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Archives of Environmental Contamination and Toxicology (v.55, #3)
Pollution, Contamination and Future Land Use at Brookhaven National Laboratory by J. Burger; M. Gochfeld; S. Shukla; C. Jeitner; R. Ramos; Nellie Tsipoura; M. Donio (pp. 341-347).
Scientists interested in contamination normally deal only with pollution itself, not with people’s perceptions of pollution or the relationship between pollution and land use. The overall objective of this article was to examine the relationship between people’s perceptions of pollution and their views on future land use. People were interviewed at an Earth Day Festival near the Department of Energy’s Brookhaven National Laboratory (BNL) on Long Island, New York. On an open-ended question, people thought that BNL should be left as it is, or maintained as a preserve, park or conservation area, or used for environmental research. Almost no one thought that it should be used for housing or industrial purposes. When asked to rate a list of possible future land uses, maintaining BNL as a National Environmental Research Park for research and for recreation were rated the highest (nuclear storage was rated the lowest). This was consistent with the subjects’ views that pollution was the greatest concern about BNL. The congruence between perceptions about concerns or problems and future land use preferences suggests a unified view of management of contaminated sites, such as BNL, at least among a group of people whose environmental interests were evident by their presence at the event.
The Effects of Microbial Materials Adhered to Asian Sand Dust on Allergic Lung Inflammation by T. Ichinose; S. Yoshida; K. Hiyoshi; K. Sadakane; H. Takano; M. Nishikawa; I. Mori; R. Yanagisawa; H. Kawazato; A. Yasuda; T. Shibamoto (pp. 348-357).
Asian sand dust (ASD) containing microbiological materials, sulfate (SO 4 2 ), and nitrate (NO 3 − ) derived from air pollutants in East China, reportedly cause adverse respiratory health effects. ASD aggravates ovalbumin (OVA)-associated experimental lung eosinophilia. In this study, the toxic materials adsorbed onto ASD were excluded by heat treatment at 360°C for 30 min. The effects of nonheated ASD or heated ASD (H-ASD) toward the allergic lung inflammation were compared in murine lungs. ICR mice were administered intratracheally with normal saline (control), H-ASD, ASD, OVA, OVA + H-ASD, and OVA + ASD, four times at 2-week intervals. ASD only increased neutrophils in bronchoalveolar lavage fluids (BALFs) along with pro-inflammatory mediators, such as keratinocyte chemoattractant (KC). H-ASD and ASD enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. The two ASDs synergistically increased interleukin-5 (IL-5), monocyte chemotactic protein-3 (MCP-3), and eotaxin, which were associated with OVA, in BALF. The enhancing effects were much greater in ASD than in H-ASD. The two ASDs induced the adjuvant effects to specific IgE and IgG1 production by OVA. In the in vitro study using RAW264.7 cells, ASD increased the expression of Toll-like receptor 2 (TLR 2) mRNA but not TLR4 mRNA. H-ASD caused no expression of either TLR mRNA. These results suggest that the aggravated lung eosinophilia by ASD may be due to activation of Th2-associated immune response via the activation of TLR2 by microbial components adhered to ASD.
Organochlorine Pesticide Residues in Sediment Cores of Sunderban Wetland, Northeastern Part of Bay of Bengal, India, and Their Ecotoxicological Significance by S. K. Sarkar; A. Binelli; C. Riva; M. Parolini; M. Chatterjee; A. K. Bhattacharya; B. D. Bhattacharya; K. K. Satpathy (pp. 358-371).
This paper presents the first comprehensive report of the organochlorine pesticide residues (OCs) such as hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane and its six metabolites (DDTs), and hexachlorobenzene (HCB) in core sediments (<63-μm particle size) from the Indian Sunderban wetland. The pooled mean values of the mass fraction of ΣHCHs, HCB, and ΣDDTs in the sediments were 0.05–12, 0.05–1.4, and 0.05–11.5 ng g−1 dry weight, respectively. The vertical distribution of pesticides reveals an erratic pattern. The concentration of four isomers of HCHs reveals a heterogenic distribution where γ-HCH (lindane) and β-HCH shared the dominant part. The mass fraction of HCB did not show any sharp spatial variation. The prevailing sequence of DDT metabolites indicates an active degradation of the parent compound in the sediments and/or inputs of already degraded pp’DDT to the region. Peak concentrations of HCH isomers and DDT metabolites have the potential to induce ecotoxicological impact as per the sediment quality guidelines.
