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Influence of metropolitan waste on the concentration of chlorinated hydrocarbons and metals in striped mullet
Marine PollutionBulletin and that as such they must be exploited for the benefit of all. However such exploitation cannot and must not be greater than the maximum sustainable yield of a stock. The
present trend of increase in the use of monofilament gillnets makes this no longer a mere possibility, but probable, if not inevitable, in the very near future.
MarinePollution Bulletin, Vol. 13, No. 8, pp. 266-269,1982
0025-326X/82/080266434 $03.00/0
©
Printed inGreat Britain
1982Pergamon Press Ltd.
2 S S28 Influence of Metropolitan Waste on the Concentration of Chlorinated Hydrocarbons and Metals in Striped Mullet F. VOUTSINOU-TALIADOURI and J. SATSMADJIS
Institute of Oceanographic and Fisheries Research, Agios Kosmas, A them, Greece Striped mullet (Mullus barbatus), taken from five areas in the Saronikos Gulf (Greece), were examined for length, weight, hexane extract, chlorinated hydrocarbons (PCBs, DDE, DDT, DDD, BHCs, heptachlor epoxide, dieldrin, endrin) and metals (Fe, Zn, Cu, Pb, Mn, Ni, Cd, Cr, Co). The results established that the waste, either liquid or solid, from the Greater Athens metropolitan area had only a slight influence on the concentration of the metals, but a considerable effect on that of the organochlorine residues. Thus, the samples from the most polluted area, in the vicinity of Piraens harbour, contained on the average 15 limes as much PCBs and DDTs as those from the cleanest area, while the metals levels were raised by just 50%. Since 1951, the population of the Greater Athens metropolitan area has risen from 1 400 000 to 3 500 000 inhabitants. This growth continues, though more slowly, causing acute problems. One of them is marine pollution, induced by domestic waste or industrial effluent at various points, but especially at a location, near Piraeus harbour, where the central sewage pipe discharges untreated water into the sea. In view of the steadily deteriorating situation, efforts have constantly been made to estimate the damage inflicted upon the environment. As part of such a monitoring programme, specimens of Mullus barbatus (striped mullet) have been collected in the Saronikos Gulf since 1975. This fish was chosen because, besides its commercial interest, it feeds on organisms living on the bottom of the sea, where pollutants, if present, accumulate, and is found throughout the Mediterranean Sea, thus enabling comparisons over the whole extent of this part of the world. In this study, the investigated microconstituents were various metals, polychlorinated biphenyls (PCBs) and the common chlorinated pesticides. 266
Methodology For the purpose of this work, five sampling areas were selected in the Saronikos Gulf. Area A (see Fig. 1) comprises the site of the chief sewage terminal, as well as, close by and just outside Piraeus harbour proper, the place where, over many years, a large fertilizer factory has been dumping considerable amounts of metal-containing sludge. Note that, to the north of it, the eastern section of Elefsis Bay, with its great industrial and shipping activity, is in an even worse condition. Area B adjoins area A to the south, but is not directly exposed to intense pollution. Area C, a long way further to the south and on the outskirts of the Gulf, lies in the main path of the outgoing stream. On the other hand, areas D and E, owing to the
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Fig. 1 Study area in the Saronikos Gulf.
Volume 13/Number 8/August 1982 TABLE 1 Separation of the organochlorines on the silica gel column. Quantities % in each fraction. Hexane fractions
20o/0 Ether fr.
Constituent
2.5-5 m!
5-6 ml
6-9 ml
9-14 ml
Aldrin PCBs p,p DDE Heptachlor p,p-DDT
76 73 64 29
15 21 26 45 15
7 5 8 22 74
2 1 2 4 11 70 17
p,p-DDD crBHC Lindane Hept. epoxide Dieldrin Endrin
14-24 ml
24-34 ml
27 81 76 79 81 73
3 2 24 21 19 27
predominant currents, are sheltered to some extent from the major sources of pollution. Sampling was carried out by trawler, usually four times a year, to include every season. Each specimen had its weight and fork length measured. The fleshy parts were carved off and mixed with those of, on the average, five other fishes. These composite samples, except for the first eleven, were lyophilized and stored in a deep freeze until analysed. For the determination of chlorinated hydrocarbons, the technique carried out was a modified version of that described by Holden & Marsden (1969). It comprises the following steps: (1) Hexane extraction of 5 g oflyophilized sample. (2) Clean-up of an aliquot (5%) of the extract, evaporated to 0.3-0.5 ml, on a column (6 mm i.d., 130 mm packing length) containing 4 g of alumina (4 h at 800°C, 5 % water), collecting the first 20 ml of hexane eluate.
