Environ. Sci. Technol. 1990,24, 498-505
Distribution of Chlorinated Pesticides and Individual Polychlorinated Biphenyls in Biotic and Abiotic Compartments of the Rio de La Plata, Argentina Juan C. Colombo,' Mlchel F. Khalll, Michel Arnac, and Alcide C. Horth
Departement d'ocdanographie, Universitd du Quebec g Rimouski, 3 10, Avenue des Ursulines, Rimouski, Quebec, Canada G5L 3 A 1 Jose A. Catoggio
Centro de Investigaciones del Medio Ambiente, Universidad Nacional de La Plata, Calle 47 y 115, La Plata (1900), Buenos Aires, Argentina
A study of the distribution of chlorinated pesticides (CP) and individual polychlorinated biphenyls (PCBs) in water, sediments, and biota elucidated the sources and the environmental fate of these pollutants. Dissolved CP and PCB concentrations showed a decreasing trend from the industrialized Rio Santiago to offshore stations. Most polluted sediments showed a large contribution of early eluting PCBs. In offshore sediments, congeners with four to six chlorines predominated. Organisms presented maximum levels of p,p'-TDE, -DDT, and -DDE, transchlordane, and of tri- to heptachlorobiphenyls, mainly with the 4,4' recalcitrant bisubstitution. Their organochlorine patterns reflected the integration of the signals observed in water and sediments. Lipid-rich organisms showed a lesser degradation of CPs than low-fat fishes and sediments. Excepting less chlorinated PCBs, which have shorter half-lives, water bioaccumulation factors (BAF) showed a positive correlation with octanol-water partition coefficients (Kow).Sediment BAF-K, relationships were very complex but could be explained by compound sources, elimination and degradation rates, stereochemistry, and KO@. Introduction Chlorinated pesticides (CPs) and polychlorinated biphenyls (PCBs) are ubiquitous contaminants in the aquatic environment. Their fate and distribution among different biotic and abiotic compartments is controlled by their physical-chemical properties, i.e., vapor pressure, octanol-water partition coefficient (Kow),and water solubility (I). Because of their strong hydrophobic (lipophilic) character, these compounds are found mainly associated with colloids (2),suspended particulate matter (SPM) and sediments ( 3 , 4 ) ,and lipid tissues of organisms (5). Due to their ability to accumulate hydrophobic compounds from water and food (6, 7), fish are useful indicators of organochlorine (OCL) contamination. Moreover, contaminated fish constitute a critical route of exposure of humans to high OCL levels (8). Located in the vicinity of La Plata City, the Rio Santiago is a highly industrialized, 8-km-long tributary of the Rio de La Plata. La Plata harbor is a major source of xenobiotics and coastal clay-silty sediments are important reservoirs of anthropogenic hydrocarbons (9). Several species of bottom-feeding fish are consumed by the coastal human population. In this paper, 13 CPs and 67 individual PCB congeners were monitored in water, sediments, and biota. This has permitted a comprehensive assessment of the contamination level, the sources, and the fate of these pollutants in a highly populated coastal zone of Argentina. 498
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Methods Sampling was carried out from September to October 1986, at 17 stations (9). Five were located on the Rio Santiago (Al-A5) and 12 in the Rio de La Plata (Figure 1). Surface and bottom water (1m above the sedimentwater interface) was sampled with 5-L General Oceanic bottles. Surficial sediments (0-5 cm) were concurrently sampled with a 225-cm2stainless steel grab sampler. The bivalve Corbicula fluminea was sampled at stations B6 (a 13-composite sample of 0.7-6-g bivalve) and C10 (a 14composite sample of 0.9-3.4-g bivalve). The fish Oligosarcus jenynsi was collected near station A1 (seven 30.5 f 12.3 g fish). Other fish, Pimelodus albicans (two 7721177-g fish) and Prochilodus platensis 1 (four 841 f 118 g fish), 2 (four 2455 f 546 g fish), and 3 (five 2284 f 148 g fish), were purchased from fishermen in the proximity of station F17. Homogenized sediments were subsampled for the determination of their water content, ignition loss, and grain size composition and for the extraction of organic compounds (9). Water samples (1.5 L) were filtered