Effects of Deposition of Heavy-Metal-Polluted Harbor Mud on Microbial Diversity and Metal Resistance in Sandy Marine Sediments by Ann-Charlotte M. Toes; Niko Finke; J. Gijs Kuenen; Gerard Muyzer (pp. 372-385).
Deposition of dredged harbor sediments in relatively undisturbed ecosystems is often considered a viable option for confinement of pollutants and possible natural attenuation. This study investigated the effects of deposition of heavy-metal-polluted sludge on the microbial diversity of sandy sediments during 12 months of mesocosm incubation. Geochemical analyses showed an initial increase in pore-water metal concentrations, which subsided after 3 months of incubation. No influence of the deposited sediment was observed in denaturing gradient gel electrophoresis (DGGE) profiles of bacterial 16S rRNA genes, whereas a minor, transient impact on the archaeal community was revealed. Phylogenetic analyses of bacterial 16S rRNA clone libraries showed an abundance of members of the Flavobacteriaceae, the α- and γ-Proteobacteria, in both the muddy and the sandy sediments. Despite the finding that some groups of clones were shared between the metal-impacted sandy sediment and the harbor control, comparative analyses showed that the two sediments were significantly different in community composition. Consequences of redeposition of metal-polluted sediment were primarily underlined with cultivation-dependent techniques. Toxicity tests showed that the percentage of Cd- and Cu-tolerant aerobic heterotrophs was highest among isolates from the sandy sediment with metal-polluted mud on top.
A Factor Influence Study of Trace Element Bioaccumulation in Moss Bags by M. Cesa; B. Campisi; A. Bizzotto; C. Ferraro; F. Fumagalli; P. L. Nimis (pp. 386-396).
Moss bags of Rhynchostegium riparioides were exposed to different water concentrations of 11 trace elements under laboratory conditions, according to a saturated fractional factorial design (67 treated combinations), with the aim of measuring (1) element uptake and (2) the main effects and first-order interactions of influent factors. Bioaccumulation was directly proportional to water concentration, but the uptake ratio (ranging from 102 to 105) also depended on the concentration of other metals. The highest uptake ratios were observed for Al, Cu, Cr, Hg, and Pb. The multiple regression model showed that interactions among elements exist and induce both antagonism (Fe is the most frequent competitor) and synergism (Cr exerts a great influence on Pb and Zn uptake). Interactions might be relatively strong (as for As, Cr, and Pb) or weak (Cd and Hg). This evidence should be taken into consideration in biomonitoring surveys of industrial sites, where effluents release more than one contaminant.
Barium Toxicity Effects in Soybean Plants by Ryuichi Suwa; Krish Jayachandran; Nguyen Tran Nguyen; Abdellah Boulenouar; Kounosuke Fujita; Hirofumi Saneoka (pp. 397-403).
Barium (Ba)-induced phytotoxicity at 100, 1000, or 5000 μM Ba in soybean plants (Glycine max) was investigated under hydroponic culture conditions. Soybean growth and leaf photosynthetic activity were significantly inhibited by all three levels of Ba treatments. In the case of photosynthetic activity, 5000 μM Ba treatment shutdown stomatal opening and perturbed carbon fixation metabolism and translocation. However, 100 and 1000 μM Ba treatments shut down stomatal opening and inhibited carbon fixation, but without perturbation of leaf carbon fixation-related metabolism. Potassium (K) absorption by soybean roots was also reduced in all three Ba treatments. This decreased K absorption reduced K localization at guard cells. Barium accumulation in guard cells also inhibited K transport from epidermal cells to guard cells. This lack of K in guard cells resulted in stomatal closure. As a result of inhibition of K transport into guard cells and stomatal shutdown, photosynthetic activity and plant productivity were inhibited. Our experiment indicates that Ba has phytotoxic effects on soybean plants by inhibiting photosynthesis.
