First assessment of persistent organic pollutants and halogenated natural compounds in an omnivorous resident coral-reef fish species, black triggerfish, Melichthys niger, from an Atlantic oceanic island, Brazil.

Studies on the occurrence of POPs and other persistent compounds in pristine areas are extremely valuable, as they offer insights on the long-range transportation of POPs and the occurrence of natural compound producers' areas. In this regard, this study aimed to report data of both anthropogenic (polychlorinated biphenyls, PCBs, and polybrominated diphenyl ethers, PBDEs) and natural (methoxylated PBDEs, MeO-BDEs) compounds in tissues of the black triggerfish, Melichthys niger (Tetraodontiformes, Balistidae), specimens (n = 30) sampled in 2018 during a scientific expedition conducted at Trindade Island. Concentrations of ∑28PCBs ranged from 73 to 1052 ng g-1 lw in liver, 334 to 1981 ng g-1 lw in gonads, and 20 to 257 ng g-1 lw in muscle, with the predominance of PCB-180 in liver and PCB-52 in gonad and muscle. Concentrations of ∑7PBDEs ranged from

Comparative effects of oral exposure to 2, 4, 6-tribromophenol and decabromodiphenyl ether in Nile tilapia.

Flame retardants are compounds added to a high diversity of polymers used in electronics and furniture to decrease the risk of combustion. Decabromodiphenyl ether (BDE-209) is a polybrominated diphenyl ether (PBDE) congener still used worldwide, while 2, 4, 6-tribromophenol(TBP) is a PBDE metabolite used as a pesticide and flame retardant for wood conservation. These compounds have lipophilic properties and are easily bioaccumulated in the food chain. In the current study, the acute and chronic toxicity of BDE-209 and TBP was evaluated in Oreochromis niloticus through analyses of redox imbalance, neurotoxicity, and histopathological biomarkers after acute (24, 48, 72, and 96 h) and chronic (90 days) exposure to 0.5, 5, and 50 ng/g of the polybrominated compounds. The results showed effects on glutathione S-transferase(GST) activity and damage to biomolecules in both acute and chronic exposures. Liver histopathology and the ultrastructure of hepatocytes revealed alterations and damage in individuals from both experiments, but only BDE-209 led to neurotoxic effects. The current study revealed new endpoints related to polybrominated compounds in fish, highlighting the need to review the risk of exposure to biota.

Adipogenesis Regulation and Endocrine Disruptors: Emerging Insights in Obesity.

Endocrine disruptors (EDs) are defined as environmental pollutants capable of interfering with the functioning of the hormonal system. They are environmentally distributed as synthetic fertilizers, electronic waste, and several food additives that are part of the food chain. They can be considered as obesogenic compounds since they have the capacity to influence cellular events related to adipose tissue, altering lipid metabolism and adipogenesis processes. This review will present the latest scientific evidence of different EDs such as persistent organic pollutants (POPs), heavy metals, "nonpersistent" phenolic compounds, triclosan, polybrominated diphenyl ethers (PBDEs), and smoke-derived compounds (benzo -alpha-pyrene) and their influence on the differentiation processes towards adipocytes in both in vitro and in vivo models.

First assessment of persistent organic pollutant contamination in blubber of Chilean blue whales from Isla de Chiloé, southern Chile.

Persistent organic pollutants (POPs) were assessed for the first time in blue whales from the South Pacific Ocean. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethane and its main metabolites (DDTs), were determined in 40 blubber samples from 36 free-ranging individuals and one stranded, dead animal along the coast of southern Chile between 2011 and 2013. PCBs were the most abundant pollutants (2.97-975 ng/g l.w.), followed by DDTs (3.50-537 ng/g l.w.), HCB (nd-77.5 ng/g l.w.) and PBDEs (nd-33.4 ng/g l.w). There was evidence of differences between sexes, with lower loads in females potentially due to pollutants passing to calves. POP concentrations were higher in specimens sampled in 2013; yet, between-year differences were only statistically significant for HCB and PBDEs. Lower chlorinated (penta > tetra > tri) and brominated (tetra > tri) congeners were the most prevalent among PCBs and PBDEs, respectively, mostly in agreement with findings previously reported in blue and other baleen whales. The present study provides evidence of lower levels of contamination by POPs in eastern South Pacific blue whales in comparison to those reported for the Northern Hemisphere.