on preextracted glass fiber filters (1.2 pm) and extracted with three fractions of n-hexane. The marked yellowish color of the filtrates indicated the presence of unfiltrable material, i.e., dissolved organic matter and small particles. Dorsolateral fish muscle subsamples and whole bivalve tissues (10 g), were homogenized, mixed with sodium sulfate, and Soxhlet extracted with an acetoneln-hexane mixture (1:9). Organism extracts were evaporated to dryness under N2,oven-dried for 2 h at 50 "C, and weighed to determine their lipid contents (IO). Purification included chromatography over Florisil and activated copper treatment (9). Extracts with high lipid contents were treated with concentrated sulfuric acid (11). Analyses were carried out on a Perkin-Elmer, Sigma 2000 gas chromatograph equipped with an electron capture detector operating at 320 "C and a 30 m X 0.25 mm J&W fused silica column coated with SE 54. The carrier gas was argon/ methane (95:5), 4 mL/min. Injector temperature was 250 "C. Column temperature was programmed from 50 (2-min hold) to 170 "C (10-min hold) at 15 "C/min, from 170 to 210 "C (2-min hold), and from 210 to 275 "C (2-min hold) at 4 "C/min. Identification of compounds was done by comparison of retention times with authentic standards. The CP standard was a mixture of lindane, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, o,p'and p,p'-DDE, -TDE, and -DDT (PolyScience Corp.). The PCB standard was a mixture of 95 congeners provided by the Netherlands Institute for Sea Research, which was resolved into 67 individual peaks. Identification of congeners 99 and 110
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signed to PCBs 99 and 112 (Figure 3), indicating the presence of cis-chlordane and trans-nonachlor. These peaks were not quantified. Hexachlorobenzene was detected only at low levels. Water values were not significantly different from the blank. HCB levels in sediments (0.13 f 0.09 ng/g) and organisms (0.09 f 0.04 Fg/g) were lower than lindane. The simultaneous determination of PCBs and CPs caused some interferences such as the coelution of PCBs 115-87 and 120 with dieldrin and p,p'-DDE, respectively (Figure 3). Dieldrin presence was considered insignificant since PCB 110/115-87 ratios in the samples (1.87 f 0.8, n = 24) and in the Aroclor standard (1.92) were very close. In contrast, the marked difference of PCB 110/120 ratios in samples (0.8 f 0.3, n = 23) and standard (3.81, indicated the prevalence of DDE. Based on the composition of the Aroclor standard (0.31% of 120) and in total PCB and DDE levels, the contribution of congener 120 to DDE is 1.1-4.6%. Another possible interference exists between cis-nonachlor and TDE. Considering that chlordane patterns in fish resemble the distribution of technical chlordane (13), and based on the trans-chlordanelcis-nonachlor ratio of the formulation, we calculated a cis-nonachlor contribution to TDE of 18.5 f 9.5 and 21.3 f 6.6%, in sediments and organisms, respectively. This is probably an overestimation because samples showed a marked dominance of trans-chlordane over the other related compounds. Recovery assays of the overall procedure were carried out with preextracted sediments spiked with 1ng/g of 11CPs and with 10 ng/g of three Aroclors. The results were 98.3 f 19.4% (n = 11)for CPs and 98.8 f 18.8% (n = 41) for PCBs. Drying sediment samples at 40 "C caused no reduction in the recovery of even the more volatile compounds such as lindane (79.1%) and PCBs 5-8 (ill%), 18 (90.5%), 31-28 (go%), and 41 (100%). Results and Discussion (1) Dissolved Organochlorines. Table I show the concentration of selected PCB congeners, total PCBs, and CPs for the different matrices analyzed. PCB IUPAC numbers (15) joined by a hyphen are coeluting congeners. Owing to the shallow depth (1-10 m) and the strong freshwater discharge [(16-28) X lo3 m3/s] (16) of the Rio de La Plata, the water column is considered homogeneous. This was confirmed by in situ measurements of temperature, pH, and conductivity carried out during sampling (17). Consistently, CP and PCB concentrations measured in surface waters (means in ng/L: PCBs, 20.7; lindane, 21; heptachlor epoxide, 1.8; and p,p'-TDE, 3.6) (17)were similar to those of bottom waters, which