(3) Separation ofthis eluate, concentrated to0.3-0.5 ml, on a silica gel (60-120 mesh, 3 h at 180 °, 16% water) column (4 mm i.d., 580 mm packing length), previously rinsed first with 20 ml 20% ether in hexane, then with 20 ml hexane and thoroughly wetted with it. At the start, the eluent is hexane; it is replaced with 20% ether in hexane after the first 11 ml have been collected. Table 1 indicates the relative amounts, in percentages of the total, of each of the components in the various fractions. This separation, though incomplete, reduces greatly interference (mostly from PCBs) and the danger of identification errors. (4) Analysis of each fraction by injection of a suitable volume (2-8 gl) into a gas chromatograph having nitrogen as carrier gas and equipped with a glass column (6 ft × ¼in., 3% OV-1 on chromosorb W-HP, 200°C) and a Ni-63 electron capture detector (heated at 260°C). The great reliability of this method has been ascertained in intercalibration exercises. The coefficient of variation of duplicates is of the order of 10 for the DDTs, 20 for the PCBs and 15 to 40 for the other constituents. It depends not only on the concentration level, but also on the presence of interfering compounds. To analyse the metals, the samples were digested in conc. HNO3 inside closed Teflon tubes, then processed on a Perkin-Elmer 305 B atomic absorption spectrophotometer equipped with a deuterium arc background corrector. Except in the case of Zn and Fe, requiring only the flame, because of their high concentrations, the graphite furnace was used, according to the procedure described by Satsmadj is & Voutsinou-Taliadouri (1981). lntercalibration exer.sises proved the accuracy of the method. The coefficient of variation of duplicate samples was 2-4 for Fe and Zn, 6-10 for Cu, Pb, Mn and 20-40 for Ni, Cd, Cr, Co.
TABLE 2
Chlorinated hydrocarbons. Area
Parameter
(No. sampl.)
Length (mm)
Weight (g)
Extract (%)
PCBs (ppb)
DDE (ppb)
DDT (ppb)
A/E
135 145 125 7 1.07
44 58 35 8 1.29
4.24 7.40 2.80 1.70 2.42
460 1200 170 380 17.56
72 151 39 35 8.89
B (14)
Mean High Low o B/E
147 205 124 34 1.17
58 139 29 62 1.71
2.92 5.30 1.16 1.84 1.67
176 340 63 87 6.72
29.7 48 8.6 12 3.67
20.3 41 5.3 10 4.06
C (18)
Mean High Low o C/E
142 165 118 16 1.13
46 66 26 14 1.35
2.41 5.80 0.86 1.50 1.38
70 124 16 37 2.67
31.7 67 12.5 20 3.91
D (17)
Mean High Low o D/E
137 155 129 9 1.09
44 68 33 16 1.29
3.59 6.20 1.33 1.65 2.05
36.5 90 3.8 36 1.39
E
Mean High Low o
126 145 107 11
34 56 21 11
1.75 3.79 0,79 1,05
26.2 53 13,9 13.1
A (13)
Mean High Low O
(12)
78 118 48 24 15.6
DDD (ppb) 66 145 26 52 27,5
YDDTs (ppb)
BHCs (ppb)
Hept. epox.
(ppb)
Dieldrin Endrin (ppb) (ppb)
216 400 125 105 13.94
5.6 8.2 3.8 1.4 3.73
0.3 0.5 0.2 0.2 1.5
17 50 0.4 17 34
2.3 3.5 0.9 1.5 11.5
12,4 20 5 8 5,17
62.4 102 20.1 24 4.03
5.6 10 1 3.5 3.73
0.3 0.6 0.1 0.2 1.5
2.4 4.7 0.1 2.2 4.8
1.5 2 0.5 0.8 7,5
26.6 51 9.7 12 5.32
4.1 11 0.2 4 1.71
62.4 122 28.9 34 4.03
2.5 5.5 0.2 2 1.67
0.5 1.2 0.1 0.5 2.5
1 1.8 0.1 0.6 2
1.1 2,3 0.1 0.9 5.5
14.2 35 4 14 1.75
9.7 18 3.5 8 1.94
4.3 7.7 0.6 3.3 1.79
28.2 58 8.4 23 1.82
4.6 9.9 0.4 4.8 3.07
0.3 0.7 0.0 0.1 1.5
1.1 3.1 0.0 1.4 2.2
0.9 2.2 0.3 0.9 4.5
8.1 20.5 2,3 5,9
5 12 1 3.5
2.4 5.2 0.3 1.9
15.5 37.7 3.6 10.8
1.5 2.5 0.3 0.8
0.2 0.5 0.1 0.2
0.5 0.9 0.1 0.3
0.2 0.6 0.0 0.2
267
Marine Pollution Bulletin TABLE 3 Metals. Area (No. sampl.)
