nickel, zinc, and mercury were determined for each
basin. The surficial concentrations were compared
to their respective background concentrations and
an enrichment ratio for each metal was calculated.
The average enrichment ratio for the eight metals at
each site was computed and is illustrated in Figure
6. The spatial pattern of the average enrichment
ratio was enhanced to illustrate west to east trends
by analyzing the minimum and maximum ratios in
each of the basins and selecting breakpoints that
would provide a simple pattern for clarity. The east-
ern basin and the northeast portion of the central
basin were the least contaminated above back-
ground with average ratios less than 1.725. The
western basin was most contaminated above back-
ground with 6 of the 10 sites having average ratios
above 2.715. The central basin ratios were interme-
diate between the western and eastern basins. The
The western, central, and eastern basin back-
ground contaminant concentrations were deter-
mined from the average of the concentrations from
the 40 to 50 cm interval to bottom of each core
(Table 3). The percentages of stations exceeding
basin-specific background concentrations for each
chemical are also summarized in Table 3. The west-
ern basin had the highest percentage of excee-
dences, suggesting the greatest anthropogenic
impact has occurred in the western basin. More
than 40% of the stations in each of the basins have
elevated surficial concentrations for total mercury,
zinc, lead, phosphorus, nitrogen, manganese, cop-
per, chromium, and nickel. Total mercury had the
highest number of stations exceeding background
concentrations. Average background concentrations
were used to express the surficial concentrations as
a ratio above the background concentration to fur-

440
Painter et al.
FIG. 3. Profiles of total lead concentrations
(μg/g) in core samples from each of the three
major Lake Erie basins.
FIG. 2. Profiles of total mercury concentrations
(μg/g) in core samples from each of the three
major Lake Erie basins.
spatial pattern in the anthropogenic enrichment is
an indication of the influence of historical and pre-
sent day human activity. However, it is also an indi-
cation of substrate type. The spatial chemical
concentration patterns were comparable to the spa-
tial bottom sediment type distribution as described
by Thomas et al. (1976). Sediments dominated by
fine-grain silts and clays absorb contaminants more
effectively compared to sediments dominated by
sands, hence the spatial patterns of contaminants
are not only a function of proximity to source but
also substrate type.
The spatial pattern evident in the surficial enrich-
ment map was also evident in the individual chemi-
cal distribution maps. The highest total mercury
concentrations and greatest number of exceedences
of the Canadian Sediment Quality probable effects
level (PEL) were located in the western basin (Fig.
7). The 75th percentile for the western basin was
more than 20 times the background concentration,
meanwhile, it was only twice the background con-
centration in the eastern basin (Table 3). Stations
exhibiting the lowest concentrations and concentra-
tions less than the Canadian Sediment Quality
threshold effects level (TEL) were located in the
eastern basin and the northeast area of the central
basin. Figure 8 illustrates the 1971 surficial sedi-
ment total mercury concentrations reported by
Thomas and Jaquet (1976). Consistent with the
temporal trends apparent in the core profile, sedi-
ment concentrations have decreased with time
throughout the entire lake. In 1971, the 75th per-
centiles for mercury in the western, central, and
eastern basins were 1.72, 0.58 and 0.65 μg/g, re-