are shown in Table I. Due to its high solubility relative to other compounds studied, lindane was dominant in the dissolved phase and was widely detected in concentrations ranging between 0.9 and 61 ng/L. Compound C, an hexachloro component of technical chlordane, was also detected at several stations in relatively high levels (0.4-28 ng/L). Its abundance compared to trans-chlordane ([t-Chl]/[CpC] = 0.16 f 0.13) suggests that these compounds are decoupled in the environment. A fractionation according to their solubilities could produce this effect. The other CPs studied showed lower levels or were under the detection limit at several stations (Table I). PCB concentrations measured in the Rio de La Plata (6.4-56.5 ng/L) are of the same magnitude as those reported for Lakes Superior and Michigan (18) and for the Rhine-Meuse system (19). Maximum OCL concentrations were measured at stations Al, affected by the discharges of El Gat0 stream; A2, which receives chronical inputs from a huge petrochemical complex; and Environ. Sci. Technol., Vol. 24, No. 4, 1990
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A3, located on the main navigation channel of La Plata harbor. Relatively high OCL levels were also detected at coastal stations B6, E16, and F17. The release of hydrophobic OCLs from sediments disturbed by dredging and 500
Environ. Sci. Technol., Vol. 24, No. 4, 1990
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Environ. Sci. Technol., Vol. 24, No. 4, 1990
501
local sediment resuspension. The high OCL levels measured at station E16 could be ascribed to the transport from Rio Santiago through its small west outlet, and to the probable presence of other diffuse coastal inputs. La Plata sewage outfall (station F17) constitutes another source of OCLs, mainly compound C and lindane. Dissolved OCL concentrations show a decreasing trend from the industrialized Rio Santiago to offshore stations where OCL levels are low or nondetectable (B8, C12, B9). Significant negative correlations were found between the distance to station A2 and dissolved lindane ( r = -0.61) and PCBs (r = -0.86) (p = 0.001, n = 17) (Figure 2). This reflects the gradual dilution of polluted La Plata harbor waters with Rio de La Plata waters. The Oeste channel (station A2), main source of PCBs, shows a relatively low lindane level. Stations affected by other OCL sources, B6 (resuspension, PCBs), E16 and F17 (diffuse inputs and sewage outfall, lindane), plot above the regression line. Excluding these sites from the calculations, the correlations increase to r = -0.76 for lindane (y = -3.28~+ 42.4) and r = -0.89 for PCBs (y = -3.45~+ 43.1). In parallel with this decreasing trend in dissolved OCLs, sediment hydrocarbon data (9) showed a gradual transition from petrogenic to pyrogenic polyaromatic hydrocarbon mixtures with distance to station A2. This clearly indicates that La Plata harbor waters are a source of both OCLs and petrogenic hydrocarbons. Dissolved PCB patterns showed the dominance of dito tetrachlorobiphenyls. Congeners 5-8,18,19,52,44, and particularly 14 and 12 (3,5- and 3,4-dichlorobiphenyls), presented the highest levels. The dominance of PCBs 14 and 12 has also been reported for Dutch Wadden Sea waters (20). (2) Sediments. The samples analyzed showed the predominance of p,p’-TDE (0.4-91 ng/g), trans-chlordane (0.2-37 ng/g), and PCBs (2.3-998 ng/g), which were detected at all stations. Heptachlor epoxide, p,p’-DDE, lindane, compound C, and DDT were also detected in several samples (Table I). The abundance of TDE, DDE, and heptachlor epoxide relative to the parent compounds (Table I) indicates that DDT and heptachlor are readily metabolized in sediments. The predominance of TDE over DDE ([TDE]/[DDE] = 1.9 f 0.5) suggests that breakdown of DDT occurred preferentially under anaerobic conditions. The contribution of cis-nonachlor to the TDE peak (< 18%) and the direct introduction of TDE (rhothane), suggested by its high dissolved levels, could also increase this ratio. A high PCB/DDTs ratio (10.9) at station A2 indicates a prevailing industrial contamination. This was clearly demonstrated by hydrocarbon data (9). Lower PCBs/DDTs values of other stations (2.7 f 0.7) show the relative increase of agricultural inputs. The