Levels of polychlorinated biphenyls and pesticides in bluefish before and after cooking

Similar levels of polychlorinated biphenyls (PCBs), pesticides, and fat were found in 20 correlated uncooked and cooked (baked) bluefish fillets. Fillets averaged 2.5 ppm PCBs as Aroclor 1254 (whole basis) before cooking; after cooking, with the oil drippings and skin discarded, the average PCB level was 2.7 ppm. Although PCBs, lipophilic pesticides, and fat were lost along with oil drippings and skin that were discarded after cooking, the moisture loss in the fillets during cooking compensated for these weight losses almost completely. After the fillets were cooked and the oil drippings and skin were discarded, the PCB content of the fillets was 27% lower on the average.     

Organochlorine residues in brook trout from remote lakes in the Northeastern United States

Organochlorine residues were analyzed in brook trout (Salvelinus fontinalis) collected from six undisturbed lakes in Maine, New Hampshire and Vermont. The residues (whole body) were compared among age groups of fish and were correlated by regression analyses with water chemistry factors that might be affected by acid precipitation. There were significant differences in the organochlorine content of fish from different lakes but not among age groups of fish within each lake or among all lakes. There were no significant correlations between the water chemistry values measured and organochlorine content of the fish. Inasmuch as no organochlorine pesticides have been used within the lake watersheds, the compounds must have reached these lakes by atmospheric transport.     

Transport of polychlorinated biphenyls (PCBs) in freshwater mesocosms from sediment to water and air

With sediment as a source the flux of PCBs to water and air was followed in mesocosms with and without fish for two vegetation seasons. The fish represented the largest lipid pool in the mesocosm, and their presence increased the flux of PCBs across the sediment/water interface. The flow of PCBs from sediment to water followed a seasonal pattern with higher rates during summer than in the winter. The rates were governed by the turbation activity of benthic invertebrates, the extent of gas production in the sediment, the amount and quality of the lipid pools in the water column, and the solubility of the PCBs. The greatest amount of PCBs among the lipid pools was found in the dissolved extractable lipids, which also showed the highest concentration of PCBs calculated on a lipid basis. After about 1.5 yr, >90% of the PCBs added was still in the sediment. The remainder was distributed within the mesocosms to various extents depending on the amount and quality of the lipid pools, or transferred into the air. Transfer into the air was governed by PCB concentrations in the water, and by water temperature. The flow was highest during summer, when the surface microlayer renewed its load of PCBs every 8th day.     

Experimental study on the removal of dioxins and coplanar polychlorinated biphenyls (PCBS) from fish oil

Recently, it has been found that fish oils contain a high proportion of contaminants, namely, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (cPCBs). In this study, the removal of contaminants from fish oil by supercritical CO2 extraction (SCE) and by using adsorbents (0.13 wt % of oil) was investigated. Dioxins and cPCBs were extracted from fish oil by SCE at a temperature of 60 degrees C and a pressure of 28 MPa, and the removal efficiencies for PCDDs and PCDFs were in the range of 15-90% and those for cPCBs were in the range of 70-90%. However, 40% of the oil was extracted simultaneously with contaminants. On the adsorbent treatment, activated carbon showed high efficiency, and the removal efficiencies were >90% for PCDDs and PCDFs, but below 30% for cPCBs. A combination of both of these methods is more effective, and almost 100% of the total toxicity equivalence quantity value could be reduced.     

Silicic acid chromatographic separation of polychlorinated biphenyls and pesticides: some contaminants and limitations.