Transplacental transfer of persistent organic pollutants in La Plata dolphins (Pontoporia blainvillei; Cetartiodactyla, Pontoporiidae).

Persistent organic pollutants (POPs) accumulate in the fat tissue of living organisms and are found in relatively high concentrations in animals at the top of the food chain, such as dolphins. The ability of these compounds to interact with the endocrine system of marine mammals constitutes a risk for the reproduction and conservation of species. The La Plata dolphin, Pontoporia blainvillei, is exclusive to the southwestern Atlantic Ocean and is classified on the IUCN red list as a vulnerable species. Blubber, liver, kidney and muscle samples from four P. blainvillei mother-fetus pairs were analyzed to evaluate the transfer of POPs to fetal tissues through the placenta. The presence of POPs in fetal tissues indicates the maternal transfer of compounds. In the pregnant females, blubber was the tissue with POP highest concentration, followed by the liver, kidneys and muscles. In the fetuses, POP accumulation mainly occurred in the blubber followed by the muscles, liver and kidneys. Polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDTs) were found in all tissues analyzed and had the highest concentrations among all compounds. The main PCB congeners in the fetal samples had five to seven chlorine atoms. The only polybrominated diphenyl ether (PBDE) in the fetal samples was 47 and was found only in blubber. The main DDT metabolite in the fetuses was p,p'-DDE. POP transfer via the placenta occurs in the first months of gestation and increases with fetal development, according to fetus/mother (F/M) ratio: HCB>DDT>PCB>PBDE>Mirex, which may follow the order of the octanol/water partition coefficient (Kow) values.

Contamination status by persistent organic pollutants of the Atlantic spotted dolphin (Stenella frontalis) at the metapopulation level.

The Atlantic spotted dolphin (Stenella frontalis) is an endemic species of the tropical-temperate Atlantic Ocean with widespread distribution. Although this species has been the subject of a large number of studies throughout its range, it remains in the "data deficient" category of the International Union for Conservation of Nature (IUCN). Chemical pollution by persistent organic pollutants (POPs) has been listed as one of the major threats to this species, however, there is no information on a wide scale. Thus, the aim of the present study was to investigate the contamination status of spotted dolphins on the metapopulation level as well as determine spatial and temporal variations in POP concentrations and bio-accumulation. A total of 115 blubber samples collected from a large part of the Atlantic basin were analysed for PCBs, DDTs, PBDEs, chlordanes, HCB and mirex. Although PCBs and DDTs were the predominant compounds in all areas, inter-location differences in POP concentrations were observed. Dolphins found at São Paulo, southeastern coast of Brazil, had the highest PCB concentrations (median: 10.5 µg/g lw) and Canary Islands dolphins had the highest DDT concentrations (median: 5.13 µg/g lw). Differences in PCB patterns among locations were also observed. Dolphins from the Azores and São Paulo demonstrated a similar pattern, with relatively highly contributions of tetra- (6.8 and 5.2%, respectively) and penta-CBs (25.6 and 23.8%, respectively) and lower contributions of hepta-CBs (20.8 and 23.5%, respectively) in comparison to other areas. Moreover, the sex of the animals and the year in which sampling or capture occurred exerted an important influence on the majority of the POPs analysed. Comparisons with toxicity thresholds available in the literature reveal that the São Paulo and Canary Island dolphins are the most vulnerable populations and should be considered in future conservation and management programs for the Atlantic spotted dolphin.

Seasonal Differences in Contaminant Accumulation in Neotropical Migrant and Resident Songbirds.

