Polychlorinated Biphenyls (polychlorinated + biphenyl)

Distribution by Scientific Domains

Kinds of Polychlorinated Biphenyls

  • dioxin-like polychlorinated biphenyl


  • Selected Abstracts


    Patterns of organic contaminants in eggs of an insectivorous, an omnivorous, and a piscivorous bird nesting on the Hudson River, New York, USA

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2010
    Christine M. Custer
    Abstract Belted kingfisher (Ceryle alcyon), spotted sandpiper (Actitus macularia), and tree swallow (Tachycineta bicolor) eggs were collected in 2004 from the upper Hudson River, New York, USA. This area is one of the most polychlorinated biphenyl (PCB)-contaminated locations in North America. Multivariate analyses indicated among species differences in the concentration and composition of PCB congeners, polychlorinated dibenzo- p -dioxin (PCDD), and dibenzofuran (PCDF, PCDD-F when combined with PCDDs) congeners, and chlorinated pesticides. Total PCB concentrations followed the typical food chain biomagnification paradigm of higher concentrations in piscivorous bird eggs and lower concentrations in eggs of species that feed at lower trophic levels. Concentrations in the insectivorous swallows (geometric mean,=,6.8,µg/g wet wt) were approximately half the concentrations present in the piscivorous kingfisher (11.7,µg/g) or omnivorous sandpiper (12.6,µg/g). In contrast, PCB toxic equivalents (TEQs) were higher in swallows (1,790,pg/g wet wt) than in either kingfishers (776,pg/g) or sandpipers (881,pg/g). This difference can be mainly attributed to higher PCB77 concentrations in swallows relative to the other two species. Also contrary to the accepted food-chain paradigm, the sum of PCDD-F concentrations and the sum of their TEQs were higher in swallows than in either sandpipers or kingfishers. Metabolic pathway differences in the respective food chains of the three species probably accounted for the differences observed in PCB TEQ, total PCDD-F, and PCDD-F TEQ concentrations among species. Environ. Toxicol. Chem. 2010;29:2286,2296. © 2010 SETAC [source]


    Estrogenic effects of polychlorinated biphenyls and relation to cytochrome P4501A activity in the endangered goodeid fish Ameca splendens,

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2008
    Armando Vega-López
    Abstract The present study examines the relationships between cytochrome P4501A (CYP1A) activity and vitellogenin (VTG) induction in Ameca splendens elicited by a polychlorinated biphenyl (PCB) mixture. Ethoxyresorufin- O -deethylase (EROD) activity, mRNA levels of VTG, and VTG induction were evaluated in male and female fish exposed for 1, 2, 4, 8, and 16 d to a commercial PCB mixture. Polychlorinated biphenyls induced higher EROD in both sexes and this induction was higher in females than in males. Maximum EROD and VTG induction occurred on day 1 in females, while in males these maxima occurred on days 8 and 16. A correlation between EROD and VTG induction was found only in males (p < 0.001), and VTG induction was also higher in males than in females (p < 0.01). Exposure to PCBs elicited increases in VTG expression and induction over time in males, while in females these decreased at the end of the exposure period. Deficiencies in the feedback mechanisms of male A. splendens exposed in the wild to xenoestrogens such as PCBs have probably contributed to alter the sex ratio of wild populations of this species. [source]


    Influence of contamination by organochlorine pesticides and polychlorinated biphenyls on the breeding of the Spanish Imperial Eagle (Aquila adalberti)

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2008
    Mauro Hernández
    Abstract We evaluated temporal and regional trends of organochlorine (OC) pesticide (including polychlorinated biphenyl [PCB]) levels in eggs of the Spanish Imperial Eagle (Aquila adalberti) collected in Spain between 1972 and 2003. Levels of p,p,-dichlorodiphenyldichloroethylene (DDE) and PCBs varied significantly (p = 0.022) among regions (central, western, and Doñana), being higher in Doñana than in the central and western populations (DDE: 1.64 ± 5.56, 0.816 ± 1.70, and 1.1 ± 2.66 ,g/g, respectively; PCBs: 1.189 ± 5.0, 0.517 ± 1.55, and 0.578 ± 1.75 ,g/g, respectively). Levels of DDE decreased with time, but a significant interaction was observed between region and time. In Doñana, egg volume and breadth as well as Ratcliffe Index were significantly lower after DDT use (p = 0.0018) than during the pre-DDT period (p = 0.0018); eggs were significantly smaller overall than in the other two regions (p = 0.04) and were smaller when DDE levels increased, even when controlling for regional differences (p = 0.04). Productivity in Doñana was significantly lower than in the other regions (p < 0.001). Clutch size in Doñana varied according to DDE concentrations (p = 0.01), with the highest DDE concentrations found in clutches consisting of one egg. When considering eggs with DDE levels greater than 3.5 ,g/g, a significant effect of DDE on fertility was found (p = 0.03). Clutches with DDE levels greater than 4.0 ,g/g had a higher probability of hatching failure (p = 0.07) and produced fewer fledglings (p = 0.03). If we consider 3.5 ,g/g as the lowest-observable-adverse-effect level, the proportion of sampled clutches that exceeded that level in Doñana (29%) was significantly higher than in other regions (p < 0.001). These eggs showed a mean percentage of thinning of 16.72%. Contamination by OCs, mainly DDE, could explain, at least in part, the low productivity of the Spanish Imperial Eagles in Doñana. [source]


    Determination of polychlorinated biphenyl and polycyclic aromatic hydrocarbon elimination rates in adult green and leopard frogs

