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Archives of Environmental Contamination and Toxicology (v.52, #4)
Mass Flow of Polycyclic Musks in Two Wastewater Treatment Plants by J. L. Reiner; J. D. Berset; K. Kannan (pp. 451-457).
Synthetic musks are found in varying amounts in many consumer products. After use, synthetic musks go down the drain into the sewer system and then reach wastewater treatment plants (WWTPs). In this study, mass flows of two synthetic polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[γ]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), along with HHCB-lactone (the oxidation product of HHCB) were examined in two WWTPs. Wastewater and sludge samples were collected at various stages of the treatment process for analysis. HHCB, AHTN, and HHCB-lactone were found in all wastewater samples at concentrations in the ranges of 1780 to 12700, 304 to 2590, and 146 to 4000 ng/L, respectively. The highest concentrations for all compounds were found in sludge samples. Sludge samples contained HHCB at 7.23 to 108 mg/kg dry weight, AHTN at 0.809 to 16.8 mg/kg dry weight, and HHCB-lactone at 3.16 to 22.0 mg/kg dry weight. This is the first study to report HHCB-lactone in wastewater and HHCB, HHCB-lactone, and AHTN in sludge in WWTPs from the United States. HHCB and AHTN concentrations decreased during treatment. However, the concentrations of HHCB-lactone increased in water after treatment. Based on the daily flow rates and mean concentrations of the three compounds in effluent, a WWTP representative of those studied here is expected to release 288 g HHCB, 60.4 g AHTN, and 158 g HHCB-lactone/100,000 people/d. Partitioning HHCB, AHTN, and HHCB-lactone to sludge is the major removal mechanism for polycyclic musks in WWTPs.
Persistent Organic Pollutants in Sediments from Sai Gon–Dong Nai River Basin, Vietnam: Levels and Temporal Trends by Nguyen Hung Minh; Tu Binh Minh; Hisato Iwata; Natsuko Kajiwara; Tatsuya Kunisue; Shin Takahashi; Pham Hung Viet; Bui Cach Tuyen; Shinsuke Tanabe (pp. 458-465).
Surficial sediment samples were collected from Hochiminh City canals, the Sai Gon–Dong Nai River, and its estuary, one of the most predominant industrial areas in Hochiminh City, southern Vietnam, for determination of selected persistent organic pollutants (POPs). Contamination pattern was as follows: PCBs ≥ DDTs > HCB > CHLs > HCHs. Concentrations of PCBs and DDTs ranged from 0.50–150 ng/g and 0.15–72 ng/g dry wt, respectively. On the other hand, concentrations of CHLs, HCHs, and HCB were mostly <2 ng/g dry wt. Levels of the all organochlorines (OCs) in Hochiminh City canals were significantly higher than those in the other areas, indicating the urban areas as major pollution sources to the aquatic environment. The contamination pattern was PCBs > DDTs in the city canals but PCBs < DDTs in the downstream and the estuary, suggesting particularly high contamination by PCBs in the city. Examination of DDTs composition and their ratios demonstrated continuous input of this pesticide to the city canals. However, the combination of our data and those from available literature implies a decreasing trend of PCBs and DDTs in the environment. DDTs concentrations have been reduced 50% after approximately 5 years. Composition of CHLs in the sediment from Hochiminh City canals was comparable to those of common technical mixtures, suggesting continuous input of CHLs to the environment. CHLs might be in use for purposes like termite control, wood preservation, and protection of underground cables. Hazard assessment implies high toxic potential of DDTs for sediments from Hochiminh City canals and suggests the need for better management of municipal discharges.
Keywords: Persistent organochlorine; Sediment; Temporal trend; Vietnam
Distribution of Chlorinated Organic Pollutants in a Wide Variety of Soils from Europe and Asia: A Multivariate Statistical Approach by B. Škrbić; N. Đurišić-Mladenović (pp. 466-474).
