Report
Kurunthachalam Kannan, Simonetta Corsolini, Takashi Imagawa,
Silvano Focardi and John P. Giesy
Polychlorinated -Naphthalenes, -Biphenyls,
-Dibenzo-p-dioxins, -Dibenzofurans and
p,p’-DDE in Bluefin Tuna, Swordfish,
Cormorants and Barn Swallows from Italy
Concentrations of p,p’-DDE, polychlorinated biphenyl
congeners (PCBs), polychlorinated-dibenzo-p-dioxins
(PCDDs), -dibenzofurans (PCDFs) and -naphthalenes
(PCNs) were measured in bluefin tuna, swordfish, common
cormorants, and barn swallows collected from Italy. Average concentrations of PCBs in livers of tuna, swordfish,
cormorant, and swallows were 930, 745, 1420 and 1230
ng PCBs g–1, w.w. respectively. p,p’-DDE was found in
tuna, swordfish, cormorant, and swallow livers at mean
concentrations of 82, 135, 166 and 95 ng DDE g–1, w.w.
respectively. PCNs were found in all the samples analyzed,
although at concentrations less than those reported for
biota from the Baltic Sea. PCBs, particularly, non-ortho
coplanar PCBs accounted for 80–90% of the total TEQs
in tuna and swordfish. Relative contribution of PCDDs/DFs
to TEQs was greater in cormorants and swallows compared to that in fishes. PCDD/DF congeners accounted for
up to 80 and 45% of the total TEQs in cormorants and
swallows, respectively.
INTRODUCTION
Notable concentrations of polychlorinated biphenyls (PCBs) and
DDT have been reported in tissues of dolphins found stranded
along the Italian coast of the Mediterranean Sea (1-3). Concentrations of PCBs reported in the blubber of cetaceans from the
Italian coast of the Mediterranean Sea were greater than a threshold value, to elicit physiological effects in aquatic mammals of
11 µg g–1, w.w. (4). While studies have measured concentrations
of PCBs and DDTs in cetaceans, exposure to these compounds
in other coastal species, particularly tuna, swordfish, and cormorants is less known. Monitoring of contaminants is essential
in view of the fact that the tuna fishery is a major commercial
industry in coastal Italy. Consumption of tuna or swordfish containing high concentrations of PCBs or other toxic compounds
may have implications for human health. Apart from PCBs and
DDTs, no studies have reported concentrations of polychlorinated-dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs) or naphthalenes (PCNs) in fishes from the Italian coast. Furthermore, bird species such as cormorants and swallows have been
used as indicators to monitor aquatic pollution by chlorinated
organics (5, 6). The objectives of this study were to determine
concentrations and congener profiles of organochlorines that
elicit dioxin-like toxicity, and their corresponding toxic equivalents in fishes and birds from the Italian coast of the Mediterranean Sea using high resolution gas chromatography–high resolution mass spectrometry. Tissues of bluefin tuna (Thunnus
thynnus thynnus), swordfish (Xiphias gladius), and common cormorants (Phalacrocorax carbo) collected from the Italian coasts
were analyzed for the presence of p,p’-DDE, PCBs, PCDDs,
PCDFs and PCNs. Barn swallows (Hirundo rustica) collected
from agricultural areas in Pianura Padana near Milan, northern Italy, were analyzed for the presence of the target organochlorines. 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents
(TEQs) were calculated by multiplying the concentrations of
Ambio Vol. 31 No. 3, May 2002
toxic congeners with their corresponding toxic equivalency factors (TEFs) derived from H4IIE in vitro bioassays (7–9).
MATERIALS AND METHODS
Samples of liver, muscle and fat from sexually mature (fork
length > 110 cm) bluefin tuna were collected in Palizzi, southern coast of Italy, during October–November 1999. Total length
and weight of tuna ranged from 149 to 171 cm and 46 to 61 kg,
respectively. Liver and muscle were taken from mature swordfish, which were harpooned in Stretto di Messina in the Ionian—
Tyrrhenian Seas during July 1999. Heavy ship traffic is a major
source of pollution in the Stretto di Messina. Total length and
weight of swordfish ranged from 107 to 190 cm and 15 to 83
kg, respectively. Tissues from several individuals were pooled
to obtain representative samples. Livers of cormorants were collected from the birds that were originally sacrificed in 1997 by
the Department of Sanitation, Division of Rearing and Zootechnical Resources. Cormorants were collected near Oristano
(West coasts of Sardinia Island) in the vicinity of Cabras lagoon
in the Sardinian Sea. It is a protected area and is less polluted.
Barn swallows were collected during July–September 1995 at
farms located in Pianura Padana near Milan. Pianura Padana is
a large area in northern Italy characterized by intensive farming. The barn swallows collected at the nests were 1–2-years old
and were between 165 and 118 g total weight. Tissues were
wrapped in clean aluminum foil or whirlpac bags and stored frozen at –20°C until analysis. Sampling locations of fishes and
birds are shown in Figure 1. The sampling locations, in general,
are background sites with no known point sources of pollution.
CHEMICAL ANALYSIS
Chloronaphthalene (CN), chlorobiphenyl (CB) and 2,3,7,8-substituted congeners of PCDDs and PCDFs were analyzed followFigure 1. Map of Italy showing sampling locations of
fishes and birds.