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2006
    Jocelyn L. Leney
    Abstract The purpose of the present study was to quantify elimination kinetics of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in adult green frogs (Rana clamitans) and leopard frogs (Rana pipiens). Three experiments were conducted: PCB elimination rate constants were determined for both frog species, and PAH elimination rate constants were determined for leopard frogs only. In green frogs, significant PCB elimination rate constants ranged from 0.013 to 0.04 d,1 (time for frogs to achieve 90% steady state with water [t90] = 57.8-178.2 d). In leopard frogs, significant PCB elimination rate constants ranged from 0.004 to 0.047 d,1 (t90 = 48.8-657.9 d). Polycyclic aromatic hydrocarbon elimination in leopard frogs was faster than PCB elimination in either frog species: Significant PAH rate constants ranged from 0.069 to 0.188 d,1 (t90 = 12.2-33.5 d). In both species, and for both PCBs and PAHs, a significant inverse relationship was found between the chemical elimination rate constant and Kow. These results show that adult anurans have relatively low elimination rates of PCBs but exhibit a small capacity for metabolic biotransformation of PAHs that is comparable to that of invertebrates but lower than that of fish. These findings suggest that adult amphibians have the potential to be used as biomonitors for persistent organic chemicals. [source]


    Ecological risk assessment of persistent toxic substances for the clam Tapes philipinarum in the lagoon of venice, italy

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2004
    Christian Micheletti
    Abstract Because of contamination of sediments of the Lagoon of Venice, Italy, by inorganic pollutants (e.g., arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc) and organic pollutants (e.g., polychlorobiphenyls), as well as the ecological and economical relevance of the edible clam Tapes philipinarum, an ecological risk assessment was undertaken to ascertain the extent of bioaccumulation that would pose a significant risk. Risk was estimated by means of toxic units and hazard quotient approaches, by comparing the exposure concentration with the effect concentration. Clam exposure was estimated by applying previous results based on bioaccumulation spatial regression models. In addition, a comparison was made between sum of dioxin-like polychlorinated biphenyl (PCB) congeners and total PCB bioaccumulation provided by spatial regression models and by a partitioning model. The effect concentrations were calculated as tissue screening concentrations, as the product of pollutant sediment quality criteria and the bioaccumulation factor. Finally, the cumulative risk posed by selected inorganic pollutants and total PCBs was estimated and a map of risk was drawn. The resulting chemicals of potential ecological concern were mercury, cadmium, arsenic, and nickel, as well as, to a lesser extent, total PCBs. [source]


    Harbor seals (Phoca vitulina) in British Columbia, Canada, and Washington State, USA, reveal a combination of local and global polychlorinated biphenyl, dioxin, and furan signals

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2004
    Peter S. Ross
    Abstract The harbor seal (Phoca vitulina) can serve as a useful indicator of food web contamination by persistent organic pollutants (POPs) because of its high trophic level, wide distribution in temperate coastal waters of the Northern Hemisphere, and relative ease of capture. In 1996 through 1997, we live-captured 60 harbor seal pups from three regions, spanning remote (Queen Charlotte Strait, BC, Canada), moderately industrialized (Strait of Georgia, BC, Canada), and heavily industrialized (Puget Sound, WA, USA) marine basins straddling the Canada-United States border. Biopsy samples of blubber were taken and analyzed for congener-specific polychlorinated biphenyls (PCBs), polychlorinated dibenzo- p -dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) by using high-resolution gas chromatography-high-resolution mass spectrometry. Harbor seals in Puget Sound were heavily contaminated with PCBs, whereas seals from the Strait of Georgia had relatively high concentrations of PCDDs and PCDFs. Pattern evaluation and principal components analysis suggested that proximity to sources influenced the mixture to which seals were exposed, with those inhabiting more remote areas being exposed to lighter PCB congeners (those with lower Henry's law constant and KOW) that disperse more readily through atmospheric and other processes. Total toxic equivalents to 2,3,7,8-tetrachlorodibenzo- p -dioxin for the PCBs, PCDDs, and PCDFs suggest that Puget Sound seals are at greatest risk for adverse health effects, and that PCBs represent the class of dioxinlike contaminants of greatest concern at all sites. [source]


    Hepatic microsomal cytochrome P450 enzyme activity in relation to in vitro metabolism/inhibition of polychlorinated biphenyls and testosterone in Baltic grey seal (Halichoerus grypus)

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2003
    Hongxia Li
    Abstract Among other factors, cytochrome P450 (CYP) enzyme activity determines polychlorinated biphenyl (PCB) bioaccu-mulation, biotransformation, and toxicity in exposed species. We measured the oxidative metabolism in vitro of 12 PCB congeners, representing structural groups based on the number and position of the chlorine atoms, by the hepatic microsomes of one Baltic grey seal (Halichoerus grypus). Microsomal metabolism was observed for several PCBs with vicinal H atoms exclusively in the ortho and meta positions and without any ortho -Cl substituents (CB-15 [4,4,-Cl2] and CB-77 [3,3,,4,4,-Cl4]), vicinal meta and para -H atoms (CB-52 [2,2,,5,5,-Cl4], and ,101 [2,2,,4,5,5,-Cl5]) or with both characteristics in combination with either only one ortho -Cl (CB-26 [2,3,,5-Cl3], CB-31 [2,4,,5-Cl3]) or two ortho -Cl substituents (CB-44 [2,2,,3,5,-Cl4]). To allocate PCB biotransformation to specific CYPs, the inhibitive effect of compounds with known CYP-specific inhibition properties was assessed on in vitro PCB metabolism and on regio- and stereospecific testosterone hydroxylase activities. Metabolic inhibition was considered relevant at concentrations ,1.0 ,M because these inhibitors became decreasingly selective at higher concentrations. At <1.0 ,M, ellipticine (CYP1A1/2 inhibitor) selectively inhibited CB-15, ,26, ,31, and ,77 metabolism, with no significant inhibition of CB-44, ,52, and ,101 metabolism. Inhibition of CB-52 and ,101 metabolism by chloramphenicol (CYP2B inhibitor) started at 1.0 ,M and maximized at about 100% at 10 ,M. Ketoconazole (CYP3A inhibitor) appeared to selectively inhibit CB-26, ,31, and ,44 metabolism relative to CB-15, ,77, and ,52 at concentrations ,1.0 ,M. Major testosterone metabolites formed in vitro were 2,-(CYP3A), 6,- (CYP3A, CYP1A), and 16,- (CYP2B) hydroxytestosterone and androstenedione (CYP2B, CYP2C11). The CYP forms indicated are associated with the specific metabolism of testosterone in laboratory animals. Inhibition of 2,- and 6,-hydroxytestosterone formation at ellipticine and ketoconazole concentrations ,1.0,M suggested that both inhibitors were good substrates of CYP3A-like enzymes in grey seal. Chloramphenicol (model for CYP2B) is apparently not a good inhibitor of CYP1A and CYP3A activities in grey seal because the chemical did not inhibit any metabolic route of testosterone at concentrations from 0.1 to 10 ,M. Our findings demonstrated that at least CYP1A- and CYP3A-like enzymes in the liver of grey seals are capable of metabolizing PCBs with ortho - meta and/or meta - para vicinal hydrogens. A CYP2B form might also be involved, but this could not be proven by the results of our experiments. Defining the profiles of CYP enzymes that are responsible for PCB biotransformation is necessary to fully understand the bioaccumulation, toxicokinetics, and risk of PCB exposure in seals and other free-ranging marine mammals. [source]