Parameter
Fe (ppb)
Zn (ppb)
Cu (ppb)
Pb (ppb)
Mn (ppb)
Ni (ppb)
Cd (ppb)
Cr (ppb)
Co (ppb)
A (13)
Mean High Low o A/E
9600 13000 5500 3280 1.57
5800 7000 4100 1430 1.21
913 1360 530 315 1.29
420 500 240 185 1.69
357 440 260 86 1.05
148 270 65 89 1.78
78 170 35 74 1.34
33 69 25 14 1.43
65 80 40 28 1.55
B (14)
Mean High Low o B/E
8240 11300 4600 3500 1.35
5200 6400 3900 970 1.08
826 1280 460 298 1.17
340 430 190 137 1.37
300 350 230 52 0.88
130 260 55 95 1.57
59 110 30 35 1.02
29 60 20 13 1.26
56 78 36 21 1.33
C C (19)
Mean High Low o C/E
7570 10500 4100 1810 1.24
4270 7100 3600 1280 0.89
790 1300 400 310 1.12
312 460 250 82 1.26
316 380 210 66 0.93
125 280 35 90 1.51
49 60 21 31 0.84
14 32 8 8 0.61
48 70 30 26 1.14
D (17)
Mean High Low o D/E
6670 10800 3200 2830 1.09
4900 6200 3200 920 1.02
720 1120 360 260 1.02
262 350 100 106 1.06
311 370 270 53 0.92
105 230 25 77 1.27
65 160 15 39 1.12
13 30 8 10 0.57
40 59 26 13 0.95
E (12)
Mean High Low o
4830 6600 3100 1200
708 1130 400 267
248 340 80 109
339 450 240 83
83 190 18 85
58 150 15 57
23 70 10 17
42 60 30 15
6100 9600 2800 2080
Results and Discussion Tables 2 and 3 indicate, for each parameter and area, the average of the results of all the analyses (mean), their m a x i m u m (high) and m i n i m u m (low), the standard deviation and the ratio of the mean in that given area to the mean in area E (A/E, B/E, etc.). Table 4 gives for each constituent the ratio, q, of the difference between the mean in area A and that in the area shown to the standard deviation of this difference: q=(~J-~2) [(o~/nl)+(o~/n2)] -v2, with ~1, ol, nl, respectively, the mean, standard deviation and number of
TABLE 4 Significance of the differences between areas. Area B q*
Area C q*
Area D q*
Area E q*
Extract PCBs p , p - DDE p,p - DDT p,p-DDD YDDTs BHCs Dieldrin Endrin
1.94 2.63 4.14 8.04 3.68 5.15 0.00 3.07 1.71
3.11 3.69 3.73 7.11 4.28 5.09 5.08 3.39 2.57
1.05 4.00 5.62 9.85 4.27 6.33 0.81 3.36 2.98
4.44 4.11 6.48 10.84 4.41 6.85 9.08 3.50 5.00
Fe Zn Cu Pb Mn Ni Cd Cr Co
1.04 1.27 0.74 1.27 2.06 0.51 0.84 0.77 0.94
2.02 3.07 1.08 1.97 1.44 0.71 1.33 4.40 1.72
2.57 1.98 1.79 2.75 1.70 1.39 0.58 4.37 2.98
3.21 1.84 1.76 2.86 0.53 1.87 0.76 1.60 2.59
Constituent
*Ratio, q, of the difference between the mean in area A and that in the area shown to the standard deviation of this difference. q 1 1.5 2 2.5 3 Probability (%) 84.13 93.32 97.73 99.38 99.87
268
samples in area A and ~2, 02, n2 those in the area considered.
Chlorinated hydrocarbons Table 4 proves that the main constituents (PCBs, DDE, DDT, DDD) present concentrations in area A most significantly different from those in the other areas. The same ratio q is, for PCBs and ZDDTs, respectively 4.27, 0.00 between B and C, 2.71, 3.50 between C and D and 1.08, 4.11 between D and E. This indicates that, except between B and C for 5-DDTs and D and E for PCBs, all areas undoubtedly differ from one another. The evidence is not quite as strong in the instance of the hexane extract, BHCs, dieldrin and endrin. The concentrations of heptachlor epoxide are too low and uncertain to be worth comparing. The above statistical study demonstrates the powerful influence of the main sewage outfall. As can be seen in Table 2 from the ratios A/E, B/E, etc., the concentrations of the major chlorinated hydrocarbons (PCBs, DDE, DDT, DDD) fall dramatically from one area to the next one in the sequence A, B, C, D and E, more particularly from A to B. This shows that Mullus barbatus readily takes in the compounds, either through the gills or from food at the bottom of the sea. The rate of decrease depends on the constituent. PCBs, used only in industries, must originate almost exclusively from the central sewage. Hence, their levels reflect truly the effects of distance and time: dilution, evaporation and, if any, decomposition. These levels drop very sharply from A to B (2.6 times), from B to C (2.5 times) and from C to D (1.9 times). On the contrary, the pesticides DDE, DDT and DDD could proceed also from the countryside. Despite that, the values of DDD undergo changes even more pronounced than those of the PCBs: 5.3 times fall from A to B and 3.0 from B to C. On the other hand,
Volume 13/Number 8/August 1982
DDT and DDE behave erratically. Thus, their concentrations diminish respectively 3.8 and 2.4 times from A to B, do not change significantly from B to C, then decrease again 2.7 and 2.2 times from C to D. This suggests perhaps a greater resistance, especially of DDE, to degradation in the sea or within the fish, than DDD. Amongst the minor constituents (BHCs, heptachlor epoxide, dieldrin and endrin), only the last two follow to some extent the general trend. The lipids (hexane extract) seem to play a major part in the retention by Mullus barbatus of organochlorine residues. The individual analyses, not reported here, demonstrate that in areas A, B, C, D and E, the lipids are tied both to the PCBs (correlation coefficients, r, respectively 0.998, 0.888, 0.169, 0.832, 0.283) and EDDTs (r=0.992, 0.547, 0.335, 0.972, 0.172). They show also, though more loosely, a connection to the length in all areas A, B, C, D, E (r--0.70, 0.62, 0.11, 0.67, 0.54); hence, contamination tends to increase with the size of the