Principal component analysis was used to interpret the levels of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) previously determined in a wide variety of soils from Europe and Asia to (1) examine the interdependencies among them and chosen soil charaeteristics and (2) reveal PCB– and OCP–soil patterns throughout Europe and Asia. Loading values suggested correlations between the levels of certain compounds and soil characteristics, revealing the underlying structure of analyzed data; humus content, pH, and density correlated with the contents of p,p’-DDT, β-hexachlorocyclohexane (HCH) and γ-HCH, and clay content correlated with the concentrations of α-HCH and PCB 28. Component scores reflected relatively low concentrations of six “marker” PCBs in most of the soils, pointing out the outliers in the proximity of the local PCB sources. PCB loads in the 1990s and early 2000s were lower than the ones in 1980 and 1956, and they coincided with the soil levels in 1944. PCBs 138, 153, and 180 had the greatest influence of the six investigated congeners on soil-pattern differences. In relation to the OCP soil loads, the score plot revealed regions with recent and/or enhanced application of DDT and HCH.
Arsenic Fractionation and Bioaccessibility in Two Alkaline Texas Soils Incubated with Sodium Arsenate by Rupali Datta; Konstantinos C. Makris; Dibyendu Sarkar (pp. 475-482).
Elevated arsenic (As) concentrations in urban soils with prolonged arsenical pesticide application history have increased the risk associated with accidental hand-to-mouth soil ingestion by children. Earlier work by the authors suggested that the conservative statement of 100% As bioaccessibility in soils was not valid for a set of acidic soils incubated with sodium arsenate. In this study, two alkaline Texas soils incubated with a commonly used As pesticide (sodium arsenate) were evaluated for their potential in reducing soil As bioaccessibility. The objective of this study was to evaluate the effects of incubation time and As load on soil As fractionation and bioaccessibility. Soils were subjected to a sequential As fractionation scheme, and bioaccessible As was quantified using an in vitro stomach phase test. Results showed a reduction in the water-soluble As fraction with incubation time (after 4 months), which remained unchanged after 12 months. This reduction with time was accompanied by an increase in the NaOH- and H2SO4-extractable As fractions, suggesting As sorption by amorphous Fe/Al hydroxides and/or Ca/Mg compounds, respectively. Organic/sulfides-bound As increased with incubation time after 12 months but not after 4 months of incubation. The aging effect was also observed with the amount of bioaccessible As at all As loads, showing significant positive correlations with the water-extractable and exchangeable As fractions. Bioaccessible As concentrations even after 12 months of incubation were not significantly reduced, suggesting that natural attenuation might prove inadequate to control As bioaccessibility in these alkaline soils.
Keywords: Arsenic; Pesticide; Speciation; Bioaccessibility; In-vitro; Fractionation
Biological and Electrochemical Treatment of Used Metalworking Fluids: A Toxicity-Reduction Evaluation by A. Muszyński; M. Załęska–Radziwiłł; M. Łebkowska; D. Nowak (pp. 483-488).
The aim of this study was to evaluate and compare the toxicity of spent metalworking fluids (MWFs) and two different effluents obtained by biologic and electrochemical treatment of spent MWFs toward aquatic organisms of different trophic levels. The obtained toxicity data was used to calculate safe concentrations of both effluents. The spent MWFs without treatment showed the highest toxicity among the tested samples and should be classified as “extremely toxic” (toward invertebrates) or “very toxic” (toward other test organisms). Both methods applied for MWFs treatment resulted in a significant decrease in toxicity of the treated MWFs, but the obtained effluents had still to be regarded as “toxic”. The ranges of the values of acute toxic units for both effluents were significantly narrower than for the untreated spent MWFs. The values of the safe concentrations of the spent MWFs, the biologic effluent, and the water phase resulting from electrochemical emulsion breaking were equal to 0.013%, l.8%, and 1.3%, respectively, corresponding to chemical oxygen demand concentrations of 1.8%, 32, and 34 mg O2*L−1. These values are far lower than the discharging limit of 125 mg O2*L−1 for industrial effluents, according to the relevant Polish regulations. It is therefore recommended to include toxicity bioassay parameters into guidelines for wastewater discharges to surface waters because the existing chemical and physical parameters are not sufficient to describe the environmental impact of industrial wastewater. Toxicity bioassays can be a promising tool for evaluating the efficacy of unit operations in industrial wastewater treatment (toxicity reduction evaluation) as well as identification of toxic substances in effluents (toxicity identification evaluation).
Microcystin Concentrations in the Nile River Sediments and Removal of Microcystin-LR by Sediments During Batch Experiments by Zakaria A. Mohamed; Hassan M. El-Sharouny; Wafaa S. Ali (pp. 489-495).