The Effects of Tannery Wastewater on the Development of Different Plant Species and Chromium Accumulation in Phragmites australis by Cristina S. C. Calheiros; António O. S. S. Rangel; Paula M. L. Castro (pp. 404-414).
Toxicity tests were performed to assess the effect of tannery wastewater with different treatment levels on two wetland plants, Phragmites australis and Typha latifolia, which are frequently used in constructed wetlands (CWs) for water treatment, and thus deepen the knowledge on their capacity to withstand the application of industrial wastewater. Trifolium pratense, a plant generally used as an indicator in toxicity tests, was included as a control. End points measured were germination percentage, shoot length, root elongation, and biomass growth of the plants. When tannery effluent, with a low treatment level, was supplied to the wetland plants germination occurred even at effluent concentrations of 100%, whereas germination of T. pratense was completely inhibited, almost invariably, at effluent concentration of 50%. Higher germination levels were achieved when the plants were exposed to effluent originating from the outlet of constructed wetland pilot units, allowing germination of all tested plants, indicating a significant decrease in its toxicity level. Experiments conducted with the same plants using different growing substrata as the germination matrix, namely expanded clay aggregates (Filtralite® MR 3-8 and Filtralite® NR 3-8) and two types of sand (fine gravel and standard sand) have shown that higher germination levels were achieved in standard sand and that P. australis was the plant species showing higher germination in all cases, reinforcing the robustness of this plant to environmental stress. The phytoextraction potential of P. australis, was evaluated by subjecting the plant to tannery wastewater supplemented with 50 and 150 mg Cr/L. After 6 weeks of exposure, levels up to 4825, 883, and 627 mg Cr/kg were found in the rhizome, shoot, and leaves, respectively, although phytotoxic signs in the plant were evident. This plant might not be considered a chromium hyperacumulator, but the potential to extract and accumulate this metal on its rhizomes is high.
Keywords: Toxicity; Tannery wastewater; Chromium; Constructed wetlands; Phragmites australis
Assessment of Potential Aquatic Herbicide Impacts to California Aquatic Ecosystems by Geoffrey S. Siemering; Jennifer D. Hayworth; Ben K. Greenfield (pp. 415-431).
A series of legal decisions culminated in 2002 with the California State Water Resources Control Board funding the San Francisco Estuary Institute to develop and implement a 3-year monitoring program to determine the potential environmental impacts of aquatic herbicide applications. The monitoring program was intended to investigate the behavior of all aquatic pesticides in use in California, to determine potential impacts in a wide range of water-body types receiving applications, and to help regulators determine where to direct future resources. A tiered monitoring approach was developed to achieve a balance between program goals and what was practically achievable within the project time and budget constraints. Water, sediment, and biota were collected under “worst-case” scenarios in close association with herbicide applications. Applications of acrolein, copper sulfate, chelated copper, diquat dibromide, glyphosate, fluridone, triclopyr, and 2,4-D were monitored. A range of chemical analyses, toxicity tests, and bioassessments were conducted. At each site, risk quotients were calculated to determine potential impacts. For sediment-partitioning herbicides, sediment quality triad analysis was performed. Worst-case scenario monitoring and special studies showed limited short-term and no long-term toxicity directly attributable to aquatic herbicide applications. Risk quotient calculations called for additional risk characterizations; these included limited assessments for glyphosate and fluridone and more extensive risk assessments for diquat dibromide, chelated copper products, and copper sulfate. Use of surfactants in conjunction with aquatic herbicides was positively associated with greater ecosystem impacts. Results therefore warrant full risk characterization for all adjuvant compounds.
Considerations for Assessments of Wadable Drainage Systems in the Agriculturally Dominated Deltas of Arkansas and Mississippi by W. W. Stephens; M. T. Moore; J. L. Farris; J. L. Bouldin; C. M. Cooper (pp. 432-441).