marked dominance of trans-chlordane over compound C ([tChl]/[CpC] = 43 f 59), contrast with the pattern observed in the dissolved phase. This is further evidence for the decoupling of these compounds: compound C, as lindane, is carried mainly in the dissolved phase while transchlordane has a more particle-oriented behavior. The low ratio of station F17 (1.3) reflects the high dissolved load of compound C at this site (Table I). The main factors controlling OCL levels in sediments were the distance from the sources and the grain size composition. OCL values in sediments agree relatively well with the pattern found in the dissolved phase. Maximum concentrations were measured at stations A l , A3, and specially A2, whose PCB levels, 1-2 orders of magnitude higher than other sites, are comparable to those reported for the lower Hudson River ( 4 ) . PCB values of other 502
Environ. Sci. Technol., Vol. 24,No. 4, 1990
stations are similar to those published for sediments of Lakes Huron and Michigan (21). The dominance of trans-chlordane in station A1 (Figure 3C), reflected in its low PCBslt-Chl ratio (2.5), indicate that El Gat0 stream is an important source of this compound. Subsequent surveys confirmed the presence of high chlordane levels (15-80 ng/L) in this stream (22). The high OCL concentrations registered in sediments from station E16, clayey-silt with 4.1 % ignition loss, agree with dissolved OCL data, thus reinforcing the argument of a coastal diffuse source. Station A4, located in a nonindustrialized area, and offshore stations B8, B9, and Cl2 show low OCL levels. Due to the known affinity of OCLs with fine-organic sediments, silty and organic (3.6% ignition loss) sediments from station B7, located in a depression near the mouth of the main channel of Rio Santiago, show relatively high OCL levels. In contrast, coarse sediments from stations B6, C10, D13, D14, D15, and F17 show lower values. The sand fraction of these samples ranged from 78 to 96% (9). The association of OCLs with organic matter is indicated by their significant correlations with the ignition loss: PCB, r = 0.82; p,p’-TDE, r = 0.86; heptachlor epoxide, r = 0.89, (n = 17, p C 0,001). Fine polluted sediments from stations Al, A2, A3, and E16 showed more complete PCB distributions with 38-44 congeners. Sediments from the most contaminated stations, A1 and A2, showed a strong contribution (29.7 and 33.2% of total PCBs, respectively) of di- to tetrachlorobiphenyls 5-8, 12, 26, 31-28, 75-47, 44, 37-42, and 41 (Figure 3C). This suggests the existence of important inputs of less chlorinated Aroclor formulations. In coarse and in offshore sediments, several components were below the detection limits. Offshore stations showed a predominant contribution between tetra- to hexachlorobiphenyls 70-98 and 138 (Figure 4). The percentages of total PCBs represented by each chlorobiphenyl (CBs) group were as follows: di, 6.3 f 5.4; tri, 9.6 f 7.6; tetra, 16.2 f 9.3; penta, 23.6 f 7.1; hexa, 19.8 f 6; hepta, 18.1 f 5.7; octa, 6.1 f 5.5; nona, 0.4 f 0.6 (Figure 5). The most predominant congeners, 31-28,52,70-98,60-92,101,110,149-118,153, 138,128-167,180, and 170, accounted for 47 f 11.1% of the total. Components 60-92 (2,3,4,4’-tetraCB2,2’,3,5,5’-pentaCB), 149-118 (2,2’,3,4’,5’,6-hexaCB2,3’,4,4’,5-pentaCB), and 153 (2,2’,4,4’,5,5’-hexaCB)showed the highest concentrations (Figure 4). (3) Organisms. The organisms analyzed showed detectable residues of 8 chlorinated pesticides (CPs) and 35-46 chlorobiphenyls (Figure 3). Owing to the strong lipophilicity of OCLs, and the variable lipid content of organisms (C. fluminea, 2.4-3.8%; P. platensis, 1-12.7%; P. albicans, 4%; 0. jenynsi, 0.32%), wet weight concentrations showed large variations. Total DDT and PCB values ranged from 3 X to 2.2 and from 0.01 to 1.6 pg/g, respectively. Although these values are below the tolerance limits set for human consumption (2 and 5 p g / g for PCBs and DDT), PCB levels measured in P. platensis 2 and 3 (1.2-1.6 pg/g) are quite high. Consumption of these fish may represent a critical contamination pathway for humans. As expected, lipid-normalized concentrations are less variable (Table I). TDE and DDT attained maximum levels (0.5-10.5 pg/g of lipids) and were followed by trans-chlordane, heptachlor, DDE, compound C, heptachlor epoxide, and lindane. Total PCB concentrations measured in Rio de La Plata organisms (3.3-17.8 pg/g of lipids) are comparable to those reported for lake trout from Lakes Siskiwit and Superior (23). Organisms show a more equilibrated contribution of trans-chlordane and compound C ([t-Chl]/[CpC] = 1.9 f