© Royal Swedish Academy of Sciences 2002
http://www.ambio.kva.se
207
ing the method described elsewhere (10) with some modifica- PCN, PCDD and PCDF congeners through the analytical protions. Samples were homogenized with sodium sulfate and cedure were between 90 and 100%. Procedural blanks were
Soxhlet extracted with methylene chloride and hexane (3:1, 400 analyzed throughout the whole analytical procedure to check for
ml) for 16 hrs. The extract was rotary evaporated at 40°C and interferences. The detection limits of individual PCN and PCB
an aliquot was used for the determination of fat content by congeners varied depending on the sample masses, response facgravimetry. The remaining extract was spiked with 13C-TCDD, tors and interferences. Generally, detection limits for individual
13
C-TCDF, 13C-OCDD and 13C-OCDF as internal standards and congeners were 1 to 75 pg g–1, on a wet weight basis. Quality
interferences removed by fractionation with multilayer silica gel control criteria for positive identification of target compounds
column. The multilayer silica gel column was prepared by pack- included signal to noise ratio above 3, isotope ratios of the 2
ing a glass column (20 mm i.d.) with a series of layers of silica monitored ions for each compound within 15% of the theoretigel in the following order: 2 g silica, 6 g 40% acidic-silica, 2 g cal chlorine values, and that the compound should elute at the
silica and a thin layer of sodium sulfate at the top. The column same GC retention time as the standards. CN and CB congeners
was cleaned with 150 ml of hexane prior to the transfer of sam- are represented by using their IUPAC numbers throughout this
ple extracts. Samples were then eluted with 200 ml of hexane report (12, 13).
and rotary evaporated to 5 ml. A portion of the aliquot was taken
for the analysis of PCB congeners other than non-ortho coplanar RESULTS AND DISCUSSION
PCBs. The remaining samples were passed through a glass column (10 mm i.d.) packed with 1 g silica gel impregnated car- Bluefin Tuna
bon (Wako Pure Chemical Industries, Tokyo, Japan) for the sepa- Concentrations of total PCBs in livers of bluefin tuna ranged
ration of ortho-substituted PCBs from PCNs and PCDDs/DFs. from 224 to 1660 ng g–1 (mean: 934; n = 3) on a wet weight
The first fraction, which was eluted with 150 ml of hexane con- basis (w.w.) (Table 1). The 6-fold variation in the concentrations
tained major PCB congeners, which interfere with the analysis of total PCBs in tuna livers was related to lipid content. Lipidof PCNs and PCDDs/DFs. The second fraction, which was eluted normalized concentrations of total PCBs in tuna livers were bewith 200 ml of toluene contained non-ortho substituted PCB con- tween 5670 and 14␣ 400 ng g–1. Mean concentrations of total
geners—77, 126 and 169—, PCNs and PCDDs and PCDFs.
PCBs in tuna muscle and fat were 280 (n = 2) and 817 ng g–1,
PCB congeners were identified and quantified using a gas w.w., respectively. Concentrations of total PCBs in bluefin tuna
chromatograph (Perkin Elmer series 600) equipped with 63Ni collected from the Ionian and Tyrrhenian Seas in the late 1970s
electron capture detector (GC-ECD). A fused silica capillary col- ranged from 4.7 to 5000 ng g–1, w.w. (14). Similarly, muscle of
umn coated with DB-5MS ((5%-phenyl)-methylpolysiloxane, 30 bluefin tuna collected in 1993 contained total PCB concentram x 0.25 mm i.d.; J&W Scientific, Folsom, CA, USA) having a tions in the range of 170 to 2200 ng g–1, w.w. (1). Concentrafilm thickness of 0.25 µm was used. PCB congeners were iden- tions of total PCBs in tuna muscle analyzed in this study were
tified against a standard mixture containing 100 congeners of less than those reported earlier. However, it should be noted that
known composition and content. Further details of PCB analy- tuna analyzed in this study were smaller (46 to 61 kg) than those
sis are reported elsewhere (10, 11). Identification and quantifi- analyzed in earlier studies (70 to 400 kg) (1), which could have
cation of individual PCN and PCDD/DF congeners were accom- contributed to the observed temporal differences in total PCB
plished with a Hewlett Packard 6890 series high resolution gas concentrations.
chromatograph (HRGC) coupled to a JEOL JMS-700 high resoHexachlorobiphenyl no. 153 (2,2',4,4',5,5'-HxCB) was the
lution mass spectrometer (HRMS). PCN congeners, hepta- and most predominant congener found in tuna tissues (Table 2). This
octa-chlorodibenzo-p-dioxins and furans and non-ortho coplanar congener accounted for, on average, 20% of the total PCB conPCBs were separated using a DB-1701 column. Tetra- through centrations in tuna tissues. In a sample of tuna liver,
hexa-chlorodibenzo-p-dioxins and furans were separated by a heptachlorobiphenyl no. 180 (2,2',3,4,4',5,5'-HpCB) accounted
capillary column coated with SP-2331. The column oven tem- for the greatest proportion of total PCB concentrations (Table
perature was programmed from 80 to 160°C at a rate of 40°C 2). A few earlier studies have reported the occurrence of elevated
min–1 and then to 170°C at 10°C min–1, to 250°C at 4°C min–1 proportions of congener 180 in livers and blubbers of striped
and then to 296°C at 8°C min–1 with a final hold time of 10 min. dolphins from the Italian coast of the Tyrrhenian Sea (2, 3). CB
Injector and transfer line temperatures were held at 260 and congener 180 accounts for approximately 10% of the total PCBs
250°C, respectively. Helium was used as the carrier gas. The by weight in Aroclor 1260 (15). This congener accounted for,
mass spectrometer was operated at an electron impact (EI) en- on average, 10% of the total PCBs in the tissues of tuna. This
ergy of 70 eV. CN and dioxin congeners were determined by selected
ion monitoring (SIM) at the 2 most
intensive ions of the molecular ion
Table 1. Concentrations (wet weight) of p,p’-DDE (ng g–1), total PCBs (ng g–1) and total
cluster. A mixture of Halowaxes
PCNs (pg g–1) in fishes and birds from Italy.