The watershed approach, currently used to assess regional streams in the United States, emphasizes least-disturbed reference conditions. Consideration of extensive wadable drainage systems found in Arkansas and Mississippi deltas challenges concepts of disturbance within a landscape of historic agricultural land use. Seventeen wadable drainage ditch sites in Arkansas and Mississippi deltas were characterized using water quality parameters and rapid bioassessment protocols. In all, 19 fish and 105 macroinvertebrate taxa were identified. Macroinvertebrate assemblages were dominated by coleopteran, dipteran, and hemipteran taxa at most drainage sites. Predominance of mobile, early colonists in ditches limits applicability of some metrics for assessment of stream integrity beyond prevalent conditions of ephemeral water quantity and habitat maintenance. This study provides evidence of considerable variability of physical characteristics, water quality, and fish and invertebrate metrics in wadable drainage systems. It indicates a disparity in usefulness of the watershed approach, emphasizing least-disturbed reference conditions, in assessing ecological integrity for a region with ditches as dominant landscape features.
Heavy Metal Levels in Suspended Sediments, Crassostrea gigas, and the Risk to Humans by Joline R. Widmeyer; Leah I. Bendell-Young (pp. 442-450).
Wild Pacific oyster (Crassostrea gigas) and sediment, both resuspended and suspended (RSS) samples (<53 μm), were collected over an 8-month period from a coastal estuary in Baynes Sound, BC, Canada. Stable isotope analysis (δ13C, δ15N) was used to determine, first, if RSS sediments was an important dietary source to C. gigas and, second, if so, whether it served as a significant dietary exposure route for Cd, Cu, Pb, and Zn. Although RSS sediments were high in trace metals such as Cd, Pb, Zn, and notably Cu, stable isotope signatures for oyster tissues did not correspond to those of RSS sediments. These results indicate that RSS sediments are not a significant source of metal to the oysters. In addition, we compared the potential risk to humans ingesting C. gigas with levels of Cd, Cu, Pb, and Zn from this study to the current Agency for Toxic Substances and Disease Registry (ATSDR) chronic oral minimal risk levels (MRLs) using current Canadian consumption guidelines of three oysters/week. Cu, Pb, and Zn levels were below MRL levels, with Cd exceeding the recommended 0.2 μg/kg/day MRL level fourfold. Total daily intake levels (TDI) for Cd were additionally calculated and either reached or exceeded the Food and Agriculture Organization/World Health Organization (FAP/WHO) reference dose of 1 μg/kg/day for Cd consumption in Canadians. Our results indicate that the current Canadian Cd consumption guidelines do not protect individuals consuming the maximum recommended levels of wild oysters.
The Accumulation of Lead and Mercury from Seawater and Their Depuration by Eggs of the Spotted Dogfish Scyliorhinus canicula (Chondrichthys) by R. A. Jeffree; F. Oberhansli; J.-L. Teyssie (pp. 451-461).
Radiotracer experiments using 210Pb and 203Hg demonstrated that eggs of the spotted dogfish Scyliorhinus canicula absorbed lead and inorganic mercury directly from seawater over 21 days of experimental exposure, attaining total egg concentration factors (CFs) relative to water of approximately 400 for Pb and 180 for Hg, predominantly (≥98%) due to their accumulation by the collagenous egg case. The rates of accumulation of both Pb and Hg by the total egg were significantly (P < 0.0001) reduced by its increasing age since parturition, whereas only the rate of depuration of Pb was reduced (P < 0.0001) with increasing age; these effects indicate a declining chemical reactivity of the egg case that may be due to the continued tanning of the case following parturition. The egg case per se, attained average CFs of about 1,500 and 850 for Pb and Hg, respectively. Both Pb and Hg showed declining concentration gradients from the exterior to the interior membranes of the wall of the egg case; CFs for Pb declined from 3,500 to 2,000 and for Hg from 5,000 to 500. Comparison of concentrations in separate membranes also demonstrated significant (P ≤ 0.01) depurations of Hg from the external and internal membranes during the loss experiments. The presence of radiotracers of Pb and Hg in the internal components of the egg at the end of uptake phase, and prior to the opening of the apertures, confirmed the permeability of the egg case wall to them, consistent with their observed gradients in it. The average CFs for all embryos at the end of the uptake experiment were 34 and 44 for Pb and Hg, respectively, but were significantly (P < 0.001) enhanced for Hg by a factor of 6 in the older eggs. The accumulatory and kinetic characteristics of the egg-case may operate to optimize the exposure of embryos to Pb and Hg following episodic contaminant events in coastal habitats.