Sediment Contamination in Lake Erie
441
FIG. 4. Profiles of total nitrogen concentrations
(μg/g) in core samples from each of the three
major Lake Erie basins.
FIG. 5. Profiles of total phosphorus concentra-
tions (μg/g) in core samples from each of the three
major Lake Erie basins.
two locations and total zinc had one site with a con-
centration greater than the PEL, all in the southern
area of the central basin. Total cadmium concentra-
tions exceeded the PEL at two locations, one in the
western basin and one in the southern portion of the
central basin. However, each of these exceedences
was unique in location. In total, 10 stations exhib-
ited sediment levels that exceeded the Canadian
Sediment Quality PELs; 5 in western Lake Erie for
total mercury (4) and cadmium (1), and 5 in the
southern portion of the central basin for total ar-
senic (2), cadmium (1), lead (1), and zinc (1).
Total nitrogen (Fig. 11) and phosphorus (Fig. 12)
concentrations compared to Ontario Provincial Sed-
iment Quality Guideline lowest effect (LEL) and
severe effect (SEL) sediment concentrations (Per-
saud et al. 1993) depict a more widespread spatial
contamination compared to the trace metals. How-
spectively. Meanwhile the 75th percentiles were
0.65, 0.25, and 0.09 μg/g in 1997.
Figure 9 illustrates the pattern for surficial sedi-
ment total lead concentrations. Only a single site in
the southern portion of the central basin exceeded
the PEL. Total lead exceedences of the TEL were
more spatially extensive in the central basin and the
eastern basin, compared to total mercury. The 75th
percentiles were less than 4 times the background
concentrations (Table 3). Figure 10 illustrates the
1971 pattern for total lead reported by Thomas and
Jaquet (1976); lakewide concentrations have de-
creased over time which was consistent with the ob-
served trend in the core profile. Control measures
restricting the use of leaded gasoline have undoubt-
edly contributed to the observed decreases. Spatial
distributions of other metals exhibited patterns sim-
ilar to total lead. Total arsenic exceeded the PEL at

442
Painter et al.
FIG. 6. Map of Lake Erie showing surficial sediment enrichment by metals. Ratios
were calculated using surficial sediment concentrations and background concentrations
determined from the bottom of cores. Values represent the average of the ratios calcu-
lated for arsenic, cadmium, chromium, copper, nickel, lead, zinc, and mercury.
ever, none of the locations exceeded the provincial
SEL. The highest concentrations of both nutrients
were observed in the central basin, which was also
consistent with the core profiles.
The spatial pattern of polychlorinated dibenzo-p-
dioxins and dibenzofurans is presented using toxic
equivalents for a subset of the survey stations (Fig.
13). Toxic equivalents (TEQs) were calculated
using the International Toxicity Equivalency Factor
(ITEF) method (Van den Berg et al. 1998). The pat-
tern was similar to the metal spatial patterns. Table
3 shows the 75th percentile values of dioxins and
furans, expressed as both totals and TEQs, for each
of the three basins. The 75th percentiles for dioxin
FIG. 7. Lake Erie surficial sediment total mercury concentrations (μg/g) in samples
collected in 1997/98. The Canadian Sediment Quality threshold effect level (TEL) is
0.174 μg/g and the probable effect level (PEL) is 0.486 μg/g.

Sediment Contamination in Lake Erie
443
FIG. 8. Lake Erie surficial sediment total mercury concentrations (μg/g) in samples
collected in 1971. The Canadian Sediment Quality threshold effect level (TEL) is 0.174
μg/g and the probable effect level (PEL) is 0.486 μg/g.
and furan TEQs were 33, 23, and 2 pg/g TEQ for
the western, central, and eastern basins, respec-
tively. Only two locations were lower than the
Canadian Sediment Quality proposed TEL (0.85
pg/g) while 12 sites, or 40% of the stations, ex-
ceeded the proposed PEL (21.5 pg/g). The highest
levels of dioxins and furans were found at stations
in the western basin and the southern portion of the
central basin. Ongoing monitoring of suspended
sediments in Lake Erie has shown that the western
basin continues to be subjected to active loadings of
these contaminants, with the Detroit River impli-
cated as a primary vector. Fish consumption advi-
sories for dioxins and furans have been
implemented for some species in United States
waters.
FIG. 9. Lake Erie surficial sediment total lead concentrations (μg/g) in samples
collected in 1997/98. The Canadian Sediment Quality threshold effect level (TEL) is
35 μg/g and the probable effect level (PEL) is 91.3 μg/g.