fish. The above facts are easy to explain. The lipophilic chlorinated hydrocarbons get into the body mostly through food; the more food ingested, the larger the amount of the pollutants retained, but the more too the fat produced. Conversely, during fasting, the lipids are catabolized and it is reasonable to assume that part at least of the impurities they held disappear with them. Another feature of the major chlorinated hydrocarbons is the extreme scattering of their values in a given area, especially one relatively clean. Thus, in areas A, B, C, D, E, the means of the ratios h / l are respectively 4.7, 5.7, 18.3, 12.6, 10.5. This leads to the inference that Mullus barbatus does not always remain in the same vicinity, but, at times, travels a long way across the Saronikos Gulf. Fish heavily contaminated, migrating within, say, a few weeks to less foul waters would still contain high proportions of the chemicals, since the detoxification process is a slow one. Note that, except perhaps in the instance of a few specimens caught near the sewage outfall, the concentrations of the organochlorine residues stay well below the health hazard limits. They confirm previous work carried out in areas A, B, C, D, by Satsmadjis & Gabrielides (1979) whose data have been, for this reason, incorporated here. They compare also with those found in other polluted regions of the Mediterranean. Thus, the levels of YPCBs, YDDTs and BHCs in the muscle of Mullus barbatus reported by Fossato & Craboledda (1980), concerning various areas of the northern Adriatic Sea, are on the average lower than those listed in Table 1. On the contrary, the ZPCBs and ZDDTs figures quoted by Contardi et al. (1981) for the section of the Ligurian Sea close to Genoa are significantly higher, while those of the YBHCs are smaller. Metals
Table 4 establishes that area A often presents a significant difference from the other areas. Thus, in 20 cases out
of 36, q~> 1.50 (probability at least 93.3°/o) and, in 9 cases out of 36, q>~ 2.50 (probability at least 99.4°7o). However, Table 3 shows that the differences are not only small, but also, excepting area A, do not, as a rule, exhibit a clear trend. In brief, the site affects Fe, Ni, Cu, Co only very slightly, Zn, Cr, Cd to an even smaller extent and Mn not at all. Furthermore, the ratios of the extreme values are not excessive. Thus, the means of h / l for the major constituents (Fe, Zn, Cu, Pb, Mn) in areas A, B, C, D, E are respectively 2.1, 2.1, 2.3, 2.7, 2.9, while, for the remainder of the elements (Ni, Cd, Cr, Co), these means, as expected, are higher: 3.5, 3.4, 4.3, 6.5, 7.4. The impressively small differences between the levels of the metals in various parts of the Saronikos Gulf may have their explanation in the very swift decline of their concentrations in the sediments when getting away from the main sources of pollution, which are the sewage outfall and the fertilizer factory, both in area A (Voutsinou-Taliadouri, 1981). Probably for the same reason, Papadopoulou et al. (1980), working on samples of Mullus barbatus taken from the same region, concluded that the central sewage outfall did not seem to affect the As, Cu and V contents of the fish. Other authors elsewhere in the world made similar remarks. For example, Young et al. (1981) established that the muscle tissues of five popular benthic feeding sportfishes caught near the Los Angeles County municipal wastewater outfalls, analysed for Zn, Cu, Cd, Cr, Pb, Hg, Ni, Ag, exhibited levels not above those measured in island and coastal control specimens, with the possible exception of Zn and Cu.
The authors wish to thank Athanasia Goudjamani-Kyranaki and Eustathius Hadjigeorgiou for helping with the analyses and Basel Marouda-Lambropoulou for drawing the map.
Contardi, V., Zanicchi, G., Mazzone, D. & Magrocosma, B. (1980). Fluctuations saisonni~res de DPC, DDT et m6tabolites dans les organismes de lamer Ligure. In Ves Journ#es Etud. Pollutions, pp. 335-340. Cagliari, C.I.E.S.M. Fossato, V. U. & Craboledda, k. (1980). Chlorinated hydrocarbons in organisms from the Italian Coast of the Northern Adriatic Sea. In Ve~ Journ#esEtud. Pollutions, pp. 169-174. Cagliari, C.I.E.S.M. Holden, A. V. & Marsden, K. (1969). Single-stage clean-up of animal tissue extracts for organochlorine residue analysis. J. Chromat., 44, 481-492. Papadopoulou, C., Zafiropoulos, D. & Grimanis, A. P. (1980). Arsenic, copper and vanadium in Mullus barbatus and Parapenaeus long# rostris from the Saronikos Gulf, Greece. In Vet Journ~es Etud. Pollutions, pp. 419-422. Cagliari, C.I.E.S.M. Satsmadjis, J. & Gabrielides, G. P. (1979). Observations on the concentration levels of chlorinated hydrocarbons in a Mediterranean fish. Mar. Pollut. Bull., 10, 109-111. Satsmadjis, J. & Voutsinou-Taliadouri, F. (1981). Determination of trace metals at concentrations above the linear calibration range by electrothermal atomic absorption spectrometry. Analyt. Chim. Acta, 131, 83-90. Voutainou-Taliadouri, F. (1981). Metal pollution in the Saronikos Gulf. Mar. Pollut. Bull., 12, 163-168. Young, D. R., Moore, M. D., Jan, T.-K. & Eganhouse, R. P. (1981). Metals in seafood organisms near a large California municipal outfall. Mar. Pollut. Bull., 12, 134-138.