Bee Honey as an Environmental Bioindicator of Pesticides’ Occurrence in Six Agricultural Areas of Greece by George Balayiannis; Panos Balayiannis (pp. 462-470).
The pollution of six agricultural areas of Greece (north, central, south) by insecticides used in crop protection has been investigated utilizing, as a bioindicator, bee honey produced in those areas. Honey samples collected randomly from apiaries located in those areas were analyzed for pesticide residues with a multianalytical method, able to determine simultaneously up to 10 organophosphorous insecticides from the same honey extract. Findings concerning the acaricide coumaphos were also included, even though it is not used in crop protection. Coumaphos is used to control the mite Varroa destructor, an external parasite of the honeybee. The above areas are cultivated in large extent with citrus trees or cotton or sunflower crops, which are good forages for honeybees. The main pests of those crops are insects; hence, insecticides are used on a large scale for crop protection. The most contaminated samples originated from citrus groves; 16 out of 19 had pesticide residues: 4 samples had chlorfenvinphos (21.05%), 10 had chlorpyrifos (52.63%) and 2 had phorate (10.53%). Out of 17 samples from cotton fields, residues were found in 8, phorate in 6 (35.29%), chlorfenvinphos in 1 (5.88%), and chlorpyrifos in 1 (5.88%). Out of nine samples from fields of sunflower, four had phorate residues (44.44%). In brief, from the 50 analyzed samples, residues of chlorfenvinphos were detected in 5 samples (10%), residues of chlorpyrifos in 11 samples (22%), and residues of phorate in 12 samples (24%). Their levels ranged between 0.70 and 0.89 μg/kg. Coumaphos residues ranged from 0.10 up to 4.80 μg/kg and were derived exclusively from beehives treated with Perizin (the commercial formulation of coumaphos) for Varroa control.This study indicates that in agricultural areas with developed apiculture, useful information about the occurrence and the distribution of pesticide residues due to crop protection treatments can be derived from the analysis of randomly collected honey samples, used as bioindicators. It also shows that, very often, the chemicals used by apiculturists inside the hives in order to control disease are the main pollutants of the produced honey.
Organochlorine Contamination in Anuran Amphibians of an Artificial Lake in the Semiarid Midwest of Argentina by Mariana B. Jofré; Rosa I. Antón; Enrique Caviedes-Vidal (pp. 471-480).
Artificial water reservoirs are important for fauna in arid-semiarid regions, because they provide suitable habitats for species that depend on water, such as amphibians. Organochlorine pesticides (OCPs) are toxic, persistent compounds that tend to bioaccumulate and bioconcentrate. We evaluated contaminant levels in anurans from an artificial lake (Embalse La Florida) in a semiarid region of the Midwest Argentina. This lake is one of the few sources of permanent water in the area. OCPs were detected in all individuals. Levels ranged from 2.34 ± 0.62 ng/g wet mass of heptachlors to 9.76 ± 1.76 ng/g wet mass of hexachlorocyclohexanes. The distribution pattern of OCP was ∑HCH > ∑DDT > endosulfan > ∑chlordane > metoxichlor > ∑aldrin > ∑heptachlor. Contaminant levels in individuals were positively correlated with contaminant levels in the water. Burden differed between species, but not among sites differing in water contaminant levels. Results suggest that anurans may concentrate OCPs and thus provide an important source of exposure for amphibian predators. This study provides important information for potential risk assessment of amphibians in the region and contributes to our understanding of the extent of OCP contamination.
Acute Toxicity and Tissue Distributions of Malathion in Ambystoma tigrinum by H. Henson-Ramsey; S. Kennedy-Stoskopf; J. F. Levine; S. K. Taylor; D. Shea; M. K. Stoskopf (pp. 481-487).