During the present study, microcystin (MCYST) concentrations in the Nile River and irrigation canal sediments, Egypt, were investigated during the period January–December 2001. Batch experiments were also conducted to confirm the adsorption of MCYSTs on these sediments. The results of field study showed that MCYST concentrations in the sediments were correlated with total count of cyanobacteria, particularly Microcystis aeruginosa, and MCYST within phytoplankton cells in most sites. No detectable levels of MCYSTs were found in the cell-free water of all studied sites in the Nile River and irrigation canals during the entire study period. The data obtained from batch adsorption experiments confirmed the capability of the Nile River and irrigation canal sediments for MCYST adsorption; and that adsorption was sediment weight-dependent and thus fitted the Freundlich adsorption isotherm. The results also revealed that both adsorption capacity (Kf) and intensity (1/n) varied significantly with clay and organic matter contents of these sediments. The results of present study have two implications. First, the presence of cyanobacterial toxins in freshwater sediments can affect benthic organisms inhabiting these sediments, and thus it should be considered during biological monitoring of rivers and streams. Second, the ability of freshwater sediments to adsorb cyanobacterial toxins suggests that bank filtration could be used in developing countries (e.g., Egypt), which require an inexpensive and low-maintenance method for removing these toxins from drinking water.
Liming Effects on Cadmium Stabilization in Upland Soil Affected by Gold Mining Activity by Chang Oh Hong; Do Kyoung Lee; Doug Young Chung; Pil Joo Kim (pp. 496-502).
To reduce cadmium (Cd) uptake of plants cultivated in heavy metal–contaminated soil, the best liming material was selected in the incubation test. The effect of the selected material was evaluated in the field. In the incubation experimentation, CaCO3, Ca(OH)2, CaSO4·2H2O, and oyster shell meal were mixed with soil at rates corresponding to 0, 400, 800, 1600, 3200 mg Ca kg−1. The limed soil was moistened to 70% of field moisture capacity, and incubated at 25°C for 4 weeks. Ca(OH)2 was found to be more efficient on reducing soil NH4OAc extractable Cd concentration, due to pH increase induced net negative charge. The selected Ca(OH)2 was applied at rates 0, 2, 4, 8 Mg ha−1 and then cultivated radish (Raphanus sativa L.) in the field. NH4OAc extractable Cd concentration of soil and plant Cd concentration decreased significantly with increasing Ca(OH)2 rate, since alkaline-liming material markedly increased net negative charge of soil induced by pH increase, and decreased bioavailable Cd fractions (exchangeable + acidic and reducible Cd fraction) during radish cultivation. Cadmium uptake of radish could be reduced by about 50% by amending with about 5 Mg ha−1 Ca(OH)2 without adverse effect on radish yield and growth. The increase of net negative charge of soil by Ca(OH)2 application may suppress Cd uptake and the competition between Ca2+ and Cd2+ may additionally affect the suppression of Cd uptake.
Accumulation and Distribution of Trivalent Chromium and Effects on Hybrid Willow (Salix matsudana Koidz × alba L.) Metabolism by X.-Z. Yu; J.-D. Gu (pp. 503-511).