For many years, it has been hypothesized that Neotropical migrants breeding in the United States and Canada accumulate organochlorine pesticides (OCPs) while on their wintering grounds in Latin America. We investigated the seasonal accumulation of persistent organic pollutant (POPs) in migrant and resident passerines in Texas, Yucatán, and Costa Rica collected during the fall, winter, and spring from 2011 to 2013. A total of 153 birds were collected, and all contained detectable levels of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and OCPs with dichlorodiphenyldichloroethylene (DDE) being the most predominant pesticide. OCPs and PCBs were the predominant contaminants, accounting for ≥80 % of the total POPs burden, whereas PBDEs accounted for ≤16 %. Only spring migrants from Texas had significantly greater DDE concentrations (64.6 ng/g dry weight [dw]) than migrants collected in Costa Rica (23.2 ng/g dw). Resident birds in Texas had significantly greater levels of DDE (121 ng/g dw) and ΣPBDEs (34.8 ng/g dw) compared with residents in Yucatán and Costa Rica. For ΣPCBs, resident birds from Costa Rica had significantly lower concentrations (9.60 ng/g dw) compared with their migrant counterparts (43.7 ng/g dw) and residents from Texas (48.3 ng/g dw) and the Yucatán (32.1 ng/g dw). Migrant and resident passerines had similar congener profiles for PCBs and PBDEs suggesting similar exposure and retention of these contaminants. No significant accumulation of DDE was observed in migrants while on their wintering grounds. Relatively high concentrations of PBDEs in resident birds from Costa Rica warrant future studies of PBDE contamination in Latin America.

Mechanisms of interaction between persistent organic pollutants (POPs) and CYP2B6: An in silico approach.

Human Cytochrome P450s (CYP450) are a group of heme-containing metalloenzymes responsible for recognition and metabolism of numerous xenobiotics, including drugs and environmental contaminants. CYP2B6, a member of CYP450, is well known for being a highly inducible and polymorphic enzyme and for its important role in the oxidative metabolism of environmental pollutants, such as the Polybrominated Diphenyl Ethers (PBDEs) and Polychlorinated Biphenyls (PCBs). However the mechanisms of interaction of PBDEs and PCBs with CYP2B6 is not entirely known. In this work, a computational approach was carried out to study the interactions of 41 POPs (17 PBDEs, 17 PCBs, and 7 Dioxins) with four CYP2B6 protein structures downloaded from PDB data base (PDB: 3UA5, 3QOA, 3QU8 and 4I91) using molecular docking protocols with AutoDock Vina. The best binding affinity values (kcal/mol) were obtained for PBDE-99 (-8.5), PCB-187 (-9.6), and octachloro-dibenzo-dioxin (-9.8) that can be attributed to the hydrophobic interactions with important residues, such as Phe-363, in the catalytic site of CYP2B6. Molecular docking validation revealed the best values for PDB: 3UA5 (R = 0.622, p = 0.001) demonstrating the reliability of molecular docking predictions. The information obtained in this work can be useful in evaluating the modes of interaction of xenobiotic compounds with the catalytic site of CYP2B6 and provide insights on the important role of these enzymes in the metabolism of potentially toxic compounds in humans.

Uptake, metabolism and sub-lethal effects of BDE-47 in two estuarine invertebrates with different trophic positions.