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DDTs ratios ([DDE]/[DDTs] = 0.2; [TDE]/[DDTs] = 0.46) than sediments (0.3 and 0.6, respectively). These features suggest that the organisms are exposed to other recent DDT inputs. This is certainly possible for the mobile fish, particularly for the migratory P.platensis, but is unlikely for the benthic bivalves. Another process that could accentuate this difference would be a reduced capacity of organisms to degrade DDT, resulting in its preferential preservation. Thus,DDT metabolites in these animals should originate mainly from direct uptake. The similarity of TDE/DDE ratios in organisms (2.1) and sediments (1.9) suggest that the absorption from sediments could be a dominant process. The abundance of transchlordane in sediments ([PCBs]/[t-Chl] = 7.6 4.8) and organisms ([PCBs]/[t-Chl] = 2.8 f 0.4) (Table I, Figure 3) is unexpected since it is known to be less stable than cis-chlordane in the environment (24). This seems to confirm the results obtained with DDT, namely, the existence of recent inputs and the low degradation of CP residues in these organisms. The CP pattern of 0. jenynsi contrasts with the distributions observed in the other organisms. This small, low-fat fish, shows a large reduction of all CP peaks, including those of 99 + cis-chlordane and 112 + trans-nonachlor (Figure 3B). This is reflected in its high PCBs/ DDTs (4.1) and PCBs/t-Chl (10.2) ratios. The low TDE/DDE ratio (1)and the high values of DDE/DDTs (0.5) and HEpo/Hept (3.1; Table I), indicate an extensive degradation of CP residues. Addison and Zinck (25) reported that the dehydrochlorination rate of DDT was inversely correlated with weight and lipid content of fish. Faster turnover of lipid reserves in low-fat fish could release DDT compounds for metabolism. Furthermore, Roberts et al. (26) demonstrated that the tissue retention of chlordane in fish was directly proportional to its adiposity. Other biological factors such as age and trophic habits could also contribute to these differences in the body burden of chlorinated pesticides. PCB patterns showed the dominance of tetra- to heptachlorobiphenyls. The percentages of total PCBs represented by each chlorobiphenyl (CB) group were as follows: di, 7.9 f 10.8; tri, 9.3 f 3.8; tetra, 19.8 f 3; penta, 27 f 6; hexa, 18.9 f 4.5; hepta, 13.8 f 5.3; octa, 2.7 f 1.2; nona, 0.1 f 0.2. Figure 5 shows a plot of the percent contribution of each congener group in sediments and organisms. The dominant tetra- to heptaCBs account for 78-79.5% of the total. The percentages increase from di- to pentaCBs and decrease for more chlorinated congeners. Organisms show higher contributions of tetra- and pentaCBs and lower percentages of hexa- to nonaCBs than sediments. This may reflect the differences in the bioaccumulation rates of the congeners; increasing from tri- to pentaCBs, a slow decrease for hexaCBs, and a substantial reduction for more chlorinated PCBs, which have an unfavorable stereochemistry (27). The dominant PCB congeners, 31-28,52,37-42,60-92, 101, 110, 149-118, 153, 138, 128-167, 180, and 170, accounted for 48-64% of the total. Components 31-28 (2,4’,5-2,4,4’-triCBs), 37-42 (3,4,4’-triCB-2,2’,3,4-tetraCB), 60-92 (2,3,4,4’-tetraCB-2,2’,3,5,5’-pentaCB), and 153 (2,2’,4,4’,5,5’-hexaCB) showed the highest levels (Figure 4). Similar results were published for organisms from Lake Ontario (28) and the Wadden Sea (29,301,although in Rio de La Plata specimens, some tri- and tetraCBs seem to be more abundant. Among the predominant congeners, 10 have the recalcitrant bisubstitution 4,4’ (31): 28, 37, 60, 118, 153, 138, 128, 167, 180, and 170. Other structural characteristics of PCBs that increase their bioconcentration
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Environ. Sci. Technol., Vol. 24, No. 4, 1990 503