The metabolic response of plants to exogenous supply and bioaccumulation of trivalent chromium (Cr3+ ) was investigated. Pre-rooted young hybrid willows (Salix matsudana Koidz × alba L.) were exposed to hydroponic solution spiked with CrCl3 at 24.0°C ± 1°C for 192 hours. Various physiologic parameters of the plants were monitored to determine toxicity from Cr exposure. The transpiration rate of willows exposed to 2.5 mg Cr/L was 49% higher than that of the untreated control plants, but it was decreased by 17% when exposed to 30.0 mg Cr/L. Significant decrease (≥20%) of soluble protein in young leaves of willows was detected in the treatment group with ≥7.5 mg Cr/L. The measured chlorophyll contents in leaves of treated plants varied with the dose of Cr, but a linear correlation could not be established. The contents of chlorophyll in leaves of willows exposed to ≥7.5 mg Cr/L were higher than that of the untreated plants but lower at 30.0 mg Cr/L. Superoxide dismutase activity (SOD) in leaves between the treated and untreated willows did not show any significant difference, but activities of both catalase (CAT) and peroxidase (POD) in leaf cells of all treated plants were higher than those in the untreated willows. The correlation between the concentration of Cr and CAT activity in leaf cells was the highest of all toxicity assays (R 2 = 0.9096), indicating that CAT activity was most sensitive to the change in Cr3+ doses compared with the other selected parameters. Results from the Cr uptake study showed that significant removal of Cr from hydroponic solution was observed in the presence of hybrid willows without showing detectable phytotoxicity, even at high does of Cr. More than 90% of the applied Cr3+ was removed from the aqueous solution by willows at concentrations up to 7.5 mg Cr/L. Approximately 70% of the initial Cr was recovered in the plant materials. At the low-Cr3+ treatment (2.5 mg Cr/L), Cr accumulation by willow materials was the greatest (92%) in roots and the lowest (0.2%) in leaves, whereas the greatest (66%) was in stems and the lowest (0.1%) in leaves of willows exposed to 30.0 mg Cr/L. The correlation between applied Cr3+ (mg Cr/L) and Cr (μg Cr/g fresh weight [fw]) accumulated in plant materials was significant. The bioaccumulation kinetics of Cr by hybrid willows can be described by a typical saturation curve. Results also indicated that translocation of Cr from roots to shoots was possible. It is to conclude that hybrid willows have great potential as bioremediation technology in the removal of chromium (Cr3+) from contaminated effluents and sediments.
Polybrominated Hexahydroxanthene Derivatives (PBHDs) and Other Halogenated Natural Products from the Mediterranean Sponge Scalarispongia scalaris in Marine Biota by Joachim Melcher; Dorte Janussen; Mary J. Garson; Josef Hiebl; Walter Vetter (pp. 512-518).
Structures of polybrominated hexahydroxanthene derivatives (PBHDs) previously detected in commercial fish from the Mediterranean Sea and mussels from New Zealand were assigned to 2,7-dibromo-4a-bromomethyl-1,1-dimethyl-2,3,4,4a,9,9a-hexahydro-1H-xanthene (TriBHD) and 2,5,7-tribromo-4a-bromomethyl-1,1-dimethyl-2,3,4,4a,9,9a-hexahydro-1H-xanthene (TetraBHD) by comparing their gas chromatography/mass spectrometry (GC/MS) features with isolates from an Australian sponge of the Cacospongia genus. Because of the geographic distance between the Mediterranean Sea in Europe (origin of the fish) and Australia (origin of the sponge), a closely related sponge, Scalarispongia scalaris, was collected in the Mediterranean Sea and analyzed for PBHDs and other halogenated compounds. The Mediterranean sponge contained the PBHDs at 37 mg/kg dry weight. Using quantitative standards for the first time, the PBHD concentrations in fish and mussel samples published earlier were re-examined. Concentrations of up to 1 mg/kg TriBHD and 0.5 mg/kg TetraBHD were determined in the lipids. No correlation with 2,2′, 4,4′, 5,5′-hexachlorobiphenyl (PCB 153) or p,p’-DDE was found, which is in agreement with other marine halogenated natural products detected in the fish samples. Besides the PBHDs, further unknown halogenated compounds were detected in the Mediterranean sponge, some of which were also detected in commercial fish. GC/electron ionization-MS analysis showed that a major mixed-halogenated compound in the sponge had a molecular ion at m/z 480 and contained three bromines, three chlorines, and 9–10 carbons. No corresponding structure has been described for this feature in the scientific literature. This sponge secondary metabolite and potential novel halogenated natural product was also detected in commercial fish. Another prominent mixed halogenated compound detected both in sponge and fish was the dibromotrichloro monoterpene MHC-1 (C10H13Br2Cl3).
Application of Chemometric Studies to Metal Concentrations in Molluscs from the Strait of Magellan (Chile) by M. S. Astorga España; E. M. Rodríguez Rodríguez; C. Díaz Romero (pp. 519-524).