The Armour and Burke method for separating polychlorinated biphenyls (PCBs) from pesticides involves the use of silicic acid. However, we detected di-2-ethylhexyl phthalate, PCBs, and other impurities as interfering contaminants in several batches of silicic acid. The presence of H2SO4 in some batches of silicic acid is inferred. The acid may be responsible for the production of contaminants which interfere in gas-liquid chromatographic analyses. Contaminants in silicic acid are reduced by extracting the adsorbent with solvent, and/or partitioning the concentrated pesticide fraction with 1N NaOH. These purification procedures provide separations relatively free of impurities, but result in reduced adsorbent activity. PCB-pesticide separations are reproducible only within a given batch lot of silicic acid because of the varying adsorbent characteristics of each lot. Alternative adsorbents should be explored for most PCB-pesticide separations.     

Improved Storherr tube for assisted and sweep co-distillation cleanup of pesticides, polychlorinated biphenyls, and pentachlorophenol from animal fats

A procedure is presented for the simultaneous extraction from animal fat and quantitation of 15 pesticide residues, 4 polychlorinated biphenyl (PCB) formulations, and pentachlorophenol (PCP). Silanization of the Storherr tube packing reduces thermal decomposition and allows for residue recoveries in excess of 88% from pork, beef, chicken, sheep, and rabbit fat. This Storherr tube performs well in either the assisted distillation or sweep co-distillation mode of operation. Detection limits of 2-5 ppb for the pesticides and 10 ppb for the PCBs are readily attained.     

Single-laboratory evaluation of EPA method 8080 for determination of chlorinated pesticides and polychlorinated biphenyls in hazardous wastes

Method 8080, as published in the Second Edition of "Test Methods for Evaluating Solid Waste," EPA Manual SW-846, has been evaluated in a single-laboratory study. The Florisil procedure recommended in Method 8080 for sample cleanup does not separate organochlorine pesticides (OCPs) from the polychlorinated biphenyls (PCBs). Consequently, gas chromatographic analysis of OCPs on the packed column recommended in the method may result in false identifications or in no identifications at all when PCBs are present. Therefore, silica gel was substituted for Florisil, a capillary column was substituted for the packed column, and a sulfur cleanup procedure was incorporated in the method. The revised method was evaluated with samples spiked at 3 concentrations. Precision and accuracy indicate that the revised method can be reliably applied to the determination of OCPs and PCBs in liquid and solid matrixes. Detection limits for liquid matrixes range from 0.02 to 0.09 micrograms/L for OCPs and from 0.5 to 0.9 micrograms/L for PCBs. Detection limits for solid matrixes range from 1 to 6 micrograms/kg for OCPs and from 60 to 70 micrograms/kg for PCBs.     

Wetlands of the Interior Southeastern United States: Conference summary statement

The wetland resources in the southern United States are diverse, being characterized by bottomland hardwoods, forested riparian zones, swamps, marshes, bogs, and fens. Recognizing the importance of the wetland resource, the need to develop information on the diversity of wetland types, and the evolving public debate regarding the protection and management of wetlands, this conference was organized to (1) provide a forum for the presentation and discussion of current research and information on wetland ecosystems, (2) to develop a basis on which to improve wetland conservation and management, (3) to provide a forum to encourage collaboration in the study and management of wetland resources, and (4) to suggest actions that would benefit wetland conservation and management. Twenty-three invited technical papers and three working group sessions addressed topics encompassing the full spectrum of wetland issues, including resource status, ecological and hydrological processes, management and conservation, and restoration and creation. Major findings discussed at the conference included the need to distinguish between functions and values, the development of a hydrogeomorphic classification system for assessing wetland functions, and assessment methodologies for planning and implementing effective wetland restoration projects. Papers summarizing the current understanding of wetland soil and vegetation processes in the region highlighted the important role wetlands play in landscape function, yet the understanding of those processes is incomplete. Insights developed from the study of wetlands in the interior southeastern United States have widespread applicability to other regions because of similarities in hydrogeomorphic setting and vegetation communities, and the management and conservation issues.     