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(Figure 6A). Organisms show an enhanced bioaccumulation of heptachlor epoxide, PCB 110, and TDE, which plot above the regression lines, while BAFs of PCB congeners 19,18,26,and 44 are very low and were excluded from the calculations. Increased elimination rates of less chlorinated PCBs (38) may be the cause of these lower BAFs. In juvenile sole, Boon (39) observed the rapid elimination of PCBs 18, 26,44, and 84 with biological half-lives ( t l l z )of 6-24 days while the 4,4'-substituted 118 was more persistent ( t l l z = 67). The slopes of the BAF-KO, relationships are consistently less than unity (Figure 6A). They are comparable to that reported by Neely et al. (33) for trout muscle, log BCF = 0.54 log KO, + 0.124, but P. platensis and C. fluminea BAFs are 1 order of magnitude higher, even expressed on a wet weight basis. BAFs determined in the laboratory are 0.5-2 orders of magnitude lower than those calculated in natural ecosystems where food is a major source of OCLs (34,40,41). In the Rio de La Plata, the contact and the ingestion of sediments, such as the retention of resuspended particles by the filtering bivalve C. fluminea, could play a major role in the transfer of OCLs. P. albicans and particularly P. platensis are iliophagous fish that feed on fine organic muds. The latter show several adaptations that maximize the assimilation of organic matter: sucking mouth, secreting pharyngial diverticles, and labyrinthine intestine with high relief of the mucous membrane. Assimilation efficiencies of 3040% of the organic matter ingested have been reported (42). This feeding behavior favors OCL uptake from sediments. The similarity of PCB patterns in organisms and sediments, specially for higher chlorinated congeners (Figure 4), is consistent with this assumption. Direct water partitioning would be dominant for lindane, compound C, and less chlorinated PCBs. Complex or nonconsistent relationships between organismsediment BAFs and OCL KO@have been reported in the literature (41,43). Figure 6B shows log BAFs (ng/g of lipid-ng/g of dry weight, mean sediment concentration) plotted against log KO$,As expected, sediment log BAFs (1.5-3.8) are lower than water BAFs, indicating the high affinity of sediments (mean ignition loss, 4.5 f 3.6%, n = 16) and lipid tissues for OCLs. Five compound classes can be distinguished in the complex sediment BAF-KO, plot. Lindane show a extremely high BAF. This is probably due to its low sediment affinity (43),suggesting that water uptake is the dominant bioconcentration process. The second group, formed by heptachlor epoxide, DDE, TDE, and DDT with log K d ranging from 5.4 to 5.75, also shows high BAFs. These compounds may have optimal physicochemical characteristics for their bioconcentration. Enhanced bioaccumulation of DDE has been attributed to preferential membrane transport due to a more planar configuration (23) or due to food chain accumulation (40). Increased degradation of CPs in sediments relative to organisms could also contribute to these higher BAFs. The third group, formed by less chlorinated PCBs 15, 19, 18, 26,31-28, and tetra- and pentachlorobiphenyls 44 and 84 (log KO,,4.82-6.04), shows low BAFs. This is consistent with the high elimination rates reported for some of these congeners (39). The octachlorobiphenyl 194, although highly lipophilic (log KO, = 8.68) (44),shows low BAFs. The unfavorable stereochemistryof PCBs with seven or more chlorines may inhibit their uptake across cellular membranes (27). Boon et al. (45) reported similar or even lower BAFs for heptachlorobiphenyls than for congener 44. Finally, tetra- to hexachlorobiphenyls110,52,41,60-92,101,118-149,138, and 153 show a slow increase of the BAFs with increasing
Ked.
The BAF-Kow relationships show significant regression coefficients (0.61-0.91, n = 8) (Figure 6B). Calculated slopes are shallow. They are close to that described for polyaromatic hydrocarbons (0.14) but are lower than that reported for chlorinated compounds (0.34) (46). Differences in fish physiology and in the compounds utilized for the calculations could contribute to this divergence. These results demonstrate that, although complex, organism/sediment BAF-KO, relationships could be useful indicators of the environmental fate of xenobiotics.