1001, 1014, and 1051 containing all
Species
Tissue
Fat (%) Collection date
Location
N
p,p’-DDE PCBs
PCNs
the tri- through octa-chloronaphthaTunafish
Liver
11.5
Oct–Nov 1999
Palizzi
1
75
1660
NA
lenes was used as a standard for the
Tunafish
Liver
3.95
Oct–Nov 1999
Palizzi
1
61
224
53.8
quantification of PCNs. PCDD and
Tunafish
Liver
10
Oct–Nov 1999
Palizzi
5
110
920
NA
Tunafish
Muscle
5.3
Oct–Nov 1999
Palizzi
3
67
363
22.6
PCDF congeners were quantified
Tunafish
Muscle
2.92
Oct–Nov 1999
Palizzi
2
30
197
6.97
by comparing individually resolved
Tunafish
Fat
85
Oct–Nov 1999
Palizzi
3
135
817
552
Swordfish
Liver
16.2
July
1999
Stretto
Messina
4
135
745
62.9
peak areas to the corresponding
Swordfish
Muscle
8.78
July 1999
Stretto Messina 4
45
258
14.8
peak areas of the standards. RecovSwordfish
Muscle
9.5
July 1999
Stretto Messina 6
69
399
14.6
13
Cormorant
Liver
7.6
1997
Cabras lagoon
3
164
722
130
eries of C-labelled PCDDs/DFs,
Cormorant
Liver
7.76
1997
Cabras lagoon
1
190
2300
795
Cormorant
Liver
4.55
1997
Cabras lagoon
1
144
1230
347
which elute in the second fraction
Swallow
Liver
4.5
1995
Milan
5
84
954
215
containing PCNs and non-ortho
Swallow
Liver
6.2
1995
Milan
4
105
1510
126
Swallow
Muscle
4.7
1995
Milan
4
67
733
116
coplanar PCBs, were 77–95%. ReSwallow
Muscle
5.1
1995
Milan
5
82
700
142
ported concentrations were not corN=
number
of
samples
pooled.
rected for the recoveries of the inNA= not analyzed.
ternal standard. Recoveries of PCB,
208
© Royal Swedish Academy of Sciences 2002
http://www.ambio.kva.se
Ambio Vol. 31 No. 3, May 2002
Concentrations of 2,3,7,8-substituted congeners of PCDDs/
DFs were generally less than the limits of detection, which varied from 1 to 75 pg g–1, w.w., depending on the congeners and
tissue (Table 3). PCDD/DF congeners that were detected in tuna
tissues include, 2,3,4,7,8-PeCDF and 1,2,3,4,7,8-HxCDF, which
were found in a sample of tuna fat at concentrations of 19–20
pg g–1, w.w. Previous studies have not reported concentrations
of PCDDs/DFs in tuna from the Italian coast of the Mediterranean Sea. Nevertheless, concentrations of PCDDs/DFs in livers
of dolphins from the Mediterranean Sea have been reported to
range from 13 to 107 pg g–1, w.w. (19).
suggests exposure of tuna to highly chlorinated PCB mixtures
and/or selective retention of congener 180 in fish tissues. Congener 180 has been shown to be resistant to metabolism by marine animals (16). Overall, hexa- and hepta-chlorobiphenyl congeners 153, 138, 180, and 170, collectively accounted for 35 to
47% of the total PCB concentrations in tuna tissues.
Mean concentrations of p,p’-DDE in liver, muscle and fat of
tuna were 82, 49 and 135 ng g–1, w.w., respectively (Table 1).
The observed concentrations of p,p’-DDE in the muscle of tuna
were less than those reported for relatively larger size tuna collected in 1993 (56–270 ng g–1, w.w.) (1).
Polychlorinated naphthalenes were found in all the analyzed
tissues of bluefin tuna at concentrations ranging from 7 (muscle) to 550 pg g–1, w.w. (fat) (Table 1). The observed concentrations of PCNs were 3 to 5 orders of magnitude less than total
PCB concentrations. Tuna fat contained the highest concentration of PCNs. In this tissue, 17 of the 75 PCN congeners were
found. CN congeners 54 (1,2,3,6,7-PeCN), 56 (1,2,3,7,8-PeCN),
66/67 (1,2,3,4,6,7-/1,2,3,5,6,7-HxCNs), 61 (1,2,4,6,8-PeCN) and
52/60 (1,2,3,5,7-/1,2,4,6,7-PeCNs) were the predominant congeners collectively accounting for 84% of the total PCN concentrations in tuna fat. Concentrations of PCNs (1360 pg g–1, lipid weight (l.w.) in tuna livers were greater than those reported
for cod livers (388 pg g–1, l.w.) collected in 1998 from the Arctic Ocean (17). However, the observed concentrations of PCNs
in livers of tuna from Italy were less (1360 pg g–1, l.w.) than those
found in the livers of cod from the Baltic Sea (9800 pg g–1, l.w.)