    Effects of pre- and postnatal polychlorinated biphenyl exposure on metabolic rate and thyroid hormones of white-footed mice,

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2001
    John B. French Jr.
    Abstract Energy budgets have proven to be a valuable tool for predicting life history from physiological data in terrestrial vertebrates, yet these concepts have not been applied to the physiological effects of contaminants. Contaminants might affect energy budgets by imposing an additional metabolic cost or by reducing the overall amount of energy taken in; either process will reduce the energy available for production (i.e., growth or reproduction). This study examined whole animal energetic effects of polychlorinated biphenyl (PCB) exposure in white-footed mice (Peromyscus leucopus). Exposure to PCBs is known to reduce concentrations of plasma thyroid hormones, and thyroid hormones exert strong control over the rate of energy metabolism in mammals. Peromyscus leucopus that were proven breeders were fed PCBs in their food at 0, 10, and 25 ppm. Through lactation, offspring were exposed to PCB from conception and were maintained on the maternal diet to adulthood. No effects were seen on energy metabolism (O2 consumption, measured in adulthood) or on growth, but there were large dose-dependent decreases in thyroid hormone concentrations, particularly T4. The apparent disparity in our data between unchanged metabolic rates and 50% reductions in T4 concentrations can be rationalized by noting that free T3 (the fraction not bound to plasma protein) in treated mice was not significantly different from controls and that metabolism is most strongly influenced by free T3. Overall, this study did not demonstrate any energetic consequences of PCB exposure in P. leucopus at dietary concentrations up to 25 ppm. [source]


    Bayesian uncertainty assessment in multicompartment deterministic simulation models for environmental risk assessment

    ENVIRONMETRICS, Issue 4 2003
    Samantha C. Bates
    Abstract We use a special case of Bayesian melding to make inference from deterministic models while accounting for uncertainty in the inputs to the model. The method uses all available information, based on both data and expert knowledge, and extends current methods of ,uncertainty analysis' by updating models using available data. We extend the methodology for use with sequential multicompartment models. We present an application of these methods to deterministic models for concentration of polychlorinated biphenyl (PCB) in soil and vegetables. The results are posterior distributions of concentration in soil and vegetables which account for all available evidence and uncertainty. Model uncertainty is not considered. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Initial investigation on the use of waterjets to place amendments in the subsurface

    REMEDIATION, Issue 1 2005
    John W. Cable
    Quasi-passive in situ remediation technologies, such as the use of permeable reactive barriers to treat contaminated groundwater or applications of granular activated carbon to treat polychlorinated biphenyl (PCB)-contaminated, near-surface sediments, are proven or promising technologies that may be limited in application due to the traditional construction techniques normally used for placement in the environment. High-pressure waterjets have traditionally been used to excavate material during mining operations or to cut rock or other durable material. Waterjets have the potential to place amendments in the subsurface at depths greater than those that can be obtained using traditional construction techniques. Likewise, waterjets may have less negative impact on near-surface utilities and/or sensitive ecological systems. Laboratory experiments were performed to characterize the placement of two solid amendments in a simulated saturated aquifer. A second set of experiments was performed to characterize the effectiveness of waterjets for placing a third amendment in simulated intertidal sediments. The laboratory work focused on characterizing the nature of the waterjet penetration of the aquifer matrix and the saturated sediments, as well as the corresponding waterjet parameters of pressure, nozzle size, and injection time. The laboratory results suggest that field trials may be appropriate for future investigations. © 2005 Wiley Periodicals, Inc. [source]


    Oxidative Stress Alters Creatine Kinase System in Serum and Brain Regions of Polychlorinated Biphenyl (Aroclor 1254)-Exposed Rats: Protective Role of Melatonin

    BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 2 2009
    Prabhu Venkataraman
    Creatine kinase plays a key role in energy metabolism of nervous tissue and might be one of the targets for reactive oxygen species. Melatonin, an indoleamine, plays an important role in neurodegenerative diseases as an antioxidant and neuroprotector. The objective of the present study was to investigate the protective role of melatonin on polychlorinated biphenyl (Aroclor 1254)-induced oxidative stress and the changes in creatine kinase activity in brain regions of adult rats. Group I: rats were intraperitoneally (i.p.) administered with corn oil (vehicle) for 30 days. Group II: rats injected i.p. with Aroclor 1254 at 2 mg/kg body weight (bw)/day for 30 days. Groups III and IV: rats i.p. received melatonin (5 or 10 mg/kg bw/day) simultaneously with Aroclor 1254 for 30 days. After 30 days, rats were killed and the brain regions were dissected to cerebral cortex, cerebellum and hippocampus. Lipid peroxidation, hydroxyl radical and hydrogen peroxide (H2O2) levels were determined. The activity of creatine kinase was assayed in serum and brain regions, and its isoenzymes in serum were separated electrophoretically. Activity of creatine kinase was decreased while an increase in H2O2, hydroxyl radical and lipid peroxidation was observed in brain regions of polychlorinated biphenyl-treated rats. Also polychlorinated biphenyl exposure showed a significant increase in serum creatine kinase level and its isoforms such as BB-creatine kinase, MB-creatine kinase, and MM-creatine kinase. Administration of melatonin prevented these alterations induced by polychlorinated biphenyl by its free radical scavenging mechanism. Thus, polychlorinated biphenyl alters creatine kinase activity by inducing oxidative stress in brain regions, which can be protected by melatonin. [source]