Acknowledgments We thank Dr. A. Mariiielarena and Mr. D. Devoto for sampling support, and Dr. P. Beland and J. N. Gearing for their valuable comments on the manuscript. We are particularly grateful to Dr. M. T. J. Hillebrand, from the Netherlands Institute for Sea Research, who generously provided the standard of PCBs. Supplementary Material Available. Tables with all PCB congeners measured are available upon request to the authors. Registry No. PCB-5,16605-91-7;PCB8,25569-80-6; PCB-7, 33284-50-3; PCB-8, 34883-43-7; PCB-14, 34883-41-5; PCB-19, 38444-73-4; PCB-28, 7012-37-5; PCB-31, 16606-02-3; PCB-52, 35693-99-3;PCB-101,37680-73-2;PCB-110,38380-03-9;PCB-153, 35065-27-1; PCB-138, 35065-28-2;PCB-180, 35065-29-3;DDE, 72-55-9;TDE, 72-54-8;DDT, 50-29-3;lindane, 58-89-9 heptachlor epoxide, 1024-57-3;trans-chlordane, 5103-74-2. Literature Cited Mackay, D.; Shiu, W. Y.; Billington, J.; Huang, G. L. In Physical Behavior of PCBs in The Great Lakes; Mackay, D., Paterson, S., Eisenreich, S. J., Simmons, M. S., Eds.; Ann Arbor Science: Ann Arbor, MI, 1983; pp 59-69. Baker, J. E.; Capel, P. D.; Eisenreich, S. J. Environ. Sci. Technol. 1986,20, 1136-1143. Duinker, J. C. Neth. J . Sea Res. 1986,20, 229-238. Bopp, R. F.; Simpson, H. J.; Olsen, C. R.; Kostyk, N. Enuiron. Sci. Technol. 1981, 15, 210-216. Hagel, P.; Tuinstra, L. G. M. Th. Bull. Environ. Contam. Toxicol. 1978, 19, 671-676. Weininger, D. Ph.D. Thesis, University of WisconsinMadison, 1978. Bruggeman, W. A,; Martron, L. B. J. M.; Kooiman, D.; Hutzinger, 0. Chemosphere 1981, 10, 811-832. Swain, W. R. Aquat. Toxicol. 1988,11,357-377. Colombo,J. C.; Pelletier, E.; Brochu, Ch.; Khalil, M.; Catoggio, J. A. Environ. Sci. Technol. 1989, 23, 888-894. Boon, J. P.; Van Zantvoort, M. B.; Govaert, M. J. M. A.; Duinker, J. C. Neth. J. Sea Res. 1985,19, 93-109. Waliszewski, S. M.; Szymczynski,G. A. J. Assoc. Off.Anal. Chem. 1982,65, 677-679. Duinker, J. C.; Hillebrand, M. T. J. Environ. Sci. Technol. 1983,17,449-458. Muir, D. C. G.; Norstrom, R. J.; Simon, M. Environ. Sci. Technol. 1988,22, 1071-1079. Chau, A. S. Y. In Analysis of Pesticides in Water;Chau, A. S. Y., Afghan, B. K., Eds.; CRC Press: Boca Raton, FL, 1982; voi. i, pp 83-172. Ballschmiter, K.; Zell, M. Fresenius 2.Anal. Chem. 1980, 302, 20-31. Urien, C. M. In Environmental Framework of Coastal Plain Estuaries; Nelson, B. W., Ed.; The Geological Society of America, 1972; pp 133, 213-234. Colombo,J. C. M.Sc. Thesis, M 128, Universit.6 du Qugbec I Rimouski, 1987.