(18).
Swordfish
Concentrations of total PCBs in pooled samples of liver and
muscle of swordfish were 745 and 329 ng g–1, w.w., respectively
(Table 1). Similarly, concentrations of p,p’-DDE in swordfish
liver and muscle were 135 and 57 ng g–1, w.w., respectively. The
observed concentrations of PCBs and p,p’-DDE in swordfish tissues were similar to those found in bluefin tuna. Similarly, profiles of PCB congeners in swordfish were similar to those observed for bluefin tuna. Hexachlorobiphenyl congener 153 accounted for the greatest proportion of total PCBs (20%) followed
in order by 180 (12%) and 138 (7%) (Table 2). PCNs were also
found in swordfish tissues at concentrations of 15 pg g–1, w.w.,
in muscle and 63 pg g–1, w.w., in liver. Tri-CN congeners 14/16
(1,2,4-/1,4,6-TrCNs) were the most abundant in swordfish. These
congeners collectively accounted for 50% of the total PCN concentrations. PCDD/DF congeners were not found in swordfish
Table 2. Concentrations of PCB congeners (w.w.) including non- (pg g–1), mono- (ng g–1) and di-ortho PCBs (ng g–1) in tuna, swordfish,
cormorant and swallow tissues from Italy.
Sample
Tissue
Tunafish
Tunafish
Tunafish
Tunafish
Tunafish
Tunafish
Swordfish
Swordfish
Swordfish
Cormorant
Cormorant
Cormorant
Swallow
Swallow
Swallow
Swallow
Non-ortho PCBs
(pg g–1)
N
Fat (%)
(pool)
Liver
Liver
Liver
Muscle
Muscle
Fat
Liver
Muscle
Muscle
Liver
Liver
Liver
Liver
Liver
Muscle
Muscle
1
1
5
3
2
3
4
4
6
3
1
1
5
4
4
5
11.5
3.95
10
5.3
2.92
85
16.2
8.78
9.5
7.6
7.76
4.55
45
6.2
4.7
5.1
Mono-ortho PCBs
(ng g–1)
Di-ortho PCBs (ng g-1)
Total
PCBs
77
126
169
105
118
156
137
138*
153
170
180
194
153
31.5
NA
71.7
23.8
518
82
48.8
490
44.5
98
NA
2940
8790
6330
2470
212
458
293
82.2
40.4
1010
134
60.8
68.6
212
428
NA
567
554
433
480
<23
<7.2
NA
9.2
5.7
62
<26
11
11
20
31
NA
62
39
53
66
25
3.27
7.2
5
2.7
9.5
8.4
2.5
4.5
19
44
29
26
15
14
19
87
7.4
32
14
6.2
16
18
5.3
11
50
13
5.4
6.8
7.5
2.8
5.1
32
<1
4.6
2.6
1.4
5.4
9.5
1.9
1.8
16
36
16
25
24
18
16
12
1.9
<1
2.9
<1
2.7
3.4
<1
<1
<1
1.5
<1
4.3
6.3
1.7
5
59
19
74
34
18
77
58
15
34
72
379
264
83
174
118
129
127
46
173
83
47
194
150
40
92
173
326
260
172
75
129
130
117
5.3
25
10
7.5
29
22
4.8
16
28
123
34
55
99
57
34
288
14
72
26
21
81
57
47
40
38
181
81
104
287
88
77
42
6.3
10
3
1.9
17
5.4
7.1
5.7
12
27
9.6
23
56
34
19
1660
224
920
363
197
817
745
258
399
722
2300
1230
954
1510
733
700
N= number of samples pooled.
NA= not analyzed.
*138 plus 158.
Table 3. Concentrations of 2,3,7,8-substituted PCDDs/DFs (pg g–1, w.w.) in fishes and birds from Italy.