The kinetics of the bioaccumulation of malathion (O,O-dimethyl phosphorodithioate of diethyl mercaptosuccinate) and the biological impact of exposure for tiger salamanders, Ambystoma tigrinum, were assessed through exposure to soil surface contaminated with 50 μg/cm2 or 100 μg/cm2 malathion and ingestion of an earthworm exposed to soil contaminated with 200 μg/cm2 malathion. Malathion and malaoxon burdens in salamanders sampled at different times after exposure(s) were measured by gas chromatography in four tissue/organ subgroups: liver, epaxial muscle, pooled viscera (except the liver and brain), and pooled avisceral carcass (muscle, skin, and bone). The total tiger salamander xenobiotic burdens were calculated from these data. The malathion/malaoxon burden 1 day after exposure was greatest in the avisceral carcass and 2 days after exposure was greatest in the viscera. Bioconcentration and bioaccumulation factors remained less than unity throughout the experiment and did not support the hypothesis of bioaccumulation of malathion in the tiger salamander. Biological impact was assessed with a colorimetric brain cholinesterase microassay. Brain cholinesterase activities in salamanders exposed to malathion-contaminated soil (50 μg/cm2 or 100 μg/cm2 malathion) were suppressed ∼50–65% and 90%, respectively, compared to unexposed controls. The exposed animals did not exhibit overt clinical signs of malathion toxicosis.
Organochlorine Pollutants and Stable Isotopes in Resident and Migrant Passerine Birds from Northwest Michoacán, Mexico by Miguel A. Mora (pp. 488-495).
Although concentrations of organochlorine compounds (OCs) in birds from most of the United States and Canada have decreased over the last 30 years, there is still concern that migrant birds might be exposed to elevated concentrations of OCs during migration in Latin America. The Lerma-Chapala Basin in west-central Mexico is an important migration corridor and wintering area for many species. The objectives of this study were to assess if resident and migrant birds wintering in western Michoacán, Mexico accumulated elevated concentrations of OCs during fall and spring and to determine if the stable isotopes δ15N, δ13C, and δD could be used to predict burdens and origins of DDE accumulation. Resident and migrant passerine insectivorous birds were collected during fall and spring (2001–2002) in northwest Michoacán, near Chapala Lake, Mexico. The carcasses were analyzed for OCs and tail feathers were analyzed for stable isotopes δ15N, δ13C, and δD. The OCs detected in more than 50% of the samples were: oxychlordane (79%), p,p’-DDE (100%), p,p′-DDT (57%), and total PCBs (100%). p,p′-DDE was the OC detected at the highest concentrations, whereas residues of other OCs were near or below detection limits. Overall, there were no significant differences in concentrations of OCs between seasons or between resident and migrant birds. Concentrations of DDE and oxychlordane were somewhat higher in migrant and resident birds during spring than in fall; however, concentrations were significantly different only for oxychlordane. Two resident birds collected in fall and spring had DDE residues >10 μg/g wet weight in carcass. There were no significant differences in δ13C and δ15N values among species, between seasons, or between migrant and resident birds. However, δD values were clearly different between species and helped differentiate migrant from resident birds. δD values also were negatively and significantly correlated with DDE concentrations in carcass. Birds with more depleted δD values in feathers tended to have higher DDE concentrations than those with less depleted δD values, suggesting a potential latitudinal accumulation of DDE. Overall, our results suggest that during fall and spring, there is not a significant buildup of persistent OCs in migrant and resident passerine insectivorous birds in northwest Michoacán, Mexico.
Patterns and Trends of Chlorinated Hydrocarbons in Nestling Bald Eagle (Haliaeetus leucocephalus) Plasma in British Columbia and Southern California by Lillian S. Cesh; Tony D. Williams; David K. Garcelon; John E. Elliott (pp. 496-502).
Patterns and trends of chlorinated hydrocarbons were assessed in bald eagle nestling plasma from sites along the west coast of North America. Eagle plasma was sampled from four areas in southwestern British Columbia (BC), a reference site in northern BC, and from Santa Catalina Island, off the coast of California. Sites were chosen to reflect variation in contaminant exposure due to differing recent and/or historic anthropogenic activities. Santa Catalina Island had significantly greater mean concentrations of p,p′-DDE, 41.3 μg/kg wet weight (ww), than other sites, and Nanaimo/Crofton, BC had the greatest mean concentration of total PCBs, 28.9 μg/kg ww. Contaminant levels measured in 2003 in BC were compared to levels measured in 1993; over that ten year span, concentrations and patterns of chlorinated hydrocarbons have not significantly changed. There were no significant differences in levels of p,p′-DDE or hexachlorobenzene between 1993 and 2003, but significant decreases were found for trans-nonachlor and PCBs at BC sites. Levels of total PCBs and trans-nonachlor in the central Fraser Valley and Nanaimo/Crofton area have significantly decreased. Mean concentrations of p,p′-DDE measured in bald eagle nestling plasma samples in 2003 exceeded published criteria for effects on bald eagle reproduction at Santa Catalina Island and Barkley Sound, more than 30 years since heavy usage restrictions were imposed.