269
present trend of increase in the use of monofilament gillnets makes this no longer a mere possibility, but probable, if not inevitable, in the very near future.
MarinePollution Bulletin, Vol. 13, No. 8, pp. 266-269,1982
0025-326X/82/080266434 $03.00/0
©
Printed inGreat Britain
1982Pergamon Press Ltd.
2 S S28 Influence of Metropolitan Waste on the Concentration of Chlorinated Hydrocarbons and Metals in Striped Mullet F. VOUTSINOU-TALIADOURI and J. SATSMADJIS
Institute of Oceanographic and Fisheries Research, Agios Kosmas, A them, Greece Striped mullet (Mullus barbatus), taken from five areas in the Saronikos Gulf (Greece), were examined for length, weight, hexane extract, chlorinated hydrocarbons (PCBs, DDE, DDT, DDD, BHCs, heptachlor epoxide, dieldrin, endrin) and metals (Fe, Zn, Cu, Pb, Mn, Ni, Cd, Cr, Co). The results established that the waste, either liquid or solid, from the Greater Athens metropolitan area had only a slight influence on the concentration of the metals, but a considerable effect on that of the organochlorine residues. Thus, the samples from the most polluted area, in the vicinity of Piraens harbour, contained on the average 15 limes as much PCBs and DDTs as those from the cleanest area, while the metals levels were raised by just 50%. Since 1951, the population of the Greater Athens metropolitan area has risen from 1 400 000 to 3 500 000 inhabitants. This growth continues, though more slowly, causing acute problems. One of them is marine pollution, induced by domestic waste or industrial effluent at various points, but especially at a location, near Piraeus harbour, where the central sewage pipe discharges untreated water into the sea. In view of the steadily deteriorating situation, efforts have constantly been made to estimate the damage inflicted upon the environment. As part of such a monitoring programme, specimens of Mullus barbatus (striped mullet) have been collected in the Saronikos Gulf since 1975. This fish was chosen because, besides its commercial interest, it feeds on organisms living on the bottom of the sea, where pollutants, if present, accumulate, and is found throughout the Mediterranean Sea, thus enabling comparisons over the whole extent of this part of the world. In this study, the investigated microconstituents were various metals, polychlorinated biphenyls (PCBs) and the common chlorinated pesticides. 266
Methodology For the purpose of this work, five sampling areas were selected in the Saronikos Gulf. Area A (see Fig. 1) comprises the site of the chief sewage terminal, as well as, close by and just outside Piraeus harbour proper, the place where, over many years, a large fertilizer factory has been dumping considerable amounts of metal-containing sludge. Note that, to the north of it, the eastern section of Elefsis Bay, with its great industrial and shipping activity, is in an even worse condition. Area B adjoins area A to the south, but is not directly exposed to intense pollution. Area C, a long way further to the south and on the outskirts of the Gulf, lies in the main path of the outgoing stream. On the other hand, areas D and E, owing to the
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Fig. 1 Study area in the Saronikos Gulf.
Volume 13/Number 8/August 1982 TABLE 1 Separation of the organochlorines on the silica gel column. Quantities % in each fraction. Hexane fractions
20o/0 Ether fr.
Constituent
2.5-5 m!
5-6 ml
6-9 ml
9-14 ml
Aldrin PCBs p,p DDE Heptachlor p,p-DDT
76 73 64 29
15 21 26 45 15
7 5 8 22 74
2 1 2 4 11 70 17
p,p-DDD crBHC Lindane Hept. epoxide Dieldrin Endrin
14-24 ml
24-34 ml
27 81 76 79 81 73
3 2 24 21 19 27
predominant currents, are sheltered to some extent from the major sources of pollution. Sampling was carried out by trawler, usually four times a year, to include every season. Each specimen had its weight and fork length measured. The fleshy parts were carved off and mixed with those of, on the average, five other fishes. These composite samples, except for the first eleven, were lyophilized and stored in a deep freeze until analysed. For the determination of chlorinated hydrocarbons, the technique carried out was a modified version of that described by Holden & Marsden (1969). It comprises the following steps: (1) Hexane extraction of 5 g oflyophilized sample. (2) Clean-up of an aliquot (5%) of the extract, evaporated to 0.3-0.5 ml, on a column (6 mm i.d., 130 mm packing length) containing 4 g of alumina (4 h at 800°C, 5 % water), collecting the first 20 ml of hexane eluate.