Na, K, Ca, Mg, Fe, Cu, Zn, Mn, Se, Ni, and Cd concentrations were determined in 126 mollusc samples belonging to five different species (Mytilus chilensis, n = 47; Nacella deaurata, n = 65; Aulacomya ater, n = 4; Fissurella picta, n = 4; Acanthina monodon, n = 6) collected from the coasts of the Strait of Magellan. The metals analysed presented significant differences between the mean concentrations for the mollusc species considered. Factor and discriminant analyses made possible the differentiation of the mollusc species. In addition, when discriminant analysis was used, good classifications were obtained according to sampling zone and weight-to-length ratio of the organisms.
The Effect of Tributyltin-Oxide on Earthworms, Springtails, and Plants in Artificial and Natural Soils by J. Römbke; S. Jänsch; T. Junker; B. Pohl; A. Scheffczyk; H.-J. Schallnaß (pp. 525-534).
Chemical bioavailability in Organisation for Economic Co-operation and Development (OECD) artificial soil can contrast with bioavailability in natural soils and produce ecotoxicologic benchmarks that are not representative of species’ exposure conditions in the field. Initially, reproduction and growth of earthworm and Collembolan species, and early seedling growth of a dicotyledonous plant species, in nine natural soils (with a wide range of physicochemical properties) and in OECD soil were evaluated. Soils that supported reproduction and growth of the test species were then used to investigate the toxicity of tributyltin-oxide (TBT-O). Natural soils caused greater toxicity of TBT-O to earthworms (EC50 values varied from 0.5 to 4.7 mg/kg soil dry weight [dw]) compared with toxicity in OECD soil (EC50 = 13.4 mg/kg dw). Collembolans were less sensitive to TBT-O than earthworms in natural soils, with EC50 values ranging from 23.4 to 177.8 mg/kg dw. In contrast, the toxicity of TBT-O to collembolans in OECD soil (EC50 = 104.0 mg/kg dw) was within the range of EC50 values in natural soils. Phytotoxicity tests revealed even greater difference between the effects in natural soils (EC50 values ranged from 10.7 to 189.2 mg/kg dw) and in OECD soil (EC50 = 535.5 mg/kg dw) compared with results of the earthworm tests. Studies also showed that EC50 values were a more robust end point compared with EC10 values based on comparisons of coefficients of variation. These results show that toxicity testing should include studies with natural soils in addition to OECD soil to better reflect exposure conditions in the field.
Cadmium Exposures in Fathead Minnows: Are There Sex-Specific Differences in Mortality, Reproductive Success, and Cd Accumulation? by Marlo K. Sellin; Tess M. Eidem; Alan S. Kolok (pp. 535-540).
The primary goal of this experiment was to determine whether cadmium (Cd) exposure has sex-specific effects on the reproductive success of fathead minnows as measured by time to first spawn, spawning frequency, clutch size, fecundity, fertilization success, hatching success, and offspring mortality to 2 d post hatch. Prior to breeding, minnows were either exposed to 50 μg/L Cd or sham exposed for 21 d. After exposures, minnows were paired (male × female) into one of four breeding groups—control × control (C × C), control × exposed (C × E), exposed × control (E × C) or exposed × exposed (E × E). Pairs of minnows were subjected to a 21-d breeding study during which the reproductive parameters mentioned above were measured. During the breeding study, minnows in the E × E pairs had significantly higher mortality than minnows in the C × C pairs; however, the mortality of minnows in the C × E and E × C did not differ from that of C × C pairs. Presumably, behavioral alterations in both males and females exposed to Cd accounted for the increased mortality in the E × E group. The results of the breeding study did not reveal any significant differences among any of the reproductive parameters measured with the exception of offspring mortality. Offspring from C × E pairs did not differ from offspring from C × C pairs with regard to mortality; however, offspring from pairs containing exposed males (E × C and E × E) had significantly higher mortality than offspring from C × C pairs suggesting that paternal exposure to Cd leads to an increase in offspring mortality.
Bioaccumulation and Elimination of Hg in the Fireworm Eurythoe complanata (Annelida: Polychaeta) from Mazatlan, Mexico by Ramón Vázquez-Núñez; Nuria Méndez; Carlos Green-Ruíz (pp. 541-548).