444
Painter et al.
FIG. 10. Lake Erie surficial sediment total lead concentrations (μg/g) in samples col-
lected in 1971. The Canadian Sediment Quality threshold effect level (TEL) is 35 μg/g
and the probable effect level (PEL) is 91.3 μg/g.
Total polychlorinated biphenyl (PCB) concentra-
methodology enabling a direct and valid compari-
son. Further analysis of a subset of samples (N = 6)
showed that the total PCB values based on the sum
of 24 individual congeners reported in this study
represented 54 2.7% of a total PCB value based
on the sum of 131 individual congeners, quanti-
tated using a dual-column method and a mixed
congener analytical standard from the National
tions in 1997 (Fig. 14) showed a lake-wide de-
crease since 1971 (Fig. 15). Total PCB values are
based on the sum total concentrations of the 24
most predominant congeners. Levels reported for
the 1971 survey were generated from analysis of
frozen sediment archives. Therefore, the data for
both 1997 and 1971 were generated using the same
FIG. 11. Lake Erie surficial sediment total nitrogen concentrations (μg/g) in samples
collected in 1997/98. The Province of Ontario Sediment Quality lowest effect level (LEL)
is 550 μg/g and the severe effect level (SEL) is 4,800 μg/g.

Sediment Contamination in Lake Erie
445
FIG. 12. Lake Erie surficial sediment total phosphorus concentrations (μg/g) in sam-
ples collected in 1997/98. The Province of Ontario Sediment Quality lowest effect level
(LEL) is 600 μg/g and the severe effect level (SEL) is 2,000 μg/g.
Laboratory for Environmental Testing (Environ-
ment Canada).
The PCB totals from eight stations in the western
basin were on average within 30% of the values re-
ported by Frank et al. (1977) using a packed-
column method, indicating that there were no ap-
preciable losses of analytes during the prolonged
frozen archive storage period. Levels of PCB conta-
mination were observed to have decreased from a
lakewide average value of 136 ng/g to 43 ng/g in
1997. The 1997 75th percentiles were 102, 51, and
26 ng/g in the western, central, and eastern basins,
FIG. 13. Lake Erie surficial sediment dibenzo-p-dioxin and dibenzofuran concentra-
tions (pg/g TEQ) in samples collected in 1997/98. The proposed Canadian Sediment
Quality threshold effect level (TEL) is 0.85 pg/g and the probable effect level (PEL) is
21.5 pg/g.

446
Painter et al.
FIG. 14. Lake Erie surficial sediment polychlorinated biphenyl concentrations (ng/g)
in samples collected in 1997/98. The Canadian Sediment Quality threshold effect level
(TEL) is 34.1 ng/g and the probable effect level (PEL) is 277 ng/g. The Province of
Ontario lowest effect level (LEL) is 70 ng/g.
respectively. Meanwhile, the 1971 75th percentiles
were 343, 128, and 99 ng/g, respectively. None of
the stations surveyed in 1997 exceeded the Cana-
dian PEL for total PCBs, compared to three areas
off the mouth of the Detroit River in 1971. In 1997,
30 sites, or 52% of the stations, exceeded the Cana-
dian TEL and 13 sites (22%) exceeded the Ontario
provincial LEL. Those sites exceeding the Ontario
provincial LEL were in the western basin and
southern portion of the central basin.
FIG. 15. Lake Erie surficial sediment polychlorinated biphenyl concentrations (ng/g)
in samples collected in 1971. The Canadian Sediment Quality threshold effect level
(TEL) is 34.1 ng/g and the probable effect level (PEL) is 277 ng/g. The Province of
Ontario lowest effect level (LEL) is 70 ng/g.