Two microcosm types -sediment-biota and biota-biota- were constructed to simulate different pathways of BDE-47 uptake, metabolism and oxidative stress effects in two key estuarine invertebrates (polychaete Laeonereis acuta and crab Cyrtograpsus angulatus). In the sediment-biota experiment, both species were exposed to spiked sediments; an environmentally reported and a high concentration of BDE-47 for 2 weeks. In the biota-biota experiment, crabs were fed with polychaetes pre-exposed to BDE-47 in the sediment-biota experiment. The sediment-biota experiment first revealed that polychaetes significantly accumulated BDE-47 (biota-sediment accumulation factor >2; p < 0.05) to a much greater extent than the crab organs (muscle, hepatopancreas, gills) at both sediment concentrations. For oxidative stress responses, polychaete and crab tissues exposed to spiked sediment showed a significant increase (p < 0.05) of only glutathione S-transferase (GST) activity with respect to controls in both BDE-47 concentrations. No lipid peroxidation (TBARS) or total antioxidant capacity (ACAP) changes were evident in the species or organs exposed to either BDE-47 sediment concentration. The biota-biota experiment showed that feeding crabs with pre-exposed polychaetes caused BDE-47 accumulation in organs as well as significant amounts of BDE-47 eliminated through feces (p < 0.05). Unlike the sediment-biota exposure, crabs fed with pre-exposed BDE-47 polychaetes showed the most conspicuous oxidative stress responses. Significant changes in GST and ACAP in both hepatopancreas and gills, in addition to enhanced TBARS levels in the hepatopancreas with respect to controls (p < 0.05), revealed that BDE-47 assimilated by invertebrates represents a potential source of toxicity to their predators. No methoxylated metabolites (MeO-PBDEs) were detected during BDE-47 metabolism in the invertebrates in either of the two different exposure types. In contrast, hydroxylated metabolites (OH-PBDEs) were detected in polychaetes and crab organs/feces in both experiments. Our results demonstrate that PBDE hydroxylation is one of the main biotransformation routes of BDE-47 in estuarine animals, which could be associated with the oxidative stress responses found.

Persistent organic pollutants (POPs) in fish with different feeding habits inhabiting a shallow lake ecosystem.

The occurrence of persistent organic pollutants (POPs) in the environment can affect organisms inhabiting aquatic systems, in particular shallow lakes that are vulnerable to environmental stressors. This study aimed to assess POPs accumulation and changes at histological and physiological levels in tissues of three fish species with different trophic habits. Gills, brain, muscle, liver and gonads of Odontesthes bonariensis, Oligosarcus jenynsii and Cyphocharax voga were collected from the shallow lake La Peregrina, located in an agricultural area from Argentina. In addition, contaminant levels in surface water (SW), suspended particulate matter (SPM) and bottom sediments (BS) were assessed. Histological lesions were evaluated in fish tissues and levels of vitellogenin (VTG) were assessed in plasma of male fish in order to correlate these alterations with the presence of POPs in the environment. Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined by GC-ECD. Biotic and abiotic samples showed the same POPs distribution pattern: OCPs>PCBs>PBDEs. Although tissue distribution of OCPs was species-specific, muscle showed the lowest levels in all species. The most abundant contaminants were endosulfans, suggesting their widespread use in the area. O. bonariensis showed the highest endosulfans levels in liver (184.2-219ngg(-1)wet w), which was associated with the high SPM levels considering this species is a filter feeder. The occurrence of PCBs and PBDEs shows the ubiquity of these pollutants in the area. Histological lesions in gills and liver of O. bonariensis and O. jenynsii, might be related with the high levels of endosulfans in these organs. The detection of VTG in males warns about a possible exposure to estrogenic compounds in the environment. In conclusion, the simultaneous exposure of fish to multiple environmental pollutants leads to different alterations, so measures should be taken in order to prevent their occurrence and toxic effects.

Persistent organic pollutants in juvenile Magellanic Penguins (Spheniscus magellanicus) in South America.