    Widespread capacity to metabolize polychlorinated biphenyls by diverse microbial communities in soils with no significant exposure to PCB contamination

    ENVIRONMENTAL MICROBIOLOGY, Issue 8 2007
    Alexandre J. Macedo
    Summary The purpose of this work was to determine the extent of microbial metabolic potential for polychlorinated biphenyls (PCBs) in soils that have had no previous exposure to this class of xenobiotic pollutants. Soil and sediment samples of distinct characteristics from six sites in Germany were used to inoculate PCB oil (Aroclor 1242) microdroplets. All samples yielded multispecies biofilms, as revealed by single-strand conformation polymorphism (SSCP) analyses of polymerase chain reaction (PCR) analysis of 16S rRNA genes, and sequence analysis of the main amplicons. Microbes representing 20 different operational taxonomic units (OTUs) were identified in the biofilms, but only a few were common to all biofilms, namely those closely related to Aquabacterium sp., Caulobacter sp., Imtechium assamiensis, Nevskia ramosa, Parvibaculum lavamentivorans and Burkholderia sp. The PCB biofilm communities were always distinct from control biofilms developing from the same samples in the absence of PCB. All PCB droplet-grown biofilms degraded multiple PCB congeners but differed in the congener spectra they degraded. These findings reveal that microbial potential to degrade PCBs is widespread in soils that have not been subjected to PCB contamination, and that this potential is characteristic of consortia of very diverse phylogenetic composition. [source]


    Bioreductive deposition of palladium (0) nanoparticles on Shewanella oneidensis with catalytic activity towards reductive dechlorination of polychlorinated biphenyls

    ENVIRONMENTAL MICROBIOLOGY, Issue 3 2005
    Wim De Windt
    Summary Microbial reduction of soluble Pd(II) by cells of Shewanella oneidensis MR-1 and of an autoaggregating mutant (COAG) resulted in precipitation of palladium Pd(0) nanoparticles on the cell wall and inside the periplasmic space (bioPd). As a result of biosorption and subsequent bioreduction of Pd(II) with H2, formate, lactate, pyruvate or ethanol as electron donors, recoveries higher than 90% of Pd associated with biomass could be obtained. The bioPd(0) nanoparticles thus obtained had the ability to reductively dehalogenate polychlorinated biphenyl (PCB) congeners in aqueous and sediment matrices. Bioreduction was observed in assays with concentrations up to 1000 mg Pd(II) l,1 with depletion of soluble Pd(II) of 77.4% and higher. More than 90% decrease of PCB 21 (2,3,4-chloro biphenyl) coupled to formation of its dechlorination products PCB 5 (2,3-chloro biphenyl) and PCB 1 (2-chloro biphenyl) was obtained at a concentration of 1 mg l,1 within 5 h at 28°C. Bioreductive precipitation of bioPd by S. oneidensis cells mixed with sediment samples contaminated with a mixture of PCB congeners, resulted in dechlorination of both highly and lightly chlorinated PCB congeners adsorbed to the contaminated sediment matrix within 48 h at 28°C. Fifty milligrams per litre of bioPd resulted in a catalytic activity that was comparable to 500 mg l,1 commercial Pd(0) powder. The high reactivity of 50 mg l,1 bioPd in the soil suspension was reflected in the reduction of the sum of seven most toxic PCBs to 27% of their initial concentration. [source]


    Interaction between halogenated aromatic compounds in the Ah receptor signal transduction pathway

    ENVIRONMENTAL TOXICOLOGY, Issue 5 2004
    Guosheng Chen
    Abstract Many toxic and biochemical responses to halogenated aromatic compounds (HACs) such as polychlorinated biphenyls (PCBs) and polychlorinated dibenzo- p -dioxins (PCDDs) are mediated through the aryl hydrocarbon receptor (AhR), which is an intracellular cytosolic target for HACs. Environmental exposure to HACs almost always involves complex mixtures of congeners, some of which can antagonize the action of potent HACs such as 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD). In this work we studied TCDD and representative PCB congeners, alone and in mixture, for their effect on CYP1A gene transcription and protein levels in primary rat hepatocytes. Together with our previous work, our results suggest that formation of the Ah receptor-ligand-DRE (dioxin response element) complex is the principal point of divergence in the mechanism between an AhR agonist and an AhR antagonist. The coplanar PCBs 77 and 126 and the mono- ortho PCB 156 were full agonists toward CYP1A1 gene transcription and CYP1A protein levels, showing typical additive behavior with TCDD to the target molecule AhR. In contrast, the nonplanar PCB 153 antagonized the action of TCDD, even at concentrations that occupied a significant fraction of AhR molecules. Competitive inhibition explains the commonly reported decrease of ethoxyresorufin- O -deethylase (EROD) activity when PCBs are present in high concentrations and the antagonism of PCBs to the EROD activity of TCDD. The result is that Western blotting offers a much more reliable measure of CYP1A protein concentration than does the EROD assay, despite the greater convenience of the latter. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 480,489, 2004. [source]


    Impact of changes in analytical techniques for the measurement of polychlorinated biphenyls and organochlorine pesticides on temporal trends in herring gull eggs