Toxic potency of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in food samples from Catalonia (Spain)

A surveillance program on polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in 29 foodstuff samples produced all over the four provinces in Catalonia (Spain) is presented. The study included the analyses of milk, egg, meat (beef, chicken, and pork), mussel, and olive oil samples. A previously developed method for the simultaneous analysis of the 2,3,7,8-substituted PCDDs/PCDFs and the dioxin-like PCBs, as well as the indicator PCBs, was employed. Total toxicity equivalent (TEQ) values were calculated using the toxicity equivalent factors (TEFs) proposed by the World Health Organization (WHO) for dioxin-like PCBs, PCDDs, and PCDFs. The TEQ(PCDD/F) levels were below the limits proposed in the draft of the EC regulation for food commercialization in the European countries. These limits are the following: 2 pg WHO-TEQ/g fat for pork, 3 pg WHO-TEQ/g fat for milk and chicken, 5 pg WHO-TEQ/g fat for egg and beef, and 3 pg WHO-TEQ/g whole product for fish. The contributions of PCDDs/Fs and dioxin-like PCBs in the total toxicity of the samples were calculated for each matrix. The results showed that the TEQ(PCB) contribution varied from 27% in olive oil samples to 81% in mussel samples. These findings suggest that the regulation of TEQ contents in food should include not only the TEQ(PCDD/F), but also the TEQ(PCB).     

Coplanar polychlorinated biphenyls in aroclor and kanechlor mixtures

Three congeners of coplanar PCBs (non-o-o'-chlorine-substituted polychlorinated biphenyls) were determined in representative commercial PCB preparations. The 3,3',4,4'-tetrachlorobiphenyl was highest in Kanechlor 400 (8500 micrograms/g) and Aroclor 1248 (6060 micrograms/g) followed by Kanechlors 300, 500, and 600 and Aroclors 1242, 1254, and 1260 in that order. The toxic 3,3',4,4',5-pentachlorobiphenyl and 3,3',4,4',5,5'-hexachlorobiphenyl were also detected in those mixtures. The highest concentrations of 3,3',4,4',5-pentachlorobiphenyl were found in Kanechlor 400 (89.3 micrograms/g) and Aroclor 1248 (62.3 micrograms/g) followed by Kanechlors 500, 300, and 600 and Aroclors 1254, 1242, and 1260 in that order. The 3,3',4,4',5,5'-hexachlorobiphenyl was detected in all Kanechlor mixtures, with the highest concentration (1.16 micrograms/g) in Kanechlor 500. However, among Aroclor mixtures, it was detected only in Aroclor 1254 at a concentration of 0.66 micrograms/g. The importance of these toxic constituents in PCB mixtures is worth considering in view of widespread pollution of the environment by PCBs.     

Sulfuric acid cleanup and KOH-ethanol treatment for confirmation of organochlorine pesticides and polychlorinated biphenyls: application to wastewater samples

The efficacy of sulfuric acid cleanup and KOH-ethanol hydrolysis confirmation was studied for 22 organochlorine pesticides and 2 polychlorinated biphenyls (PCBs). Mean recoveries for different treatment times are given. The method was applied to analysis of several wastewater samples by gas chromatography with electron capture detection. Organochlorine compounds were extracted by using separatory funnels and 15% diethyl ether in hexane as extractant. All the compounds studied could be analyzed except trifluralin, dichloran, dieldrin, and endrin, which were destroyed after treatment with concentrated H2SO4. The pesticides found most commonly in the samples analyzed were fenson, tetradifon, lindane, methoxychlor, and dicofol.     

Coexposure of dioxin-like polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and dibenzofurans in free-range hens and implications derived from congener profile analysis

The consumption of free-range eggs is becoming more popular worldwide. We analyzed the levels of 12 dioxin-like polychlorinated biphenyls (dl-PCBs) and their congener profiles from 6 free-range and 12 caged egg samples. The mean levels of dl-PCBs in the free-range samples were 5.4 times higher than those in caged eggs. All egg samples exhibited at least two characteristic dl-PCB congener patterns, which reflected distinctive contamination sources. Additionally, for the first time, we demonstrated that the dl-PCB levels in the free-range eggs were highly correlated with elevated levels of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) (r = 0.986; p < 0.001), indicating a coexposure scenario in free-range hens. Cluster analysis of congener patterns implied that this coexposure scenario could be attributed to distinct dl-PCB and PCDD/F sources. This congener profile information provides insights from a different perspective for further identifying potential dl-PCB and PCDD/F sources in the polluted free-range eggs.     