(18) Eisenreich, S. J.; Capel, P. D.; Looney, B. B. In Physical Behavior of PCBs in the Great Lakes; Mackay, D., Paterson, s.,Eisenreich, s. J., Simmons, M. s.,Eds.; Ann Arbor Science: Ann Arbor, MI, 1983; pp 181-211. (19) Duinker, J. C.; Hillebrand, M. T. J. Neth. J. Sea Res. 1979, 13,256-281. (20) Duinker, J. C.; Hillebrand, M. T. J. Bull. Environ. Contam. Toxicol. 1983, 31, 25-32. (21) Thomas, R. L.; Frank, R, In Physical Behavior of PCBs in the Great Lakes; Mackay, D., Paterson, S., Eisenreich, S. J., Simmons, M. S., Eds.; Ann Arbor Science: Ann Arbor, MI, 1983; pp 245-267. (22) Catoggio, J. A. CIMA, Universidad Nacional de La Plata, personal communication, 1989. (23) Swackhamer,D. L.; Hites, R. A. Environ. Sci. Technol. 1988, 22,543-547. (24) Kawano, M.; Inoue, T.; Wada, T.; Hidaka, H.; Tatsukawa, R. Environ. Sci. Technol. 1988, 22, 792-797. (25) Addison, R. F.; Zinck, M. E. J. Fish. Res. Board Can. 1977, 34, 119-122. (26) Roberts, J. R.; deFreitas, A. S. W.; Gidney,M. A. J. J. Fish. Res. Board Can. 1977, 34, 89-97. (27) Shaw, G. R.; Connell, D. W. Enuiron. Sci. Technol. 1984, 18, 18-23. (28) Niimi, A. J.; Oliver, B. G. Environ. Sci. Technol. 1989,23, 83-88. (29) Duinker, J. C.; Hillebrand, M. T. J.; Boon, J. P. Neth. J . Sea Res. 1983, 17, 19-38. (30) Boon, J. P.; Duinker, J. C. Aquat. Toxicol. 1985,7,11$134. (31) Zell, M.; Neu, H. J.; Ballschmiter, K. Fresenius 2.Anal. Chem. 1978,292,97-107. (32) Roberts, J. R.; Rodgers, D. W.; Bailey, J. R.; Rorke, M. A. National Research Council Canada, NRCC No. 16077,1978. (33) Neely, W. B.; Branson, D. R.; Blau, G. E. Environ. Sci. Technol. 1974,8,1113-1115. (34) Veith, G. D.; DeFoe, D. L.; Bergstedt, B. V. J. Fish. Res. Board Can. 1979,36, 1040-1048. (35) Mackay, D. Environ. Sci. Technol. 1982, 16, 274-278. (36) Rapaport, R. A.; Eisenreich, S. J. Environ. Sci. Technol. 1984, 18, 163-170; Environ. Sci. Technol. 1985, 19, 376. (37) Duursma, E. K.; Nieuwenhuize, J.; Van Liere, J. M.; Hillebrand, M. T. J. Neth. J. Sea Res. 1986, 20, 239-251. (38) Niimi, A. J.; Oliver, B. G. Can. J. Fish. Aquat. Sci. 1983, 40, 1388-1394. (39) Boon, J. P. In Marine Biology of Polar Regions and Effects of Stress on Marine Organisms; Gray, J. S., Christiansen, M. E., Eds.; John Wiley & Sons: New York, 1985; pp 493-512. (40) Oliver, B. G.; Niimi, A. J. Environ. Sci. Technol. 1985,19, 842-849. (41) Oliver,B. G.; Niimi, A. J. Environ. Sci. Technol. 1988,22, 388-397. (42) Bowen, S. H.; Bonetto, A. A.; Ahlgren, M. 0. Limnol. Oceanogr. 1984,29, 1120-1122. (43) Oliver, B. G. Enuiron. Sci. Technol. 1987, 21, 785-790. (44) Bruggeman, W. A.; Van Der Steen, J.; Hutzinger, 0. J. Chromatogr. 1982, 238, 335-346. (45) Boon, J. P.; Oudejans, R. C. H. M.; Duinker, J. C. Comp. Biochem. Physiol. 1984, 79C,131-142. (46) Connor, M. S. Environ. Sci. Technol. 1984, 18, 31-35. Received for review December 8, 1988. Revised manuscript received May 18,1989. Accepted November 8,1989. Financial support was provided by the Ministere des Relations Znternationales and the Ministere de 1’Enseignement Superieur du Quebec, by the Fonds Institutionnel de Recherche (U.Q.A.R.), and by the Comision de Znvestigaciones Cientificas de la Provincia de Buenos Aires.
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