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2010
    Shane R. de Solla
    Abstract Changes in analytical approaches during the tenure of monitoring programs for organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs) may affect estimates of temporal trends. We used an in-house reference material to create multiplication factors to adjust the estimates of OC pesticides and PCBs (Aroclor equivalents) in Great Lake herring gull eggs analyzed using electron capture detection (1987,1997) to be more equivalent to estimates using mass spectrometric detection (1998,2005) as well as accompanying differences in analytical procedures. We examined temporal trends in contaminant concentrations in herring gull eggs using change point regressions, to determine whether significant changes in long-term trends were associated with analytical methodology. The highest frequency of change point occurrences shifted from 1997 (when analytical methodology was altered) to 2003 after data adjustment. The explanatory power (r2) of the regressions was lower after adjustment, although only marginally so (mean r2 difference,=,0.04). The initial rates of decline before change points in contaminant concentrations were generally slower after the data adjustment, but after any change points the declines were not significantly different. The regression models did not change for 83.3% of the cases. The effects on the interpretation of long-term temporal trends in herring gull eggs, although not negligible, were minor relative to the magnitude of the temporal changes. Environ. Toxicol. Chem. 2010;29:1476,1483. © 2010 SETAC [source]


    Tissue-specific distribution and whole-body burden estimates of persistent organic pollutants in the bottlenose dolphin (Tursiops truncatus)

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2010
    Jennifer E. Yordy
    Abstract Most exposure assessments for free-ranging cetaceans focus on contaminant concentrations measured in blubber, and few data are available for other tissues or the factors governing contaminant distribution among tissues. The goal of this study was to provide a detailed description of the distribution of persistent organic pollutants (POPs) within the common bottlenose dolphin (Tursiops truncatus) body and assess the role of lipid dynamics in mediating contaminant distribution. Thirteen tissues (brain, blubber, heart, liver, lung, kidney, mammary gland, melon, skeletal muscle, spleen, thyroid, thymus, and testis/uterus) were sampled during necropsy from bottlenose dolphins (n,=,4) and analyzed for lipid and 85 POPs, including polychlorinated biphenyls, organochlorine pesticides, and polybrominated diphenyl ethers. Significant correlations between tissue POP concentrations and lipid suggest that distribution of POPs is generally related to tissue lipid content. However, blubber:tissue partition coefficients ranged widely from 0.753 to 6.25, suggesting that contaminant distribution is not entirely lipid-dependent. Tissue-specific and whole-body contaminant burdens confirmed that blubber, the primary site of metabolic lipid storage, is also the primary site for POP accumulation, contributing >90% to the whole-body burdens. Observations also suggest that as lipid mobilizes from blubber, contaminants may redistribute, leading to elevated tissue concentrations. These results suggest that individuals with reduced blubber lipid may be at increased risk for exposure-related health effects. However, this study also provides evidence that the melon, a metabolically inert lipid-rich structure, may serve as an alternate depot for POPs, thus preventing the bulk of blubber contaminants from being directly available to other tissues. This unique physiological adaptation should be taken into consideration when assessing contaminant-related health effects in wild cetacean populations. Environ. Toxicol. Chem. 2010;29:1263,1273. © 2010 SETAC [source]


    Polybrominated diphenyl ether flame retardants in Chesapeake Bay region, USA, peregrine falcon (Falco peregrinus) eggs: Urban/rural trends,,

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2009
    Katherine E. Potter
    Abstract A total of 23 peregrine falcon (Falco peregrinus) eggs were obtained between 1993 and 2002 from 13 nests, encompassing 11 locations in the Chesapeake Bay region, USA. When multiple eggs were available from the same clutch, average clutch contaminant concentrations were calculated. An overall median total polybrominated diphenyl ether (PBDE) level of 201 ng/g wet weight was determined for the eggs/clutches examined. The maximum in an individual egg, from an urban highway bridge site, was 354 ng/g. This egg also exhibited the highest BDE 209 burden (48.2 ng/g). Compared to distributions reported in fish and piscivorous birds, falcon eggs were enriched in the more brominated congeners. The BDE congeners 153, 99, and 100 constituted 26.0, 24.8, and 13.1%, respectively, of total PBDEs. In most aquatic species, BDE 47 is the most abundant congener reported; however, it constituted only 4.4% of total PBDEs in the eggs of the present study. The median BDE 209 concentration was 6.3 ng/g. The sum of the octa- to nonabrominated congeners (BDEs 196, 197, 206, 207, and 208) contributed, on average, 14.0% of total PBDEs, exceeding the contribution of BDE 209 (5.9%). Concentrations of polychlorinated biphenyls (PCBs) and 1,1-dichloro-2,2-bis(p -chlorophenyl)ethylene (4,4,-DDE) also were determined in a subset of 16 eggs (collected in 2001,2002 from six nests) and were an order of magnitude greater than the corresponding PBDEs. Median BDE 209 concentrations were significantly correlated (p < 0.01, Spearman R = 0.690) with the human population density of the area surrounding the nest. Total PBDEs, total PCBs, and 4,4,-DDE levels were not correlated to human population density. [source]


    Estrogenic effects of polychlorinated biphenyls and relation to cytochrome P4501A activity in the endangered goodeid fish Ameca splendens,

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2008
    Armando Vega-López
    Abstract The present study examines the relationships between cytochrome P4501A (CYP1A) activity and vitellogenin (VTG) induction in Ameca splendens elicited by a polychlorinated biphenyl (PCB) mixture. Ethoxyresorufin- O -deethylase (EROD) activity, mRNA levels of VTG, and VTG induction were evaluated in male and female fish exposed for 1, 2, 4, 8, and 16 d to a commercial PCB mixture. Polychlorinated biphenyls induced higher EROD in both sexes and this induction was higher in females than in males. Maximum EROD and VTG induction occurred on day 1 in females, while in males these maxima occurred on days 8 and 16. A correlation between EROD and VTG induction was found only in males (p < 0.001), and VTG induction was also higher in males than in females (p < 0.01). Exposure to PCBs elicited increases in VTG expression and induction over time in males, while in females these decreased at the end of the exposure period. Deficiencies in the feedback mechanisms of male A. splendens exposed in the wild to xenoestrogens such as PCBs have probably contributed to alter the sex ratio of wild populations of this species. [source]