Magellanic penguins, Spheniscus magellanicus, are the most abundant penguins living in temperate regions of South America and are good indicators of environmental pollution in the region. Persistent organic pollutants (POPs) were detected in the liver of Magellanic penguins found debilitated or dead on the beaches of Brazil (states of Rio de Janeiro, Sao Paulo, Santa Catarina and Rio Grande do Sul) between 2008 and 2012 as well as in Uruguay and Chile in 2011. Polychlorinated biphenyls (PCBs) were more prevalent than organochlorine pesticides (DDTs ∼ HCB ∼ Drins) and polybrominated diphenyl ethers (PBDEs). Among PCBs, penta-, hexa- and hepta-chlorinated congeners were predominant. Concentrations of POPs were similar between the Pacific and Atlantic penguin populations, except for PCBs, which were relatively higher in the Pacific population. During the study years (2008-2012), large variations were found in organochlorine pesticides and PCBs tended to decline. Overall, the southern portion of South America has low concentrations of POPs, with either a constant trend or evidence of decline.

State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review.

Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed.

An assessment of PCB and PBDE contamination in two tropical dolphin species from the Southeastern Brazilian coast.

PCBs and PBDEs were determined in two dolphin species, Sotalia guianensis and Steno bredanensis, from an upwelling system off the Central-northern coast of Rio de Janeiro, Brazil. PCB levels varied from 0.040 to 0.75 µg g(-1) lw in muscles and from 0.022 to 1.32 µg g(-1)lw in liver samples from S. guianensis. In S. bredanensis, values varied from 0.085 to 11.3 µg g(-1) lw in muscles and from 0.024 to 18.6 µg g(-1) lw in livers. PCB-138, -153 and -180 were the major PCB congeners detected in both species, while BDE-47 was the predominant PBDE congener found in both species. Higher concentrations in S. bredanensis were possibly related to the different feeding habits for both delphinid species. These results contribute to extend the database on organic contamination in cetaceans from the southern hemisphere, understanding their distribution and environmental fate in Southeastern Brazil.

Ile-1781-Leu and Asp-2078-Gly Mutations in ACCase Gene, Endow Cross-resistance to APP, CHD, and PPZ in Phalaris minor from Mexico.

Herbicides that inhibit acetyl coenzyme A carboxylase (ACCase) are commonly used in Mexico to control weedy grasses such as little seed canarygrass (Phalaris minor). These herbicides are classified into three major families (ariloxyphenoxypropionates (APP), cyclohexanodiones (CHD), and, recently, phenylpyrazolines (PPZ)). In this work, the resistance to ACCase (APP, CHD, and PPZ) inhibiting herbicides was studied in a biotype of Phalaris minor (P. minor) from Mexico, by carrying out bioassays at the whole-plant level and investigating the mechanism behind this resistance. Dose-response and ACCase in vitro activity assays showed cross-resistance to all ACCase herbicides used. There was no difference in the absorption, translocation, and metabolism of the (14)C-diclofop-methyl between the R and S biotypes. The PCR generated CT domain fragments of ACCase from the R biotype and an S reference were sequenced and compared. The Ile-1781-Leu and Asp-2078-Gly point mutations were identified. These mutations could explain the loss of affinity for ACCase by the ACCase-inhibing herbicides. This is the first report showing that this substitution confers resistance to APP, CHD, and PPZ herbicides in P. minor from Mexico. The mutations have been described previously only in a few cases; however, this is the first study reporting on a pattern of cross-resistance with these mutations in P. minor. The findings could be useful for better management of resistant biotypes carrying similar mutations.

Bioaccumulation of dioxin-like PCBs and PBDEs by detritus-feeding fish in the Rio de la Plata estuary, Argentina.