Mercury accumulation and elimination by Eurythoe complanata were evaluated through two laboratory bioassays in the absence (bioassay A) and presence (bioassay B) of sediment. Ten individuals per treatment (three replicates) were exposed to Hg in solution (0, 1.5, 1.7, 3, 7.4, 8.7, 9, and 11 μg/L) for an 8-day exposure period. At the beginning of the elimination period, the solutions (both bioassays) and sediments (bioassay B) were replaced by seawater only and clean sediment, respectively. This period lasted 8 days. The effect of Hg concentrations on Hg accumulation by worms from bioassay A was confirmed by the Kruskal-Wallis test (H = 19.43, df = 7, χ2 = 18.475, p = 0.01), whereas this effect was nonsignificant for bioassay B. Specimens from bioassay A accumulated about double the Hg than those of bioassay B. This indicates that sediment plays an important role in the bioaccumulation process. Mercury elimination was observed only on specimens from bioassay B, where 25% to 36% of the total Hg was eliminated during 8 days. This suggests that worms need a longer period of time to completely depurate the accumulated Hg. The Hg balance was performed at the beginning and end of the experimental periods. The total Hg percentage per aquarium decreased at the end of the experiment, which suggests that a considerable amount of Hg was evaporated or adhered to the aquarium walls. This first approach points out that experimental studies using E. complanata as a test species can be useful to evaluate the potential risk produced by Hg or other toxicants on marine biota inhabiting zones subjected to anthropogenic activities.
Biomarkers of Contaminant Exposure in Northern Pike (Esox lucius) from the Yukon River Basin, Alaska by J. E. Hinck; V. S. Blazer; N. D. Denslow; M. S. Myers; T. S. Gross; D. E. Tillitt (pp. 549-562).
As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p’-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P < 0.01). Vitellogenin concentrations in female (0.09 to 5.32 mg/mL) and male (<0.0005 to 0.097 mg/mL) pike were not correlated with any contaminant, but vitellogenin concentrations >0.01 mg/mL in male pike from multiple sites indicated exposure to estrogenic compounds. Mean steroid hormone concentrations and percent oocyte atresia were not anomalous in pike from any YRB site. Few site differences were significant for mean MA density (1.86 to 6.42 MA/mm2), size (812 to 1481 μm2), and tissue occupied (MA-%; 0.24% to 0.75%). A linear regression between MA-% and total PCBs was significant, although PCB concentrations were generally low in YRB pike (≤63 ng/g), and MA-% values in female pike (0.24% to 0.54%) were lower than in male pike (0.32% to 0.75%) at similar PCB concentrations. Greater numbers of MAs were found as zinc concentrations increased in YRB female pike, but it is unlikely that this is a causative relationship. Histological abnormalities observed in gill, liver, spleen, and kidney tissues were not likely a result of contaminant exposure but provide information on the general health of YRB pike. The most common histologic anomalies were parasitic infestations in various organs and developing nephrons and nephrocalcinosis in posterior kidney tissues. Overall, few biomarker responses in YRB pike were correlated with chemical contaminant concentrations, and YRB pike generally appeared to be healthy with no site having multiple anomalous biomarker responses.
PCBs and PCDD/FS in Fish and Fish Products and Their Impact on the Human Body Burden in Belgium by W. Baeyens; M. Leermakers; M. Elskens; N. Van Larebeke; R. De Bont; H. Vanderperren; A. Fontaine; J.-M. Degroodt; L. Goeyens; V. Hanot; I. Windal (pp. 563-571).
The concentrations of marker PCBs (28, 52, 101, 118, 138, 153, 180) in fish have been assessed with GC-MS: an average concentration of 540 ng-PCB g−1 fat (5.02 ng-PCB g−1 wet weight) was observed. The average concentration of PCDD/Fs, assessed with the CALUX bioassay, amounted to 64 pg-CALUX-TEQ g−1 fat (0.58 pg-CALUX-TEQ g−1 wet weight) and that of PCDD/Fs + dioxin-like PCBs amounted to 131 pg-CALUX-TEQ g−1 fat (1.18 pg-CALUX-TEQ g−1 wet weight). Results of the PCB congeners analyses show that PCB-153 is the most abundant congener in almost all samples, with also main contributions of the 138- and 180-congeners. For some species such as the sand sole and lemon sole, a fairly constant PCB content, independent of the fat percentage, was observed. For a second group of species such as whelks, cod, and whiting, a positive correlation was observed between their PCB concentration (ng g−1 fat) and their % of fat. The relationship between marker PCBs and PCDD/Fs concentrations, when plotted on a log scale, fits a straight line (correlation coefficient r = 0.83). With our results on fish and literature data for other food products, intake of marker PCBs and PCDD/Fs could be calculated for the adult population in Belgium (19–60 years old). The Total Daily Intake (TDI) of marker PCBs (ng-PCB day−1) ranges between 1690 and 2210. The TDI of PCDD/Fs (pg-CALUX day−1) ranges between 80.5 and 122, that of PCDD/Fs + dioxin-like PCBs amounts to 151. When PCDD/Fs in fish are assessed with GC-HRMS, the TDI can be lower. The relative importance of fish regarding marker PCB intake amounts to 15–19%, while regarding PCDD/Fs intake it amounts to 34–51%. Using TDI, the body burden evolution of marker PCBs and PCDD/Fs, with age has been calculated.