    Predicting world health organization toxic equivalency factor dioxin and dioxin-like polychlorinated biphenyl levels in farmed atlantic salmon (Salmo salar) based on known levels in feed

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2007
    Marc H. G. Berntssen
    Abstract Assimilation and elimination rate constant of dietary polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DLPCBs) with a World Health Organization toxic equivalency factor (WHO-TEF) were estimated in market-size Atlantic salmon (Salmo salar) using fish that were previously fed vegetable oil,based (low in PCDD/Fs and DLPCBs) or fish oil,based (high in PCDD/Fs and PCBs) diets. At the start of the kinetic trial, half the fish that were fed fish oils were fed vegetable oil feeds and inverted (cross-over design) for five months. The assimilation efficiencies of the PCDD/F congeners were more variable (3,89%) and, generally, were lower than those of the DLPCBs (70,80%). Among the PCDD/F congeners, the assimilation efficiency of the most toxic tetra- and pentachlorinated PCDD/Fs was greater than that of higher-chlorinated PCDD/Fs. Elimination rates for DLPCBs were higher than those for PCDD/Fs. Lower-chlorinated PCDDs had a lower elimination rate than the higher-chlorinated PCDDs, but no differences were observed among PCDF congeners or DLPCB congeners. Kinetic parameters were used to predict the level of WHO-TEF dioxins and DLPCBs in Atlantic salmon reared in a large-scale facility under commercial conditions. Predictions were based on preanalyzed levels of these organochlorines in feeds with three different replacement levels (0, 30, and 60%) of vegetable oil. A simple one-compartmental, first-order kinetic model was used to predict the level of sum WHO toxic equivalents for PCDD/Fs and DL-PCBs. The predicted values varied by 0 to 11% from the measured values in the commercially reared salmon. [source]


    Applicability of spraints for monitoring organic contaminants in free-ranging otters (Lutra lutra)

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2006
    Nico W. van den Brink
    Abstract In the current study, the use of spraints for monitoring levels of polychlorinated biphenyls (PCBs) in individual otters was experimentally validated. On the basis of a detailed pattern analysis, it is concluded that in the current study, PCB concentrations in spraints that contain relatively high concentrations of nonmetabolizable PCB congeners (PCB 138 and 153>42.5% of total PCB concentrations) reflect the internal PCB concentrations of the otter that produced the spraint. In general, however, spraints should be selected that contain relative concentrations of PCB 138 and PCB 153>95th percentile of these congeners in samples from local food items of otters. On the basis of relationships between levels in spraints and internal levels and on earlier reported effect concentrations, a threshold level range of 1.0 to 2.3 ,g/g (lipid normalized) in such spraints is proposed. The validated methods to monitor PCBs in otters may be combined with genetic marker techniques that can assess the identity of the otter that produced the spraints. In such a design, it is feasible to monitor PCB levels in individual free-ranging otters in a truly animal friendly way. [source]


    Concentrations and partitioning of polychlorinated biphenyls in the surface waters of the southern Baltic Sea,seasonal effects

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2006
    Kilian E.C. Smith
    Abstract In the marine environment, the partitioning of hydrophobic organic contaminants, such as polychlorinated biphenyls (PCBs), between the dissolved and suspended matter phases in the water column plays a fundamental role in determining contaminant fate (e.g., air,water exchange or food-chain uptake). Despite the pronounced seasonality in physical, chemical, and biological conditions in temperate marine ecosystems, little is known about the seasonality in organic contaminant partitioning behavior. Surface water from the western Baltic Sea was sampled regularly during an 18-month period between February 2003 and July 2004. The concentrations of seven PCB congeners were determined in the dissolved and particulate organic carbon (POC) phases. An inverse relationship was found between KPOC (i.e., the ratio between the POC-normalized PCB concentration [pg/kg POC] and the dissolved concentration [pg/L]) and temperature. The decrease in the water temperature of 20°C between summer and winter resulted in an increase in KPOC by a factor of approximately five. The POC-normalized PCB concentrations were higher in winter than in summer by a factor of 9 to 20. This reflected the higher KPOC and somewhat greater PCB concentrations in the dissolved phase, and it could have consequences for bioaccumulation of these chemicals in aquatic food webs. The results demonstrate a clear seasonality in contaminant partitioning in the temperate marine environment that should be accounted for when interpreting field data or modeling contaminant fate. [source]


    Elevated organochlorines in the brain,hypothalamic,pituitary complex of intersexual shovelnose sturgeon

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2006
    Brian T. Koch
    Abstract Organochlorine compounds (OCs), including polychlorinated biphenyls and organochlorine pesticides, were used on lands adjacent to the Middle Mississippi River (MMR; USA) from 1930 through 1988, and they continue to occur in MMR fish. These compounds are estrogenic and/or antiandrogenic, and they alter hormone production and reception within the brain and gonads of male fish, resulting in intersexuality and/or suppressed gonadal development. To assess how OCs affect reproduction of MMR fish, we quantified OC accumulation, intersexuality, and gonadal development in male shovelnose sturgeon (Scaphirhynchus platorynchus) throughout the MMR during the spring of 2003. Gonads were observed for intersexual characteristics, weighed to calculate the gonadosomatic index (GSI), and examined histologically. Tissue accumulation of OCs was quantified in gonads, brain,hypothalamic,pituitary (BHP) complex, and fillets. Four of 48 mature males were identified macroscopically as intersexuals, and a fifth was found through histology (a 10.4% incidence). Intersexuals accumulated higher concentrations of OCs in the BHP complex compared with those of mature males. In addition, GSI and OC accumulation within the BHP complex, gonads, and fillets of mature males were negatively related. Exposure to OCs before or during sexual differentiation likely induces intersexuality in MMR shovelnose sturgeon, and exposure throughout gonadal maturation inhibits gonadal development. [source]


    Determination of polychlorinated biphenyl and polycyclic aromatic hydrocarbon elimination rates in adult green and leopard frogs