A comparative analysis of bioaccumulation behavior of dioxin-like polychlorinated biphenyls (dlPCBs) and polybrominated biphenyl ethers (PBDEs) was conducted involving simultaneous measurements in settling particles and a detritivorous fish (Sabalo, Prochilodus linneatus) collected in the sewage impacted Buenos Aires coastal area. Focalization of dlPCBs and PBDEs along the detritus food chain is reflected by a 30-40-fold increase of dry weight PBDE and dlPCB concentrations from settling particles to fish (1.8 ± 1.0 to 58 ± 31 and 6.8 ± 3.9 to 281 ± 155 ng g(-1) dry weight (dw), respectively). In this transference, dlPCB congeners presented more conservative patterns than those of PBDEs, basically due to debromination of BDE 99 and 153 to BDE 47 in fish. Lipid/organic carbon-based biota-sediment accumulation factors (BSAFs) ranged between 5 and 20 (7.3 ± 3.0 and 16 ± 8.0 for PBDEs and dlPCBs). Congener-specific BSAF of dlPCBs suggested a lower bioavailability of more planar non-ortho-PCB versus mono-ortho-PCB suggesting higher affinity to organic matter. BSAFs of PBDEs differed markedly among bromine homolog groups, supporting the biotransformation-formation from higher brominated to lighter congeners. The log BSAFs-log K OW relationship of dlPCBs and PBDEs presented a parabolic pattern maximizing at log K OW 6-7, but PBDE curve differs reflecting biotransformation processes.

Fingerprint of persistent organic pollutants in tissues of Antarctic notothenioid fish.

In the present work, persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and metabolites, polybrominated diphenyl ethers (PBDEs), and hexachlorocyclohexane (HCH) were analyzed in three Antarctic notothenioids fish species: Trematomus newnesi (TRN), Notothenia coriiceps (NOC) and Notothenia rossii (NOR). The contribution of each POP-family to the total load was as follows: ΣPCB (40%)>ΣDDT (27%)>ΣPBDEs (23%)>ΣHCH (10%). Among the 23 PCB congeners analyzed, penta-CBs homologues were the prevalent group, followed by hexa-CBs and hepta-CBs. DDT and its metabolites presented the following trend: p,p'-DDT>p,p'-DDE~p,p'-DDD. PBDE profile was dominated by BDE-47 and BDE-99 congeners, followed by BDE-100>BDE-28>BDE-154, BDE-153. Among HCHs, the γ-HCH isomer was detected in all samples, constituting 69% total HCH load, while α-HCH and ß-HCH contributions were 15% and 16%, respectively. The levels of POPs reported here suggest that NOR and NOC are more susceptible to accumulate the analyzed contaminants than TRN, a species not previously analyzed for POPs. Distribution of POPs among different tissues of the three species (muscle, liver, gonads, and gills) was also investigated. Considering lipid weight, the general pattern of POPs distribution in tissues indicated that while gonads showed higher levels of PCBs, DDTs and HCH, the most significant PBDE concentrations were recorded in gills. Also, a comparative analysis of POPs concentration in fish samples from Antarctic area was included.

PBDE levels in franciscana dolphin (Pontoporia blainvillei): temporal trend and geographical comparison.

Total PBDE concentrations determined in archived blubber samples from franciscana dolphins (Pontoporia blainvillei) unintentionally captured in the Brazilian coastal region off Rio Grande do Sul State (FMA III) between 1994 and 2004 (n = 73) ranged from 7.9 to 65 ng g(-1) lipid weight in mature males, with an increase over the ten-year period. Total PBDE concentrations in blubber samples collected from the FAM II (n = 41) between 2002 and 2005 were higher (67.8 to 763.7 ng g(-1)lw) than those from FMA III. This is possibly due to the proximity to important industrial development sites in the state of São Paulo. Despite the differences in total concentrations, PBDE profiles were comparable and the PBDE concentrations decreased in the following order BDE 47>BDE99>BDE 100 for both FMA and for males and females as well as adults, juveniles and pups.

Could feeding habit and migratory behaviour be the causes of different toxicological hazard to cetaceans of Gulf of California (Mexico)?