Trophic Transfer of Polychlorinated Biphenyls in Great Blue Heron (Ardea herodias) at Crab Orchard National Wildlife Refuge, Illinois, United States by C. L. Straub; J. D. Maul; R. S. Halbrook; B. Spears; M. J. Lydy (pp. 572-579).
In this study, polychlorinated biphenyl (PCB) concentrations were measured in great blue heron (GBHE) (Ardea herodias) chicks and eggs at Crab Orchard National Wildlife Refuge (CONWR) in southern Illinois. In addition, biomagnification factors (BMFs) from gizzard shad (Dorosoma cepedianum) and their effects on reproductive effort were examined. Total PCBs (ΣPCBs) in chicks and shad were greater at the east end of Crab Orchard Lake (i.e., near the site of contamination) than the west end, but chick concentrations (4.1 to 10.1 mg/kg lipid weight) were lower than those typically associated with adverse effects. Chick BMFs based on shad from diet samples were greater than those based on shad collected from the lake. Furthermore, the two shad sources had dissimilar dioxin-like congener patterns and ΣPCBs, suggesting that there was variation in PCB load and composition and that the more contaminated shad were a small proportion of the actual heron chick diet. The number of eggs laid per nest was similar between colonies, suggesting no observable population level effects. Further study may be necessary to evaluate long-term effects on GBHEs at CONWR.
Contaminants in Lesser and Greater Scaup Staging on the Lower Great Lakes by S. A. Petrie; S. S. Badzinski; K. G. Drouillard (pp. 580-589).
The decrease and subsequent lack of recovery of the North American scaup population has increased concerns about contaminants acquired during migration. We collected 189 fall- and spring-migrant lesser (Aythya affinis) and greater scaup (A. marila) on the lower Great Lakes (LGL) to determine if organic contaminants and trace elements in scaup livers were increased and to evaluate sources of variation in selenium (Se) burdens. We found that all organic contaminants were below toxic levels. Of 18 trace elements, only Se was detected at increased (>10-ppm dry-mass) levels. Se in lesser scaup increased but remained constant in greater scaup throughout fall; levels were increased in 14% of lesser scaup and 46% of greater scaup. During spring, Se increased in lesser scaup but decreased slightly in greater scaup; levels were increased in 75% of lesser scaup and 93% of greater scaup. We suggest that Se may be problematic for some breeding female scaup after departing the LGL, but more research is needed to determine the extent to which it affects scaup demographics.
Suppression of Endogenous Antioxidant Enzymes by 2,3,7,8-Tetrachlorodibenzo-p-dioxin–Induced Oxidative Stress in Chicken Liver During Development by J. Lim; J. C. DeWitt; R. A. Sanders; J. B. Watkins III; D. S. Henshel (pp. 590-595).
Domestic chickens (Gallus gallus) are an excellent model in which to evaluate developmental toxicity and oxidative stress because of their high sensitivity to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The goal of this study was to measure the effects of environmentally relevant doses of TCDD on endogenous hepatic antioxidant enzyme activity in hatchling chickens. The vehicle (sunflower oil) or 2, 20, or 200 pg/g TCDD was injected into chicken eggs before incubation. On hatching, livers were harvested and quickly frozen. The changes in activity of antioxidant enzymes, including glutathione peroxidase (GPx), glutathione reductase (GRx), copper zinc superoxide dismutase (SOD), and catalase (CAT) were determined as indicators of oxidative stress. TCDD exposure was associated with a significant suppression of the activities of the protective endogenous enzymes GPx, GRx, and SOD in the liver, even at the lowest dose. CAT activity was also suppressed, but not significantly. The measured decreases were 37% to 63% for GPx, 50% to 58% for GRx, 30% to 40% for SOD, and 16% to 24% for CAT. Noncomplex dose–response relationships were evident in GPx and GRx, whereas SOD and CAT curves were U-shaped. These results demonstrate that a decreased ability to scavenge reactive oxygen species may result from developmental TCDD exposure at very low doses, contributing to oxidative stress and thus to the embryotoxicity of TCDD.