(3) Separation ofthis eluate, concentrated to0.3-0.5 ml, on a silica gel (60-120 mesh, 3 h at 180 °, 16% water) column (4 mm i.d., 580 mm packing length), previously rinsed first with 20 ml 20% ether in hexane, then with 20 ml hexane and thoroughly wetted with it. At the start, the eluent is hexane; it is replaced with 20% ether in hexane after the first 11 ml have been collected. Table 1 indicates the relative amounts, in percentages of the total, of each of the components in the various fractions. This separation, though incomplete, reduces greatly interference (mostly from PCBs) and the danger of identification errors. (4) Analysis of each fraction by injection of a suitable volume (2-8 gl) into a gas chromatograph having nitrogen as carrier gas and equipped with a glass column (6 ft × ¼in., 3% OV-1 on chromosorb W-HP, 200°C) and a Ni-63 electron capture detector (heated at 260°C). The great reliability of this method has been ascertained in intercalibration exercises. The coefficient of variation of duplicates is of the order of 10 for the DDTs, 20 for the PCBs and 15 to 40 for the other constituents. It depends not only on the concentration level, but also on the presence of interfering compounds. To analyse the metals, the samples were digested in conc. HNO3 inside closed Teflon tubes, then processed on a Perkin-Elmer 305 B atomic absorption spectrophotometer equipped with a deuterium arc background corrector. Except in the case of Zn and Fe, requiring only the flame, because of their high concentrations, the graphite furnace was used, according to the procedure described by Satsmadj is & Voutsinou-Taliadouri (1981). lntercalibration exer.sises proved the accuracy of the method. The coefficient of variation of duplicate samples was 2-4 for Fe and Zn, 6-10 for Cu, Pb, Mn and 20-40 for Ni, Cd, Cr, Co.
TABLE 2
Chlorinated hydrocarbons. Area
Parameter
(No. sampl.)
Length (mm)
Weight (g)
Extract (%)
PCBs (ppb)
DDE (ppb)
DDT (ppb)
A/E
135 145 125 7 1.07
44 58 35 8 1.29
4.24 7.40 2.80 1.70 2.42
460 1200 170 380 17.56
72 151 39 35 8.89
B (14)
Mean High Low o B/E
147 205 124 34 1.17
58 139 29 62 1.71
2.92 5.30 1.16 1.84 1.67
176 340 63 87 6.72
29.7 48 8.6 12 3.67
20.3 41 5.3 10 4.06
C (18)
Mean High Low o C/E
142 165 118 16 1.13
46 66 26 14 1.35
2.41 5.80 0.86 1.50 1.38
70 124 16 37 2.67
31.7 67 12.5 20 3.91
D (17)
Mean High Low o D/E
137 155 129 9 1.09
44 68 33 16 1.29
3.59 6.20 1.33 1.65 2.05
36.5 90 3.8 36 1.39
E
Mean High Low o
126 145 107 11
34 56 21 11
1.75 3.79 0,79 1,05
26.2 53 13,9 13.1
A (13)
Mean High Low O
(12)
78 118 48 24 15.6
DDD (ppb) 66 145 26 52 27,5
YDDTs (ppb)
BHCs (ppb)
Hept. epox.
(ppb)
Dieldrin Endrin (ppb) (ppb)
216 400 125 105 13.94
5.6 8.2 3.8 1.4 3.73
0.3 0.5 0.2 0.2 1.5
17 50 0.4 17 34
2.3 3.5 0.9 1.5 11.5
12,4 20 5 8 5,17
62.4 102 20.1 24 4.03
5.6 10 1 3.5 3.73
0.3 0.6 0.1 0.2 1.5
2.4 4.7 0.1 2.2 4.8
1.5 2 0.5 0.8 7,5
26.6 51 9.7 12 5.32
4.1 11 0.2 4 1.71
62.4 122 28.9 34 4.03
2.5 5.5 0.2 2 1.67
0.5 1.2 0.1 0.5 2.5
1 1.8 0.1 0.6 2
1.1 2,3 0.1 0.9 5.5
14.2 35 4 14 1.75
9.7 18 3.5 8 1.94
4.3 7.7 0.6 3.3 1.79
28.2 58 8.4 23 1.82
4.6 9.9 0.4 4.8 3.07
0.3 0.7 0.0 0.1 1.5
1.1 3.1 0.0 1.4 2.2
0.9 2.2 0.3 0.9 4.5
8.1 20.5 2,3 5,9
5 12 1 3.5
2.4 5.2 0.3 1.9
15.5 37.7 3.6 10.8
1.5 2.5 0.3 0.8
0.2 0.5 0.1 0.2
0.5 0.9 0.1 0.3
0.2 0.6 0.0 0.2
267
Marine Pollution Bulletin TABLE 3 Metals. Area (No. sampl.)