Toxic Element Concentration in the Atlantic Gannet Morus bassanus (Pelecaniformes, Sulidae) in Portugal by P. Mendes; C. Eira; J. Torres; A. M. V. M. Soares; P. Melo; J. Vingada (pp. 503-509).
The present study provides the first data on inorganic element levels in juvenile, subadult, and adult Atlantic gannets (Morus bassanus). Physiological and potentially toxic elements (As, Cd, Co, Cr, Cu, Hg, Mn, Pb, Se, and Zn) were assessed by ICP-MS in kidney, liver, muscle, and feathers of 31 gannets, including 18 juveniles, 7 subadults, and 6 adults. The effect of age and tissue on element accumulation was also assessed. Mercury was roughly above the minimum level for adverse effects in birds. A higher accumulation of Se and Cd was detected in kidney, Pb in feathers, and Mn in liver. Age was found to affect the accumulation of Cd, Co, Hg, Mn, Se, and Zn. Adults presented significantly lower levels of Mn, Se, and Zn than subadults. Linear positive relationships within tissues were detected involving Se-Cd and Se-Hg. Also, positive linear relationships were detected among kidney, liver, and muscle, with emphasis on relationships involving Cd, Hg, Se, and Zn, which may be indicative of analogous regulation mechanisms in those organs. Atlantic gannets occurring in the study area leave their reproduction sites as juveniles. During their development process, several molting cycles occur and thus the possible contamination risk by Hg should reflect levels in the development areas rather than contamination levels in reproduction areas. The present study provides basic information on multielement accumulation in Morus bassanus, which may help us to understand the behavior and toxicity of various elements in marine birds.
Enantiomeric Enrichment of 2,2′,3,3′,6,6′-Hexachlorobiphenyl (PCB 136) in Mice After Induction of CYP Enzymes by Izabela Kania-Korwel; Wei Xie; Keri C. Hornbuckle; Larry W. Robertson; Hans-Joachim Lehmler (pp. 510-517).
Several PCB congeners, present in commercial PCB formulations, are chiral. These PCBs can undergo enantiomeric enrichment in many animal species and in humans due to currently uncharacterized enantioselective biotransformation processes. To investigate if certain cytochrome P-450 enzymes (CYPs), such as CYP2B’s, are responsible for this enantiomeric enrichment, we investigated the enantioselective disposition of (±)-PCB 136 in female mice after induction of different CYP enzymes by pretreatment with corn oil alone, β-naphthoflavone (CYP1A’s), phenobarbital (CYP2B’s), or dexamethasone (2B’s and 3A’s), followed by oral PCB administration. PCB 136 levels were significantly lower in phenobarbital- and, to a lesser extent, in dexamethasone-pretreated animals, presumably due to the induction of PCB 136 metabolizing enzymes. Although (+)-PCB 136 was enriched in all tissues, none of the pretreatments altered the enantioselective disposition of PCB 136 in a manner that suggests a particular CYP subfamily as the cause of the enrichment of (+)-PCB 136. Fecal PCB levels and enantiomeric fraction values changed over time in a manner consistent with slower digestive motility in the mice pretreated with phenobarbital and dexamethasone. Overall, this study does not support the hypothesis that metabolism by CYP2B enzymes is responsible for the enrichment of (+)-PCB 136 in mice.
Subchronic Lead Feeding Study in Male Rats by Duane M. Smith Jr.; Howard W. Mielke; James B. Heneghan (pp. 518-528).