New Analysis of a Rat Feeding Study with a Genetically Modified Maize Reveals Signs of Hepatorenal Toxicity by Gilles-Eric Séralini; Dominique Cellier; Joël Spiroux de Vendomois (pp. 596-602).
Health risk assessment of genetically modified organisms (GMOs) cultivated for food or feed is under debate throughout the world, and very little data have been published on mid- or long-term toxicological studies with mammals. One of these studies performed under the responsibility of Monsanto Company with a transgenic corn MON863 has been subjected to questions from regulatory reviewers in Europe, where it was finally approved in 2005. This necessitated a new assessment of kidney pathological findings, and the results remained controversial. An Appeal Court action in Germany (Münster) allowed public access in June 2005 to all the crude data from this 90-day rat-feeding study. We independently re-analyzed these data. Appropriate statistics were added, such as a multivariate analysis of the growth curves, and for biochemical parameters comparisons between GMO-treated rats and the controls fed with an equivalent normal diet, and separately with six reference diets with different compositions. We observed that after the consumption of MON863, rats showed slight but dose-related significant variations in growth for both sexes, resulting in 3.3% decrease in weight for males and 3.7% increase for females. Chemistry measurements reveal signs of hepatorenal toxicity, marked also by differential sensitivities in males and females. Triglycerides increased by 24–40% in females (either at week 14, dose 11% or at week 5, dose 33%, respectively); urine phosphorus and sodium excretions diminished in males by 31–35% (week 14, dose 33%) for the most important results significantly linked to the treatment in comparison to seven diets tested. Longer experiments are essential in order to indicate the real nature and extent of the possible pathology; with the present data it cannot be concluded that GM corn MON863 is a safe product.
Heavy-Metal Concentrations in Small Mammals from a Diffusely Polluted Floodplain: Importance of Species- and Location-Specific Characteristics by S. Wijnhoven; R. S. E. W. Leuven; G. van der Velde; G. Jungheim; E. I. Koelemij; F. T. de Vries; H. J. P. Eijsackers; A. J. M. Smits (pp. 603-613).
The soil of several floodplain areas along large European rivers shows increased levels of heavy metals as a relict from past sedimentation of contaminants. These levels may pose risks of accumulation in food webs and toxicologic effects on flora and fauna. However, for floodplains, data on heavy-metal concentrations in vertebrates are scarce. Moreover, these environments are characterised by periodical flooding cycles influencing ecologic processes and patterns. To investigate whether the suggested differences in accumulation risks for insectivores and carnivores, omnivores, and herbivores are reflected in the actual heavy-metal concentrations in the species, we measured the current levels of Zn, Cu, Pb, and Cd in 199 specimens of 7 small mammal species (voles, mice, and shrews) and in their habitats in a diffusely polluted floodplain. The highest metal concentrations were found in the insectivorous and carnivorous shrew, Sorex araneus. Significant differences between the other shrew species, Crocidura russula, and the vole and mouse species was only found for Cd. The Cu concentration in Clethrionomys glareolus, however, was significantly higher than in several other vole and mouse species. To explain the metal concentrations found in the specimens, we related them to environmental variables at the trapping locations and to certain characteristics of the mammals. Variables taken into account were soil total and CaCl2-extractable metal concentrations at the trapping locations; whether locations were flooded or nonflooded; the trapping season; and the life stage; sex; and fresh weight of the specimens. Correlations between body and soil concentrations and location or specimen characteristics were weak. Therefore; we assumed that exposure of small mammals to heavy-metal contamination in floodplains is significantly influenced by exposure time, which is age related, as well as by dispersal and changes in foraging and feeding patterns under influence of periodic flooding.