Parameter
Fe (ppb)
Zn (ppb)
Cu (ppb)
Pb (ppb)
Mn (ppb)
Ni (ppb)
Cd (ppb)
Cr (ppb)
Co (ppb)
A (13)
Mean High Low o A/E
9600 13000 5500 3280 1.57
5800 7000 4100 1430 1.21
913 1360 530 315 1.29
420 500 240 185 1.69
357 440 260 86 1.05
148 270 65 89 1.78
78 170 35 74 1.34
33 69 25 14 1.43
65 80 40 28 1.55
B (14)
Mean High Low o B/E
8240 11300 4600 3500 1.35
5200 6400 3900 970 1.08
826 1280 460 298 1.17
340 430 190 137 1.37
300 350 230 52 0.88
130 260 55 95 1.57
59 110 30 35 1.02
29 60 20 13 1.26
56 78 36 21 1.33
C C (19)
Mean High Low o C/E
7570 10500 4100 1810 1.24
4270 7100 3600 1280 0.89
790 1300 400 310 1.12
312 460 250 82 1.26
316 380 210 66 0.93
125 280 35 90 1.51
49 60 21 31 0.84
14 32 8 8 0.61
48 70 30 26 1.14
D (17)
Mean High Low o D/E
6670 10800 3200 2830 1.09
4900 6200 3200 920 1.02
720 1120 360 260 1.02
262 350 100 106 1.06
311 370 270 53 0.92
105 230 25 77 1.27
65 160 15 39 1.12
13 30 8 10 0.57
40 59 26 13 0.95
E (12)
Mean High Low o
4830 6600 3100 1200
708 1130 400 267
248 340 80 109
339 450 240 83
83 190 18 85
58 150 15 57
23 70 10 17
42 60 30 15
6100 9600 2800 2080
Results and Discussion Tables 2 and 3 indicate, for each parameter and area, the average of the results of all the analyses (mean), their m a x i m u m (high) and m i n i m u m (low), the standard deviation and the ratio of the mean in that given area to the mean in area E (A/E, B/E, etc.). Table 4 gives for each constituent the ratio, q, of the difference between the mean in area A and that in the area shown to the standard deviation of this difference: q=(~J-~2) [(o~/nl)+(o~/n2)] -v2, with ~1, ol, nl, respectively, the mean, standard deviation and number of
TABLE 4 Significance of the differences between areas. Area B q*
Area C q*
Area D q*
Area E q*
Extract PCBs p , p - DDE p,p - DDT p,p-DDD YDDTs BHCs Dieldrin Endrin
1.94 2.63 4.14 8.04 3.68 5.15 0.00 3.07 1.71
3.11 3.69 3.73 7.11 4.28 5.09 5.08 3.39 2.57
1.05 4.00 5.62 9.85 4.27 6.33 0.81 3.36 2.98
4.44 4.11 6.48 10.84 4.41 6.85 9.08 3.50 5.00
Fe Zn Cu Pb Mn Ni Cd Cr Co
1.04 1.27 0.74 1.27 2.06 0.51 0.84 0.77 0.94
2.02 3.07 1.08 1.97 1.44 0.71 1.33 4.40 1.72
2.57 1.98 1.79 2.75 1.70 1.39 0.58 4.37 2.98
3.21 1.84 1.76 2.86 0.53 1.87 0.76 1.60 2.59
Constituent
*Ratio, q, of the difference between the mean in area A and that in the area shown to the standard deviation of this difference. q 1 1.5 2 2.5 3 Probability (%) 84.13 93.32 97.73 99.38 99.87
268
samples in area A and ~2, 02, n2 those in the area considered.
Chlorinated hydrocarbons Table 4 proves that the main constituents (PCBs, DDE, DDT, DDD) present concentrations in area A most significantly different from those in the other areas. The same ratio q is, for PCBs and ZDDTs, respectively 4.27, 0.00 between B and C, 2.71, 3.50 between C and D and 1.08, 4.11 between D and E. This indicates that, except between B and C for 5-DDTs and D and E for PCBs, all areas undoubtedly differ from one another. The evidence is not quite as strong in the instance of the hexane extract, BHCs, dieldrin and endrin. The concentrations of heptachlor epoxide are too low and uncertain to be worth comparing. The above statistical study demonstrates the powerful influence of the main sewage outfall. As can be seen in Table 2 from the ratios A/E, B/E, etc., the concentrations of the major chlorinated hydrocarbons (PCBs, DDE, DDT, DDD) fall dramatically from one area to the next one in the sequence A, B, C, D and E, more particularly from A to B. This shows that Mullus barbatus readily takes in the compounds, either through the gills or from food at the bottom of the sea. The rate of decrease depends on the constituent. PCBs, used only in industries, must originate almost exclusively from the central sewage. Hence, their levels reflect truly the effects of distance and time: dilution, evaporation and, if any, decomposition. These levels drop very sharply from A to B (2.6 times), from B to C (2.5 times) and from C to D (1.9 times). On the contrary, the pesticides DDE, DDT and DDD could proceed also from the countryside. Despite that, the values of DDD undergo changes even more pronounced than those of the PCBs: 5.3 times fall from A to B and 3.0 from B to C. On the other hand,
Volume 13/Number 8/August 1982
DDT and DDE behave erratically. Thus, their concentrations diminish respectively 3.8 and 2.4 times from A to B, do not change significantly from B to C, then decrease again 2.7 and 2.2 times from C to D. This suggests perhaps a greater resistance, especially of DDE, to degradation in the sea or within the fish, than DDD. Amongst the minor constituents (BHCs, heptachlor epoxide, dieldrin and endrin), only the last two follow to some extent the general trend. The lipids (hexane extract) seem to play a major part in the retention by Mullus barbatus of organochlorine residues. The individual analyses, not reported here, demonstrate that in areas A, B, C, D and E, the lipids are tied both to the PCBs (correlation coefficients, r, respectively 0.998, 0.888, 0.169, 0.832, 0.283) and EDDTs (r=0.992, 0.547, 0.335, 0.972, 0.172). They show also, though more loosely, a connection to the length in all areas A, B, C, D, E (r--0.70, 0.62, 0.11, 0.67, 0.54); hence, contamination tends to increase with the size of the fish. The above facts are