Sediment Contamination in Lake Erie
Temporal trends in total PCB contamination
447
were further defined through analyses of core sam-
ples (Fig. 16). The western basin (Station 1085)
core profile was distinct; there was a marked in-
crease in contamination from 30 cm to a depth of
20 cm representing the mid 1950s and 1960s. Con-
sistent total PCB concentrations were detected to a
depth of 6 cm where concentrations began a trend
toward decreasing concentrations to the top of the
core. The maximum total PCB contamination in the
central basin (Station 1098) core occurred at the 17
to 18 cm interval. There was a bimodal distribution
in the central basin core profile, and a trend toward
decreasing total PCB contamination in the top 6 cm
of the core similar to the western basin core. The
eastern basin (Station 1040) core profile was more
difficult to interpret; concentrations of total PCBs
in this core were consistent with depth and repre-
sentative of ambient background levels.
SUMMARY AND CONCLUSIONS
The observed spatial trends in sediment contami-
nation in Lake Erie were similar for a number of
compound classes including total PCBs, polychlori-
nated dibenzo-p-dioxin and dibenzofuran TEQs,
total mercury, and metals. There was a trend toward
increasing contamination from the eastern basin to
the western basin, and from the northern portion of
the central basin to the southern portion of the cen-
tral basin. Presumably, these trends were influenced
by industrial activities in the watersheds along
major tributaries including the Detroit River, and
areas along the southern shoreline. Other major in-
fluences in the observed trends may have included
prevailing currents, sediment transport and deposi-
tion processes, open-lake disposal of dredged mate-
rial, and remediation of contaminated areas. Frank
et al. (1977) reported that trends in total PCB and
total mercury contamination in the western basin
were attributable to the outflow from the Detroit
River in west bank, center bank, and east bank
water masses. It was not possible to infer any such
source information in this study because of the de-
creased sampling intensity compared to the 1971
study. However, Environment Canada monitoring
of suspended sediment quality in Lake Erie has
shown that the western basin continues to be sub-
jected to active loadings of contaminants. The De-
troit River has been identified as a primary vector
for these contaminants, but potential loadings from
other tributaries cannot be discounted. In addition,
FIG. 16. Profiles of polychlorinated biphenyl
levels (ng/g) in core samples from each of the
three major Lake Erie basins.
atmospheric deposition may have contributed to
these loadings.
Concentrations of contaminants in Lake Erie sed-
iments have decreased significantly over the period
1971 to 1997/98. This trend is also evidenced by
the profiles of core samples from the three major
basins. Sediments in many areas of Lake Erie still
exceeded the strictest Canadian and Province of
Ontario Sediment Quality Guidelines as defined by
the threshold effect level (TEL) or lowest effect
level (LEL), respectively. However, exceedences of
sediment guidelines describing contaminated envi-
ronments (probable effect level [PEL] and severe
effect level [SEL]) in 1997/98 were largely re-
stricted to the western basin and the southern por-
tion of the central basin. Exceedences of Canadian
Sediment Quality probable effects guidelines (PEL)
were most numerous for dioxins and furans (40%)