PCDD congeners
Species
Tissue
2378
12378
Tuna
Tuna
Tuna
Tuna
Swordfish
Swordfish
Swordfish
Cormorant
Cormorant
Cormorant
Swallow
Swallow
Swallow
Swallow
Liver
Muscle
Muscle
Fat
Muscle
Muscle
Liver
Liver
Liver
Liver
Liver
Liver
Muscle
Muscle
<2
<1
<3
< 40
<1
<3
< 10
< 15
<3
< 10
< 10
< 10
1.41
1.81
<2
<1
<1
< 20
<4
<2
< 10
< 75
<5
5.56
5.77
< 10
2.62
2.36
PCDF congeners
123478 123678 123789 1234678 OCDD
2378
< 10
<2
<3
< 15
<6
< 10
< 20
< 10
<8
<3
< 0.01
< 15
<3
<3
<6
<2
<3
< 18
<5
<6
< 20
<4
<8
<3
< 12
<2
13.1
<3
< 10
<3
<4
< 25
<6
< 10
< 20
< 10
<8
5.07
12.6
9.37
<3
5.7
< 10
<2
<3
< 25
<2
< 10
< 20
< 10
<8
<3
< 13
< 15
<3
<3
<5
<3
<3
< 10
< 10
< 10
< 30
<5
< 30
< 10
< 50
<6
<8
< 10
< 50
<2
<2
<7
<4
<4
< 30
<2
< 10
<6
< 25
<3
<6
<5
12378 23478 123478 123678 123789 234678 1234678 1234789 OCDF
NA
<2
<5
< 10
<4
<6
< 20
<2
<3
<2
9.11
<1
4.48
<5
NA
<2
<6
19
<4
<6
< 20
< 10
<3
7.7
< 12
<2
10.4
15
NA
3.21
<2
19.8
<5
<5
< 10
<4
< 10
<5
< 15
<6
<4
<4
NA
< 1.5
<2
<5
<4
<5
< 60
6.36
< 10
<5
< 15
<6
<3
<4
NA
<2
< 10
<5
<4
<5
< 10
<4
< 10
<5
< 15
<6
<4
<3
NA
<3
<2
< 10
<4
<5
< 10
<4
< 10
<6
< 15
<6
<4
<3
<6
<4
<4
< 12
< 12
< 10
< 25
<6
< 30
< 14
< 40
< 20
<4
< 10
<6
<3
<4
< 25
< 14
<8
< 25
<8
< 30
< 12
< 40
< 15
<4
< 20
< 10
<2
<3
<5
<3
<6
< 20
<4
< 16
<8
< 25
<3
<6
<6
NA = not analyzed.
Ambio Vol. 31 No. 3, May 2002
© Royal Swedish Academy of Sciences 2002
http://www.ambio.kva.se
209
above the limits of detection (Table 3). To our knowledge, reports of organochlorine concentrations in swordfish are not available for comparison. This study provides baseline measurements
of organochlorines in swordfish for the first time.
Cormorants
Concentrations of total PCBs in livers of cormorants ranged between 722 and 2300 ng g–1, w.w. (Table 1). The measured concentrations of PCBs in cormorant livers were comparable to
those reported in Germany (2400 ng g–1, w.w.) during 1985/86
(6). However, concentrations of total PCBs in cormorant livers
from Italy were less than those reported from Lake Biwa, Japan
(6800 ng g–1, w.w.) (20). Hexa-CB congener 153 accounted for
20% of the total PCB concentrations followed by congeners 138
(16%) and 180 (7%). Concentrations of p,p’-DDE in cormorant
livers ranged from 144 to 190 ng g–1, w.w. (mean: 166 ng g–1,
w.w.). Concentrations of PCNs in cormorant livers ranged from
130 to 795 pg g–1, w.w. (mean: 424 pg g–1, w.w.). Mean PCN
concentrations in cormorant livers were 7-times greater than
those found in the livers of tuna and swordfish. Estimated concentration of total PCNs in livers of cormorants collected from
the Baltic Sea was 14␣ 000 pg g–1, w.w. (21). Concentrations of
total PCNs measured in cormorant livers from Cabras lagoon in
the Sardinian Sea were approximately 30-fold less than those
reported in Baltic Sea cormorants. CN congeners 66/67, 42
(1,3,5,7-TeCN), 61 and 52/60 accounted for 90% of the total
PCN concentrations in cormorant livers. As mentioned earlier,
CN congeners 66/67, 61 and 52/60 were also abundant in bluefin
tuna livers. These congeners have been shown to be strongly
bioaccumulative in wildlife (21). PCDD congeners, 1,2,3,7,8PeCDD and 1,2,3,6,7,8-HxCDD and PCDF congeners 2,3,4,7,8PeCDF and 1,2,3,6,7,8-HxCDF were detected in livers of certain individual cormorants.
Barn Swallows
Swallows, particularly, tree swallows, are being widely used as
indicators of local contamination because they feed near their
nest of emergent aquatic insects (5, 22, 23). Barn swallows are
similar to tree swallows in their feeding habits and migratory
behavior. Barn swallows collected from agricultural areas near
Milan contained remarkable concentrations of PCBs. Mean concentrations of PCBs in liver and muscle of barn swallows were
1230 and 716 ng g–1, w.w., respectively (n = 2). Profiles of relative concentrations of PCB congeners in swallows were similar
Table 4. Estimated concentrations
(pg g–1, w.w.) of total TEQs*
in fishes and birds from Italy.