easy to explain. The lipophilic chlorinated hydrocarbons get into the body mostly through food; the more food ingested, the larger the amount of the pollutants retained, but the more too the fat produced. Conversely, during fasting, the lipids are catabolized and it is reasonable to assume that part at least of the impurities they held disappear with them. Another feature of the major chlorinated hydrocarbons is the extreme scattering of their values in a given area, especially one relatively clean. Thus, in areas A, B, C, D, E, the means of the ratios h / l are respectively 4.7, 5.7, 18.3, 12.6, 10.5. This leads to the inference that Mullus barbatus does not always remain in the same vicinity, but, at times, travels a long way across the Saronikos Gulf. Fish heavily contaminated, migrating within, say, a few weeks to less foul waters would still contain high proportions of the chemicals, since the detoxification process is a slow one. Note that, except perhaps in the instance of a few specimens caught near the sewage outfall, the concentrations of the organochlorine residues stay well below the health hazard limits. They confirm previous work carried out in areas A, B, C, D, by Satsmadjis & Gabrielides (1979) whose data have been, for this reason, incorporated here. They compare also with those found in other polluted regions of the Mediterranean. Thus, the levels of YPCBs, YDDTs and BHCs in the muscle of Mullus barbatus reported by Fossato & Craboledda (1980), concerning various areas of the northern Adriatic Sea, are on the average lower than those listed in Table 1. On the contrary, the ZPCBs and ZDDTs figures quoted by Contardi et al. (1981) for the section of the Ligurian Sea close to Genoa are significantly higher, while those of the YBHCs are smaller. Metals
Table 4 establishes that area A often presents a significant difference from the other areas. Thus, in 20 cases out
of 36, q~> 1.50 (probability at least 93.3°/o) and, in 9 cases out of 36, q>~ 2.50 (probability at least 99.4°7o). However, Table 3 shows that the differences are not only small, but also, excepting area A, do not, as a rule, exhibit a clear trend. In brief, the site affects Fe, Ni, Cu, Co only very slightly, Zn, Cr, Cd to an even smaller extent and Mn not at all. Furthermore, the ratios of the extreme values are not excessive. Thus, the means of h / l for the major constituents (Fe, Zn, Cu, Pb, Mn) in areas A, B, C, D, E are respectively 2.1, 2.1, 2.3, 2.7, 2.9, while, for the remainder of the elements (Ni, Cd, Cr, Co), these means, as expected, are higher: 3.5, 3.4, 4.3, 6.5, 7.4. The impressively small differences between the levels of the metals in various parts of the Saronikos Gulf may have their explanation in the very swift decline of their concentrations in the sediments when getting away from the main sources of pollution, which are the sewage outfall and the fertilizer factory, both in area A (Voutsinou-Taliadouri, 1981). Probably for the same reason, Papadopoulou et al. (1980), working on samples of Mullus barbatus taken from the same region, concluded that the central sewage outfall did not seem to affect the As, Cu and V contents of the fish. Other authors elsewhere in the world made similar remarks. For example, Young et al. (1981) established that the muscle tissues of five popular benthic feeding sportfishes caught near the Los Angeles County municipal wastewater outfalls, analysed for Zn, Cu, Cd, Cr, Pb, Hg, Ni, Ag, exhibited levels not above those measured in island and coastal control specimens, with the possible exception of Zn and Cu.
The authors wish to thank Athanasia Goudjamani-Kyranaki and Eustathius Hadjigeorgiou for helping with the analyses and Basel Marouda-Lambropoulou for drawing the map.
Contardi, V., Zanicchi, G., Mazzone, D. & Magrocosma, B. (1980). Fluctuations saisonni~res de DPC, DDT et m6tabolites dans les organismes de lamer Ligure. In Ves Journ#es Etud. Pollutions, pp. 335-340. Cagliari, C.I.E.S.M. Fossato, V. U. & Craboledda, k. (1980). Chlorinated hydrocarbons in organisms from the Italian Coast of the Northern Adriatic Sea. In Ve~ Journ#esEtud. Pollutions, pp. 169-174. Cagliari, C.I.E.S.M. Holden, A. V. & Marsden, K. (1969). Single-stage clean-up of animal tissue extracts for organochlorine residue analysis. J. Chromat., 44, 481-492. Papadopoulou, C., Zafiropoulos, D. & Grimanis, A. P. (1980). Arsenic, copper and vanadium in Mullus barbatus and Parapenaeus long# rostris from the Saronikos Gulf, Greece. In Vet Journ~es Etud. Pollutions, pp. 419-422. Cagliari, C.I.E.S.M. Satsmadjis, J. & Gabrielides, G. P. (1979). Observations on the concentration levels of chlorinated hydrocarbons in a Mediterranean fish. Mar. Pollut. Bull., 10, 109-111. Satsmadjis, J. & Voutsinou-Taliadouri, F. (1981). Determination of trace metals at concentrations above the linear calibration range by electrothermal atomic absorption spectrometry. Analyt. Chim. Acta, 131, 83-90. Voutainou-Taliadouri, F. (1981). Metal pollution in the Saronikos Gulf. Mar. Pollut. Bull., 12, 163-168. Young, D. R., Moore, M. D., Jan, T.-K. & Eganhouse, R. P. (1981). Metals in seafood organisms near a large California municipal outfall. Mar. Pollut. Bull., 12, 134-138.
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