448
Painter et al.
Nriagu, J.O., Kemp, A.L.W., Wong, H.K.T., and Harper,
N. 1979. Sedimentary record of heavy metal pollution
in Lake Erie. Geochim. Cosmochim. Acta 43:247–258.
Persaud, D., Jaagumagi, R., and Hayton, A. 1993. Guide-
lines for the protection and management of aquatic
sediment quality in Ontario. Ontario Ministry of Envi-
ronment. Toronto.
Ritson, P.I., Esser, B.K., Niemeyer, S., and Flegal, A.R.
1994. Lead isotopic determination of historical
sources of lead to Lake Erie, North America.
Geochim. Cosmochim. Acta 58:3297–3305.
Smith, S.L., MacDonald, D.D., Keenleyside, K.A., Inger-
soll, C.G., and Field, L.J. 1996. A preliminary evalua-
tion of sediment quality assessment values for freshwa-
ter ecosystems. J. Great Lakes Res. 22(3):624–638.
Thomas, R.L., and Jaquet, J.-M. 1976. Mercury in the
surficial sediments of Lake Erie. J. Fish. Res. Board
Can. 33:404–412.
followed by mercury (6%). The Canadian threshold
effects guideline (TEL) for PCBs and the Provincial
lowest effect guideline (LEL) were exceeded at
52% and 22% of the sites, respectively. The pollu-
tants identified as exceeding various guidelines,
mercury, PCBs, and dioxins and furans, are respon-
sible for the fish consumption advisories in Lake
Erie.
REFERENCES
Canadian Council of Ministers of the Environment
(CCME). 1999. Canadian Environmental Quality
Guidelines. Winnipeg, Manitoba.
Frank, R., Holdrinet, M., Braun, H.E., Thomas, R.L.,
Kemp, A.L.W., and Jaquet, J.-M. 1977. Organochlo-
rine insecticides and PCBs in sediments of Lake St.
Clair (1970 and 1974) and Lake Erie (1971). Sci.
Total Environ. 8:205–227.
Gottgens, J.F., Rood, G.E., Delfino J.J., and Simmers,
B.S. 1999. Uncertainty in paleoecological studies of
mercury in sediment cores. Water, Air, Soil Pollut.
110:313–333.
Kemp, A.L.W., and Thomas, R.L. 1976. Impact of man’s
activities on the chemical composition in the sedi-
ments of Lakes Ontario, Erie, and Huron. Water, Air,
Soil Pollut. 5:469–490.
, Jaquet, J.-M., Kemp, A.L.W., and Lewis, C.F.M.
1976. Surficial sediments of Lake Erie. J. Fish. Res.
Board. Can. 33:385–403.
———
United States Environmental Protection Agency
(USEPA). 1981. Procedures for Handling and Chemi-
cal Analysis of Sediment and Water Samples. Envi-
ronmental Laboratory, US. Army Engineer Water-
ways Experiment Station, Vicksburg, Mississippi pp.
3–118.
. 1994. Method 1613: Tetra- through octa-chlori-
———
, Thomas, R.L., Dell, C.I., and Jaquet, J.-M. 1976.
———
nated dioxins and furans by isotope dilution
HRGC/HRMS. Office of Water, Engineering and
Analysis Division (4303), Washington, D.C.
Cultural impact of the geochemistry of sediments in
Lake Erie. J. Fish. Res. Board Can. 33:440–462.
Marvin, C., Painter, S., Charlton, M.C., and Backus, S.
2000. Spatial distribution of toxaphene in Lake Erie
sediments. Organohalogen Compounds 47:260–263.
McLaren, J.W. 1981. Simultaneous Determination of
Major, Minor, and Trace Elements in Marine Sedi-
ments by Inductively Coupled Plasma Atomic Emission
Spectrometry. Analytical Chemistry Section, Chem-
istry Division, National Research Council of Canada,
Ottawa, Ontario, Canada.
Van den Berg, M., Birnbaum, L., Bosveld, B.T.C., Brun-
strom, B., Cook, P., Feeley, M., Giesy, J.P., Hanberg,
A., Hasegawa, R., Kennedy, S.W., Kubiak, T.,
Larsen, J.C., Rolaf van Leeuwen, F.X., Liem, A.K.D.,
Nolt, C., Peterson, R.E., Poellinger, L., Safe, S.,
Schrenk, D., Tillitt, D., Tysklind, M., Younes, M.,
Waern, F., and Zacharewski, T. 1998. Toxic equiva-
lency factors (TEFs) for PCBs, PCDDs, PCDFs for
humans and wildlife. EHS-WHO Draft document.
National Laboratory for Environmental Testing. 1997.
Manual of Analytical Methods, Volume 3, Organics.
Canada Centre for Inland Waters, Environment
Canada, Burlington, Ontario, Canada.
Submitted: 31 January 2001
Accepted: 7 June 2001
Editorial handling: Ronald Rossmann