In this work, a suite of diagnostic biomarkers was applied to seven cetacean species to evaluate the role of the feeding habits and migratory behavior in the toxicological status of these species from the Gulf of California, Mexico. We investigate the interspecific differences in cytochrome P450 1A1 and 2B (CYP1A1 and CYP2B, respectively), aryl hydrocarbon receptor and E2F transcription factor 1 and the contaminants levels [organochlorine compounds, polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs)] in four odontocete species (common bottlenose dolphin, long-beaked common dolphin, sperm whale and killer whale) and three mysticete species (blue whale, fin whale, and Bryde's whale) using skin biopsy. Differences in contaminant levels and molecular biomarker responses between the odontocete and mysticete species have been pointed out. The canonical discriminant analysis on principal component analysis factors, performed to reveal clustering variables, shows that odontocete are characterised by the highest levels of lipophilic contaminants compared to the mysticete, with the highest levels of polychlorinated biphenyls, dichlorodiphenyltrichloroethanes and PBDEs detected in killer whale and the lowest levels in Bryde's whale. The biomarker data show interspecific differences amongst the seven species, revealing highest CYP1A and CYP2B protein levels in the mysticete fish-eating species (Bryde's whale). In conclusion, three main factors seem to regulate the biomarker responses in these species: (a) the inductive ability of persistent organic pollutants and PAHs; (b) the different evolutionary process of the two CYPs related to the different feeding habits of the species; (c) the migratory/resident behaviour of the mysticete species in this area.

PBDEs, PCBs and organochlorine pesticides distribution in edible fish from Negro River basin, Argentinean Patagonia.

DDTs, endosulfans, HCHs, chlordanes, PCBs and PBDEs levels were determined in different tissues of patagonian silverside (Odontesthes hatcheri) from the Upper (UV), Middle (MV) and Lower (LV) valleys of the Negro River, Argentina. Results showed a direct relation between pollutant levels in fish and land uses along the basin. All tissues showed decreasing levels from headwaters (UV) to downstream (LV). A significant predominance of organochlorine pesticides (306-3,449 ng g(-1) lipid) followed by ΣPCBs (65-3,102 ng g(-1) lipid) and ΣPBDEs (22-870 ng g(-1) lipid) was observed in all tissues and valleys, suggesting agriculture as the main source of pollutants in this basin. Pesticides were dominated by DDTs (90% pp'-DDE) followed by endosulfan (α->ß->sulfate), γ-HCH and γ-chlordane showing the prevalence of legacy compounds. Endosulfan levels point out the current use of technical endosulfan in the surrounding areas. The highest PCBs and PBDEs concentrations observed in fish from UV were associated to hydroelectric power plants and industries established upstream. PCB fingerprint presented a prevailing contribution of hexa-CBs (66 ± 7%) and penta-CBs (27 ± 9%), with a similar composition to Aroclor 1254-1260. The predominance of BDE-47 (69 ± 17%) among PBDEs, followed by BDE-100 and BDE-99, suggests possible debromination processes. These results were similar to worldwide trends found in fishes and environmental compartments. PCBs levels in silverside muscles along the Negro River exceeded the maximum limits for safe consumption, suggesting a possible human health risk related to silverside ingest. Therefore, a continued long-term monitoring of organic contaminants in fishes is needed in order to assess the potential risk for human health.

Polybrominated diphenyl ethers in fat samples from White-chinned Petrels (Procellaria aequinoctialis) and Spectacled Petrels (P. conspicillata) off southern Brazil.

Polybrominated diphenyl ethers (PBDEs) have been gaining much visibility in environmental chemical studies due to their similarity to PCBs and growing reports of harmful effects. The fact that these contaminants have not yet undergone bans or restrictions on the global level underscores the need for data on their occurrence. In the present study, fat samples from 26 White-chinned Petrels (Procellaria aequinoctialis) and 3 Spectacled Petrels (P. conspicillata) collected dead ashore or as bycatch of longline fisheries in southern Brazil were analyzed to determine concentrations of seven congeners (IUPAC #28, 47, 99, 100, 153, 154 and 183). Concentrations of ΣPBDEs ranged from not detectable to 72.70 ng g(-1) (wet weight), comparatively lower than concentrations reported for seabird samples in northern hemisphere. The most detected congeners were 153, 154 and 183. This pattern is close to that previously reported for birds of the same group, but not those from the same region.