Species
Tissue
Tunafish
Tunafish
Tunafish
Tunafish
Tunafish
Tunafish
Swordfish
Swordfish
Swordfish
Cormorant
Cormorant
Cormorant
Swallow
Swallow
Swallow
Swallow
Liver
Liver
Liver
Muscle
Muscle
Fat
Liver
Muscle
Muscle
Liver
Liver
Liver
Liver
Liver
Muscle
Muscle
Toxic Equivalents
To our knowledge, no previous studies have reported on the occurrence of PCNs in biota from the Mediterranean Sea. The results of this study permitted the analysis of the relative contribution of PCNs to total TEQs (sum of TEQs of coplanar PCBs,
PCDDs/DFs and PCNs). All PCN congeners are planar and several of them exhibit AhR mediated cytochrome P450 induction,
analogous to TCDD (8, 9). Toxic equivalency factors (TEFs) or
relative potencies reported for several PCN congeners based on
in vitro bioassays using H4IIE rat hepatoma cells were used for
calculating TEQs (8, 9, 24). For comparison of TEQs contributed by PCNs, PCBs, PCDDs, and PCDFs, it would be appropriate to use TEFs derived using similar bioassays. For comparison of TEQs contributed by PCNs (PCN-TEQs) with those contributed by PCBs (PCB-TEQs), PCDDs (PCDD-TEQs) and
PCDFs (PCDF-TEQs), concentrations of 2,3,7,8-substituted congeners of PCDD and PCDF and non- and mono-ortho-substituted PCBs were multiplied by their corresponding TEFs derived
from H4IIE bioassays (7). Di-ortho PCBs were not included in
PCB-TEQ estimation.
It should be emphasized that the estimation of TEQs is for
the examination of relative contribution of PCNs, PCBs and
PCDDs/DFs to total TEQ concentrations and not for risk assessment, which would require species-specific TEFs. Calculated
concentrations of total TEQs (sum of TEQs of PCBs, PCNs and
PCDDs/DFs) in the tissues of tuna ranged from 0.99 to 28 pg
g–1, w.w. (Table 4). Total TEQs in swordfish tissues were in the
range of 1.47 to 3.55 pg g–1, w.w.. Total TEQs in swallow tissues were greater (14.1–19.7 pg g–1, w.w.) than those estimated
for cormorant livers (5.75–11.9 pg g–1, w.w.). Non- and monoortho PCBs were the major contributors to total TEQ concentrations in fishes (Fig. 2). In particular, non-ortho coplanar PCB
Figure 2. Relative contribution (%) of PCBs, PCNs and PCDDs/DFs to total TEQ
concentrations in tissues of tuna, swordfish, cormorants and swallows.
PCBs
PCNs
Total TEQs
6.65
10.1
6.76
2.07
0.99
28.5
3.55
1.47
1.66
9.54
11.9
5.75
18.7
14.1
19.7
18.8
* Sum of TEQs of PCBs, PCNs and
PCDDs/DFs.
* For those congeners below the limits of
detection, detection limits were used to
calculate the TEQs.
210
to those observed for cormorants with PCB congener 153 accounting for the greatest proportion of total PCB concentrations
followed in decreasing order by CB congener 138 ≥ congener
180. Concentrations of p,p’-DDE in the liver and muscle of swallows were 95 and 75 ng g–1, w.w., respectively (Table 1). PCNs
were also found in swallows at concentrations ranging from 116
to 215 pg g–1, w.w.. PCN congeners 52/60 and 66/67 were the
major congeners in swallow tissues. Among PCDDs/DFs,
2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 1,2,3,6,7,8-HxCDD, 2,3,7,8TeCDF, 1,2,3,7,8-PeCDF and 2,3,4,7,8-PeCDF were detected in
barn swallows (Table 3).
Tuna liver
PCDDs/DFs
Tuna muscle
Tuna fat
Swordfish liver
Swordfish muscle
Cormorant liver
Swallow liver
Swallow muscle
0
20
© Royal Swedish Academy of Sciences 2002
http://www.ambio.kva.se
40
60
80
Contribution (%)
100
Ambio Vol. 31 No. 3, May 2002
congener 126 accounted for 80 to 90% of the total TEQs in
fishes. The contribution of this congener to total TEQs was relatively less in birds accounting for 52 to 76% of the total TEQs.
In the livers of cormorants and muscle tissues of swallows,
PCDDs/DFs contributed up to 80 and 45%, respectively, of the
total TEQs. PCDF congeners 2,3,7,8-TeCDF and 2,3,4,7,8PeCDF accounted for 60% of the PCDD/DF-TEQs in swallow
muscle. In cormorant livers, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF
and 1,2,3,6,7,8-HxCDF accounted for 95% of the PCDD/DFTEQs. The contribution of PCNs to total TEQs in fishes and
birds from the Mediterranean Sea was less than 2%. The greatest PCN-TEQ concentration of 0.15 pg g–1 was 1.3% of the total TEQs calculated in the liver of a cormorant. In fishes, PCNs
accounted for up to 0.3% of the total TEQs. This is less than
what has been reported to occur in earlier studies in which PCNs
contributed up to 50% of the total TEQs in fishes from the Detroit River (25). PCN congeners 66/67 accounted for 0.3 to 13%
of the total TEQs in fishes from the Baltic Sea (26). Relatively
less contribution of PCNs to TEQs in Mediterranean fishes and
cormorants suggests less exposure in off-shore species analyzed
in this study. Although this calculation gives the relative importance of each organochlorine group to the total contribution of
dioxin-like effects, caution should be exercised in assessing the
risks since non-detects were assigned a concentration of zero for
estimating the TEQs. The limits of detection of certain PCDD/
DF congeners were high.
References and Notes
1. Corsolini, S., Focardi, S., Kannan, K., Borrell, A., Tanabe, S. and Tatsukawa, R. 1995.
Congener profile and toxicity assessment of polychlorinated biphenyls in dolphins, shark
and tuna collected from Italian coastal waters. Mar. Environ. Res. 40, 33–53.