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2006
    Jocelyn L. Leney
    Abstract The purpose of the present study was to quantify elimination kinetics of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in adult green frogs (Rana clamitans) and leopard frogs (Rana pipiens). Three experiments were conducted: PCB elimination rate constants were determined for both frog species, and PAH elimination rate constants were determined for leopard frogs only. In green frogs, significant PCB elimination rate constants ranged from 0.013 to 0.04 d,1 (time for frogs to achieve 90% steady state with water [t90] = 57.8-178.2 d). In leopard frogs, significant PCB elimination rate constants ranged from 0.004 to 0.047 d,1 (t90 = 48.8-657.9 d). Polycyclic aromatic hydrocarbon elimination in leopard frogs was faster than PCB elimination in either frog species: Significant PAH rate constants ranged from 0.069 to 0.188 d,1 (t90 = 12.2-33.5 d). In both species, and for both PCBs and PAHs, a significant inverse relationship was found between the chemical elimination rate constant and Kow. These results show that adult anurans have relatively low elimination rates of PCBs but exhibit a small capacity for metabolic biotransformation of PAHs that is comparable to that of invertebrates but lower than that of fish. These findings suggest that adult amphibians have the potential to be used as biomonitors for persistent organic chemicals. [source]


    Bioaccumulation and trophic transfer of polychlorinated biphenyls by aquatic and terrestrial insects to tree swallows (Tachycineta bicolor)

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2006
    Jonathan D. Maul
    Abstract Insectivorous passerines often bioaccumulate polychlorinated biphenyls (PCBs) via trophic transfer processes. Tree swallows (Tachycineta bicolor) frequently are used for estimating PCB bioaccumulation, yet the focus on specific trophic links between contaminated sediment and bird has been limited. Bioaccumulation of PCBs from sediment to tree swallows was examined with focus on trophic pathways by simultaneously examining PCBs in emergent aquatic and terrestrial insects and gut contents of nestlings. Total PCB concentrations increased from sediment (123.65 ± 15.93 ,g/kg) to tree swallow nestlings (2,827.76 ± 505.67 ,g/kg), with emergent aquatic insects, terrestrial insects, and gut content samples having intermediate concentrations. Biota-sediment accumulation factors (BSAFs) varied among congeners for tree swallow nestlings and for male and female Chironomus spp. For nestlings, the highest BSAF was for the mono- ortho -substituted congener 118. Nestling biomagnification values were similar for gut contents and female Chironomus spp., suggesting this diet item may be the main contributor to the overall PCB transfer to nestlings. However, gut content samples were highly variable and, on a PCB congener pattern basis, may have been influenced by other taxa, such as terrestrial insects. Considering dietary plasticity of many insectivorous birds, the present study suggests that a variety of potential food items should be considered when examining PCB accumulation in insectivorous passerines. [source]


    Bioconcentration of persistent organic pollutants in four species of marine phytoplankton

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2005
    Antje Gerofke
    Abstract The uptake of polychlorinated biphenyls (PCBs) was studied in four species of marine algae. A novel experimental system to establish and maintain constant dissolved concentrations of PCBs was employed. Headspace sampling was used to verify that the freely dissolved concentrations remained constant with time. The headspace analysis also allowed sorption to dissolved organic carbon (DOC) to be quantified for all but the most lipophilic PCB congeners. Equilibration with the dissolved phase was rapid for three of the four algae species (<1 d for the majority of congeners). Organic carbon,normalized algae/water partition coefficients (KAlgW) were similar for three of the four species, but were lower by a factor of 10 to 20 for Phaeodactylum tricornutum. The KAlgW values of the first three species were similar to the octanol/water partition coefficient (KOW) for those PCB congeners for which DOC sorption could be quantified. These KAlgW values also agreed well with organic carbon,normalized bioconcentration factors for PCBs in suspended particulate matter (BCFSPM) sampled in Baltic Sea surface water during the summer. [source]


    Effects of maternally transferred organochlorine contaminants on early life survival in a freshwater fish

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2005
    Thomas A. Johnston
    Abstract Laboratory research has shown that female fish can pass toxic organochlorines (OCs) from their bodies to their eggs, killing their offspring if sufficient quantities are transferred. We conducted a controlled incubation study using gametes from a wild, OC-contaminated walleye (Sander vitreus) population (Bay of Quinte, Lake Ontario, Canada) in order to assess among-female variation in offspring early life survival in relation to ova concentrations of planar OCs (polychlorinated dibenzo- p -dioxins and furans and planar polychlorinated biphenyls) and a suite of other maternal and ova characteristics. Equal volumes of ova from each female were fertilized, pooled, and incubated together as an experimental cohort. Relative survival of each female's offspring was estimated as the proportion of surviving larvae (at ,5 d posthatch) that she contributed to the cohort as determined by microsatellite DNA parentage assignment. Total planar OC concentration (expressed as toxic equivalency of 2,3,7,8-tetrachloro-dibenzo- p -dioxin) of ova was positively related to maternal age and size and to ova lipid content. However, early life survival did not decline with increasing ova planar OC concentrations. Similarly, we observed no significant relationships between early life survival and ova thiamine content, ova fatty acid composition, or maternal age or size. Early life survival was more strongly correlated with date of spawn collection, thyroid hormone status of the ova, and ovum size. Maternally transferred planar OCs do not appear to negatively influence female reproductive success in this walleye population. [source]


    Effects of dose and particle size on activated carbon treatment to sequester polychlorinated biphenyls and polycyclic aromatic hydrocarbons in marine sediments