This study was done to establish baseline information on the bioavailability of low levels of different species of lead by oral feeding in young rats and to compare this with lead-contaminated soils of similar dosage. These results can be used to help establish low-level risk assessments for lead exposure in children. Lead acetate was used in this study as a point of reference because it was considered to be 100% bioavailable. The required amounts of either lead acetate or lead nitrate were added to the control soil of 135 mg/kg lead to match the targeted test soil lead concentrations of 375, 750, 1500, and 3000 mg/kg lead. This lead-contaminated soil was mixed 5% (soil/diet) by weight with a semipurified lab chow diet, which resulted in final dietary lead concentrations of 6.75, 18.75, 37.5, 75, and 150 μg Pb/g diet. Results from this study indicated that (1) the dietary lead concentrations used did not result in any overt signs of lead toxicity (i.e., no significant effect on body weight gain, food consumption, or fecal output), (2) there were significant dose-dependent increases in fecal lead concentration and total fecal lead output, although there were no significant differences among study groups, (3) there was a time-dependent decrease in net whole-body lead uptake from a total group average of 65% at week 1 down to ∼40% by week 5, and (4) there were no significant differences in terminal blood lead levels among study groups. Results from this study demonstrated a significant dose-dependent increase in tissue lead concentrations (μg Pb per g tissue weight) for bone, kidney, and liver for all study groups. There were no significant differences between the lead acetate and the test soil study groups at any lead dosages; however, there was a significantly increased lead incorporation into the bones from the lead nitrate study group. In summary, these results demonstrate that rats metabolize and handle lead of relatively small particle size from different soils and from different sources in a similar manner, although the use of lead acetate as the standard for 100% bioavailability might need to be reevaluated.
Nondestructive Scat Sampling in Assessment of Mink (Mustela vison) Exposed to Polychlorinated Dibenzofurans (PCDFs) by Matthew J. Zwiernik; Jeremy N. Moore; Jong Seong Khim; Lisa L. Williams; Denise P. Kay; Steve Bursian; Lesa L. Aylward; John P. Giesy (pp. 529-537).
The mink (Mustela vison) is often utilized as a sentinel species for ecological assessments at sites where contaminants of concern include dioxins and dioxin-like compounds. Utilizing mink scat as a nondestructive tool to determine internal exposure to dioxin-like compounds may allow for rapid, accurate estimates of exposure without the need to capture mink or their prey. To determine the relationships between concentrations of polychlorinated dibenzofurans (PCDFs) in tissues (liver and adipose) and those in scat, mink were fed PCDFs in scat during a controlled laboratory study for 180 days. Mink were fed a control diet, diets with three doses of 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PeCDF) or 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF), and a diet with an environmentally relevant mixture of the two congeners. Concentrations of PCDFs in liver and adipose were measured after 0, 90, and 180 days of exposure. Concentrations of the two PCDF congeners in mink scat were determined after 2, 23, 45, 90, and 180 days of exposure. Concentrations of both PCDF congeners in scat were significantly correlated with those in liver and adipose tissue (r 2 = 0.94−0.97, p < 0.01). This indicates that measurements of concentrations of both PCDFs in scat can be used to predict concentrations of PCDFs in liver and adipose. Assimilation and elimination characteristics of 2,3,4,7,8-PeCDF or 2,3,7,8,-TCDF and a mixture of the two congeners by mink could be predicted from concentrations of these congeners in scat. Overall, concentrations of PCDFs in mink scat can be used as a rapid and inexpensive nondestructive method to predict concentrations of PCDFs in mink when certain assumptions are met.
Human Exposure to Metals in Groundwater Affected by Acid Sulfate Soil Disturbance by A. Hinwood; P. Horwitz; R. Rogan (pp. 538-545).
The disturbance and oxidation of sulfidic soils can cause an increase in acidity resulting in the mobilization of high concentrations of metals in groundwater or connected surface water. This is an increasing problem in urban areas of Australia and internationally. We hypothesized that the risks of exposure to contaminated water would be increased by this phenomenon. We undertook a preliminary investigation of human exposure to metals recruiting 27 residents in an acid sulfate soil-affected area, 21 residents using a bore (groundwater) for home-grown produce irrigation, and 6 residents who did not. Participants completed a questionnaire and provided a sample of urine (first morning void), toenails (from all 10 toes), hair, and borewater. Only hair metal concentrations were higher in those using bore water and ranged from below detection (
Heavy Metal Concentrations in Feathers of Korean Shorebirds
by Jungsoo Kim; Tae-Hoe Koo (pp. 546-546).