2. Marsili, L. and Focardi, S. 1997. Chlorinated hydrocarbon (HCB, DDTs and PCBs)
levels in cetaceans stranded along the Italian coasts: An overview. Environ. Monit. Assess. 45, 129–180.
3. Reich, S., Jimenez, B., Marsili, L., Hernández, L.M., Schurig, V. and González, M.J.
1999. Congener specific determination and enantiomeric ratios of chiral polychlorinated
biphenyls in striped dolphins (Stenella coeruleoalba) from the Mediterranean Sea.
Environ. Sci. Technol. 33, 1787–1793.
4. Kannan, K., Blankenship, A.L., Jones, P.D. and Giesy, J.P. 2000. Toxicity reference
values for the toxic effects of polychlorinated biphenyls to aquatic mammals. Hum.
Ecol. Risk Assess. 6, 181–201.
5. Ankley, G.T., Niemi, G.J., Lodge, K.B., Harris, H.J., Beaver, D.L., Tillitt, D.E.,
Schwartz, T.R., Giesy, J.P., Jones, P.D. and Hagley, C. 1993. Uptake of planar
polychlorinated biphenyls and 2,3,7,8-substituted polychlorinated dibenzofurans and
dibenzo-p-dioxins by birds nesting in the lower Fox River and Green Bay, Wisconsin,
USA. Arch. Environ. Contam. Toxicol. 24, 332–344.
6. Scharenberg, W. 1991. Cormorants (Phalacrocorax carbo sinensis) as bioindicators
of polychlorinated biphenyls. Arch. Environ. Contam. Toxicol. 21, 536–540.
7. Giesy, J.P., Jude, D.J., Tillitt, D.E., Gale, R.W., Meadows, J.C., Zajieck, J.L., Peterman, P.H., Verbrugge, D.A., Sanderson, J.T., Schwartz, T.R. and Tuchman, M.L. 1997.
Polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in fishes from Saginaw Bay, Michigan. Environ.
Toxicol. Chem. 16, 713–724.
8. Villeneuve, D.L., Kannan, K., Khim, J.S., Falandysz, J., Blankenship, A.L. and Giesy,
J.P. 2000. Relative potencies of individual polychlorinated naphthalenes to induce dioxin-like responses in fish and mammalian in vitro bioassays. Arch. Environ. Contam.
Toxicol. 39, 273–281.
9. Blankenship, A., Kannan, K., Villalobos, S., Villeneuve, D.L., Falandysz, J., Imagawa,
T., Jakobsson, E. and Giesy, J.P. 2000. Relative potencies of individual polychlorinated
naphthalenes and Halowax mixtures to induce Ah receptor-mediated responses. Environ.
Sci.Technol. 34, 3153–3158.
10. Kannan, K., Hilscherova, K., Imagawa, T., Yamashita, N., Williams, L.L. and Giesy,
J.P. 2001. Polychlorinated naphthalenes, -biphenyls, -dibenzo-p-dioxins, and -dibenzofurans in double crested cormorants and herring gulls from Michigan waters of the Great
Lakes. Environ. Sci. Technol. 35, 441–447.
11. Khim, J.S., Villeneuve, D.L., Kannan, K., Hu, W.Y., Giesy, J.P., Kang, S.G., Song,
K.J. and Koh, C.H. 2000. Instrumental and bioanalytical measures of persistent
organochlorines in blue mussel (Mytilus edulis) from Korean coastal waters. Arch.
Environ. Contam. Toxicol. 39, 360–368.
12. Ballschmiter, K. and Zell, M. 1980. Analysis of polychlorinated biphenyls (PCB) by
glass capillary gas chromatography. Fres. Z. Anal. Chem. 302, 20–31.
13. Kannan, K., Imagawa, T., Blankenship, A.L. and Giesy, J.P. 1998. Isomer-specific
analysis and toxic evaluation of polychlorinated naphthalenes in soil, sediment and biota
collected near the site of a former chlor-alkali plant. Environ. Sci. Technol. 32, 2507–
2514.
14. Impellizzeri, G., Tringali, C., Chillemi, R. and Piattelli, M. 1982. Observations on the
levels of DDTs and PCBs in the central Mediterranean. Sci. Total Environ. 25, 169–
179.
15. Frame, G.M., Wagner, R.E., Carnahan, J.C., Brown, J.F. Jr., May, R.J., Smullen, L.A.
and Bedard, D.L. 1996. Comprehensive, quantitative, congener-specific analysis of eight
Aroclors and complete PCB congener assignments on DB-1 capillary GC columns.
Chemosphere 33, 603–623.
16. Boon, J.P., Arnheim, E.V., Jansen, S., Kannan, N., Petrick, G., Schulz, D., Duinker,
J.C., Reijnders, P.J.H. and Goksøyr, A. 1992. The toxicokinetics of PCBs in marine
mammals with special reference to possible interactions of individual congeners with
the cytochrome P450-dependent monoxygenase system: an overview. In: Peristent Pollutants in Marine Ecosystems. Walker, C.H. and Livingstone, D.R. (eds). Pergamon
Press, New York, pp. 119–159.