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2005
    John R. Zimmerman
    Abstract Recent laboratory studies show that mixing activated carbon with contaminated sediment reduces the chemical and biological availability of hydrophobic organic contaminants. In this study, we test the effects of varying the activated carbon dose and particle size in reducing the aqueous availability of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) and the uptake of PCBs by two benthic organisms. We mixed PCB- and PAH-contaminated sediment from Hunters Point Naval Shipyard, San Francisco Bay (CA, USA), for one month with activated carbon, at doses of 0.34, 1.7, and 3.4% dry mass basis. We found that increasing the carbon dose increased the effectiveness in reducing PCB bioaccumulation. In 56-d uptake tests with the benthic organisms Neanthes arenaceodentata and Leptocheirus plumulosus, PCB bioaccumulation was reduced by 93 and 90%, respectively, with 3.4% carbon. Increasing the dose also increased the effectiveness in reducing PCB and PAH aqueous concentrations and uptake by semipermeable membrane devices and quiescent flux of PCBs to overlying water. Decreasing activated carbon particle size increased treatment effectiveness in reducing PCB aqueous concentration, and larger-sized activated carbon (400,1,700 ,m) was ineffective with a contact period of one month. We invoke a numerical model based on intraparticle diffusion in sediment and activated carbon particles to help interpret our experimental results. This model was useful in explaining the trends for the effect of activated carbon dose and particle size on PCB aqueous concentrations in well-mixed systems. [source]


    Association between lymphocyte proliferation and polychlorinated biphenyls in free-ranging harbor seal (Phoca vitulina) pups from British Columbia, Canada

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2005
    Milton Levin
    Abstract Recent pinniped die-offs have led to the speculation that persistent organic pollutants (POPs) are immunomodulatory, making individuals more susceptible to viral infections. Eighteen healthy harbor seal (Phoca vitulina) pups (aged 3,4 weeks) were live-captured from southern British Columbia, Canada, and maintained temporarily in captivity for an immunotoxicological assessment. The relationships between mitogen-induced peripheral blood lymphocyte proliferation and blubber concentrations of three major immunotoxic POP classes (the polychlorinated biphenyls [PCBs], polychlorinated dibenzo- p -dioxins [PCDDs], and the polychlorinated dibenzofurans [PCDFs]) were evaluated. A significant body weight-independent positive correlation was observed between both T-cell mitogen (phytohemagglutinin [PHA])- and B-cell mitogen (lipopolysaccharide [LPS])-induced lymphocyte proliferation and the blubber concentrations of total PCB. Best subset regression analysis revealed that total PCBs, and not total PCDD or total PCDF, explained 24 and 29% of the changes in both T-cell mitogen-and B-cell mitogen-induced lymphocyte proliferation, respectively. Further regression analysis performed on the PCB classes measured in this study showed that di - ortho PCBs accounted for 25 and 30% of the changes in both T-cell and B-cell lymphocyte proliferation, respectively. Results suggest that POPs, and PCBs in particular, are associated with changes in lymphocyte proliferation, something that could result in increased susceptibility to infections in harbor seal pups. Further research is needed to evaluate the relative roles of natural and contaminant-related influences on the immune system of marine mammals. [source]


    Exposure and effects of 2,3,7,8-tetrachlorodibenzo- p -dioxin in tree swallows (Tachycineta bicolor) nesting along the Woonasquatucket River, Rhode Island, USA,

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2005
    Christine M. Custer
    Abstract Concentrations of 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) in tree swallows (Tachycineta bicolor) nesting along the Woonasquatucket River northwest of Providence (RI, USA) in 2000 and 2001 were some of the highest ever reported in avian tissues. Mean concentrations in eggs ranged from 300 to > 1,000 pg/g wet weight at the two most contaminated ponds, Allendale and Lyman. Mean egg concentrations at Greystone, the upstream reference pond, were 12 and 29 pg/g. Positive accumulation rates and concentrations in diet samples from 12-day-old nestlings indicated that the contamination was accumulated locally. Concentrations in diet of between 71 and 219 pg/g wet weight were more than 6 and 18 times higher than concentrations considered safe for birds (10,12 pg/g). Hatching success was negatively associated with concentration of TCDD in eggs. Only about half the eggs hatched at Allendale compared with >77% at Greystone. The national average for hatching success in successful nests is 85%. No other contaminants, such as polychlorinated biphenyls and mercury, were present in any sample at concentrations known to affect avian reproduction. Three bioindicators, half-peak coefficient of geometric variation, ethoxyresorufin- O -dealkylase activity, and brain asymmetry were assessed relative to TCDD contamination. [source]


    Evaluation of the role of black carbon in attenuating bioaccumulation of polycyclic aromatic hydrocarbons from field-contaminated sediments,

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2004
    Brita Sundelin
    Abstract The significance of black carbon (BC) for the bioavailability of polycyclic aromatic hydrocarbons (PAHs) was examined by using historically contaminated intact sediment cores in laboratory exposure experiments with the deposit-feeding amphipod Monoporeia affinis. Log values of amphipod biota,sediment accumulation factors (BSAFs) were significantly related to log BC, whereas log BSAFs were related to log octanol,water partition coefficients only in background sediments containing less BC. In the background sediments, the BSAF for polycyclic aromatic hydrocarbons (PAHs) was 1 to 2 for phenanthrene, with lower values for more hydrophobic PAHs, indicating an increase in nonequilibrium conditions with increasing PAH molecular size. For the near-equilibrated phenanthrene and fluoranthene, higher BSAFs were measured during exposure to background sediments, with BSAF decreasing to <0.1 in contaminated sediments in the Stockholm waterways. In situ caged mussels (Dreissena polymorpha) exhibited field BSAF values (relative to sediment-trap,collected suspended matter) for polychlorinated biphenyls (PCBs) of 0.1 to 0.4, but for PAHs of similar hydrophobicity and molecular size, the field BSAFs were much lower and in the range 0.002 to 0.05. This PAH,PCB dichotomy is consistent with recently reported much stronger binding to diesel soot (a form of BC) for PAHs than for PCBs of equal hydrophobicities. Lower BSAFs for the near-equilibrated PAHs (phenanthrene and fluoranthene) in the urban sediments relative to the background sediments were consistent with the larger presence of BC in the urban sediments. This study provides the first linked BSAF,BC field data that supports a causal relationship between strong soot sorption and reduced bioavailability for PAHs. [source]