Residues of organochlorine pesticides in fish from the Arabian Gulf

High-resolution electron capture gas chromatography was used to determine residue levels of organochlorine pesticides in 13 commercially important fish species collected from the NW Arabian Gulf. While most of the residues were below the detection limit of 1 μg kg^?1 wet weight, relatively low concentrations of ΣDDT, endrin and dieldrin were detected in the edbile tissue of these fishes. The ΣDDT residue levels ranged from 2 to l 1μg kg^?1 wet weight, endrin ranged from none detected (nd) to 45 μg kg^?1 and dieldrin from nd to 5 μg kg^?1. A definite correlation was established between total organochlorine pesticide residues and lipid content (r = 0.6) for the NW Arabian Gulf fishes. Comparison with fish from Hor-al-Hammar Lake (an area that used to be sprayed with pesticides) has shown that the latter contained significantly higher residue levels. The ΣDDT residue levels ranged from 5 to 45 μg kg^?1 wet weight, endrin from 3 to 83 μg kg^?1 and dieldrin from nd to 4 μg kg^?1 Based upon the observation that the original DDT (p, p′-DDT) was identified in the NW Arabian Gulf fishes, it has been concluded that there was a recent input of DDT to this region. Since DDT application has been banned in Iraq, consequently it was assumed that DDT must originate from a more remote source.     

Evidence of fish population responses to acidification in the Eastern United States

The hypothesis that acidification has reduced or eliminated fish populations in certain areas of the eastern United States was investigated by examining present and historical fishery survey records. The causes of acidification (e.g., atmospheric deposition) were not specifically considered, although instances of obvious alternative explanations (e.g., acid mine drainage, organic acids) were avoided. The number of usable data sets located was small. Trend analyses are severely limited by the lack of high quality historical data. The strongest evidence for fisheries declines associated with acidification is provided by data for the Adirondack Mountain region of New York. In some lakes, fish populations have declined or disappeared; lakes experiencing fishery declines are now acidic. Alternative explanations for changes in fish communities over time were examined. In 49 lakes, some or all fish populations have apparently been lost with no available explanation other than acidification. Extrapolation of these data to the entire Adirondack Mountain region suggests that perhaps 200 to 400 lakes may have lost fish populations as a result of acidification. Streams in Pennsylvania and Massachusetts also had documented declines in fish populations that were associated with acidity; however, the data are fewer and less complete than those for New York. Acidification effects on fishery resources in other regions of the eastern United States are apparently minimal. The extent of the damage to date appears small relative to the total resource.     

Concentration and distribution of polychlorinated biphenyls in soils of Moscow

The concentration of polychlorinated biphenyls (PCB) in the soils of Moscow has been determined by gas chromatography and high-resolution mass spectrometry (GC-HRMS). The total concentrations of 19 indicator and dioxin-like congeners, as well as PCBs in surface soils, are 2.85–60.62 μg/kg (the most contaminated sample was 4591.99 μg/kg). The average value, excluding the most contaminated sample, is 14.44 μg/kg, which is characteristic of residential areas of industrialized countries. This indicator varies insubstantially depending on the functional zone of the city. The toxicity equivalent of 12 dioxin-like PCBs in soils is 1.92 ng I-TEQ/kg on average and varies in a range from 0.15 to 334.12 ng I-TEQ/kg. The fraction of PCBs in the total toxicity of dioxins and dioxin-like compounds in soil varieties is 16.7–85.4%.