17. Sinkkonen, S. and Paasivirta, J. 2000. Polychlorinated organic compounds in the Arctic cod liver: trends and profiles. Chemosphere 40, 619–626.
18. Järnberg, U., Asplund, L., de Wit, C., Egebäck, A-L., Wideqvist, U. and Jakobsson,
E. 1997. Distribution of polychlorinated naphthalene congeners in environmental and
source-related samples. Arch. Environ. Contam. Toxicol. 32, 232–245.
19. Jimenez, B., Gonzalez, M.J., Jimenez, O., Reich, S., Eljarrat, E. and Rivera, J. 2000.
Evaluation of 2,3,7,8 specific congener and toxic potency of persistent polychlorinated
dibenzo-p-dioxins and polychlorinated dibenzofurans in cetaceans from the Mediterranean Sea, Italy. Environ. Sci. Technol. 34, 756–763.
20. Guruge, K.S., Tanabe, S., Fukuda, M., Yamagishi, S. and Tatsukawa, R. 1997. Accumulation pattern of persistent organochlorine residues in common cormorants
(Phalacrocorax carbo) from Japan. Mar. Pollut. Bull. 34, 186–193.
21. Falandysz, J. 1998. Polychlorinated naphthalenes: an environmental update. Environ.
Pollut. 101, 77–90.
22. Froese, K.L., Verbrugge, D.A., Ankley, G.T., Niemi, G.J., Larsen, C.P. and Giesy, J.P.
1998. Bioaccumulation of polychlorinated biphenyls from sediments to aquatic insects
and tree swallow eggs and nestlings in Saginaw Bay, Michigan, USA. Environ. Toxicol.
Chem. 17, 484–492.
Ambio Vol. 31 No. 3, May 2002
23. Harris, M.L. and Elliott, J.E. 2000. Reproductive success and chlorinated hydrocarbon
contamination in tree swallows (Tachycineta bicolor) nesting along rivers receiving
pulp and paper mill effluent discharges. Environ. Pollut. 110, 307–320.
24. Hanberg, A., Ståhlberg, M., Georgellis, A., de Wit, C. and Ahlborg, U.G. 1991. Swedish
dioxin survey: evaluation of H4IIE bioassay for screening environmental samples for
dioxin-like enzyme induction. Pharmacol. Toxicol. 69, 442–449.
25. Kannan, K., Yamashita, N., Imagawa, T., Decoen, W., Khim, J.S., Day, R.M., Summer, C.L. and Giesy, J.P. 2000. Polychlorinated naphthalenes and polychlorinated
biphenyls in fishes from Michigan waters including the Great Lakes. Environ. Sci.
Technol. 34, 566–572.
26. Järnberg, U., Asplund, L., de Wit, C., Grafström, A-K., Haglund, P., Jansson, B., Lexén,
K., Strandell, M., Olsson, M. and Jonsson, B. 1993. Polychlorinated biphenyls and
polychlorinated naphthalenes in Swedish sediment and biota: Levels, patterns and time
trends. Environ. Sci. Technol. 27, 1364–1374.
27. We thank Istituto Centrale per la Ricerca Scientifica e Tecnologica Applicata al Mare
(ICRAM) for providing samples of tuna fish and sword fish; Prof. Claudio Leonzio
(University of Siena) and Istituto Zooprofilattico Sperimentale per la Sardegna,
Dipartimento Igiene degli Allevamenti e delle Produzioni Zootecniche for providing
tissues of cormorants. We thank Prof. Nicola Saino, University of Milano for providing tissues of barn swallows.
28. First submitted 19 March 2001. Accepted for publication after revision August 2001.
Kurunthachalam Kannan, PhD, is a Visiting Associate
Professor at National Food Safety and Toxicology Center in
Michigan State University, East Lansing, Michigan, USA.
His address: National Food Safety and Toxicology Center,
Department of Zoology, Institute for Environmental
Toxicology, Michigan State University, East Lansing,
MI 48824, USA.
E-mail: kuruntha@msu.edu
Simonetta Corsolini, PhD, is a research scientist at
Department of Environmental Biology, University of Siena,
Italy. Her address: Dipartimento di Scienze Ambientali,
Università di Siena, I-53100 Siena, Italy.
E-mail: corsolini@unisi.it
Takashi Imagawa, PhD, is a senior research scientist at
National Institute for Resources and Environment, Tsukuba,
Japan. His address: National Institute for Resources and
Environment, 16-3 Onogawa, Tsukuba, Ibaraki 305, Japan.
Silvano Focardi, PhD, is a professor at Department of
Environmental Biology, University of Siena, Italy. His
address: Dipartimento di Scienze Ambientali, Università di
Siena, I-53100 Siena, Italy.
John P. Giesy, PhD, is a distinguished professor of
Department of Zoology, National Food Safety and
Toxicology Center and Institute for Environmental
Toxicology at Michigan State University. His address:
National Food Safety and Toxicology Center, Department of
Zoology, Institute for Environmental Toxicology, Michigan
State University, East Lansing, MI 48824, USA.
E-mail: jgiesy@aol.com
The research interests of the authors include understanding
of environmental distribution, dynamics, fate and effects of
trace organic pollutants.
© Royal Swedish Academy of Sciences 2002
http://www.ambio.kva.se
211