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1.
Ecotoxicol Environ Saf ; 192: 110317, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32061977

RESUMO

Laboratory studies of pollutant uptake kinetics commonly start shortly after experimental soil contamination when it is not clear if the processes between soil and chemicals are equilibrated and stabilized. For instance, when the concentration in soil quickly decreases due to initial biodegradation, bioaccumulation may show a peak-shape accumulation curve instead of conventional first order kinetics with a plateau at the end. The results of such experiments with soil freshly contaminated in the laboratory are then hardly comparable to bioaccumulation observed in soils from historically contaminated sites. Therefore, our study focused on the uptake kinetics of four hydrophobic organic compounds (pyrene, lindane, p,p'-DDT and PCB 153) in two laboratory-contaminated natural soils with different soil properties (e.g. total organic carbon content of 1.6 and 9.3%) aged for 203 days to mimic long-term contamination. For pyrene, the results surprisingly showed peak-shape accumulation curves despite long aging. It seems compound biodegradation might be significant in aged soils when the conditions change (e.g. by distribution to the experimental vessels) and this should be also considered when testing historically contaminated soils. For lindane, longer aging seems to guarantee stability of the soil-compound-earthworm system and the steady state was reached after 5 days of exposure. Furthermore, although concentrations of p,p'-DDT and PCB 153 in earthworms after 11-15-day exposure did not statistically differ, which is a commonly-used indicator that a steady state was reached, they continuously increased until the end of the exposure. Therefore, despite the aging, longer exposure was probably needed to reach the true equilibrium between concentrations in earthworms and soil. In summary, aging does not warranty the conventional first order kinetic curve with the equilibrium at the end of the exposure but may have diverse effects for compounds with different environmental properties and should be taken into account in the bioaccumulation factor calculation and the risk assessment.


Assuntos
Oligoquetos/metabolismo , Poluentes do Solo/farmacocinética , Animais , DDT/farmacocinética , Hexaclorocicloexano/farmacocinética , Interações Hidrofóbicas e Hidrofílicas , Cinética , Bifenilos Policlorados/farmacocinética , Pirenos/farmacocinética , Poluentes do Solo/química
2.
Arch Environ Contam Toxicol ; 78(2): 294-302, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31641780

RESUMO

Polychlorinated biphenyls (PCBs), which cause environmental pollution, are found in animal-based fatty foods. Due to their long half-life and lipophilic properties, they can accumulate in the fat tissues of cattle. The study was conducted to compare the PCB levels (PCB28, 52, 101, 118, 138, 153, and 180) in the different fat tissues (muscle, liver, kidney, spinal cord, lung, back fat, perihepatic fat, and perirenal fat) of cattle by age and gender. This information is also useful to evaluate the exposure risks for different bovine edible tissues. Therefore, 15 female and 15 male cattle under 24 months of age and 15 female and 15 male cattle over 24 months of age were used, and 480 samples were analyzed for target PCBs using gas chromatography-mass spectrometry. Of all the samples, two (50.2 µg/kg in perihepatic fat and 51.1 µg/kg in kidney) were found above the maximum residue limit; these samples were taken from the animals in the elderly female group (over 24 months). There were more PCBs in cattle older than 2 years. Muscle, kidney, and perihepatic fat presented higher PCB concentrations than other tissues, and perirenal fat presented lower PCB concentrations than other tissues. PCB101, PCB153, and PCB138 were found to have the highest contribution to the PCB concentration. Thus, it is concluded that perihepatic fat, muscle, or kidney should be sampled, particularly in routine residue monitoring, and specifically analyzed for PCB101, PCB153, and PCB138.


Assuntos
Tecido Adiposo/química , Bifenilos Policlorados/análise , Fatores Etários , Animais , Bovinos , Poluentes Ambientais/análise , Poluentes Ambientais/farmacocinética , Feminino , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas , Rim/química , Fígado/química , Masculino , Músculos/química , Bifenilos Policlorados/farmacocinética , Distribuição Tecidual , Turquia
3.
Obesity (Silver Spring) ; 27(11): 1865-1873, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31689012

RESUMO

OBJECTIVE: Persistent organic pollutants (POPs) are lipophilic environmental toxicants that accumulate in adipose tissue. Weight loss leads to mobilization and increased redistribution of these toxicants. Many are obesogens and endocrine disruptors. Increased exposure could pose long-term health risks. The study objective was to measure the changes in serum concentrations of lipophilic POPs during significant weight loss. METHODS: This study enrolled 27 patients at a university hospital in a longitudinal, 6-month, observational study examining changes in POP blood levels after bariatric surgery. The primary outcome was the changes in the concentrations of 24 polychlorinated biphenyls (PCBs), 9 organochlorine pesticides (OCPs), 11 polybrominated diphenyl ethers, 2,2',4,4',5,5'-hexabromobiphenyl, and 4 perfluorochemicals (PFCs). RESULTS: Older adults (those born before 1976) had baseline levels of PCBs, OCPs, and PFCs that were two- to fivefold higher than younger adults (those born after 1976). Older adults had greater increases in PCBs, OCPs, and polybrominated diphenyl ethers associated with weight loss. Conversely, younger adults had greater increases in PFCs associated with weight loss. On average, blood POP levels increased as weight loss occurred. CONCLUSIONS: Although weight loss is considered beneficial, the release and redistribution of POPs to other lipid-rich organs such as the brain, kidneys, and liver warrant further investigation. Interventions should be considered to limit organ exposure to POPs when weight loss interventions are planned.


Assuntos
Tecido Adiposo/metabolismo , Cirurgia Bariátrica , Poluentes Ambientais/sangue , Poluentes Ambientais/farmacocinética , Obesidade Mórbida/cirurgia , Tecido Adiposo/química , Adulto , Fatores Etários , Análise Química do Sangue , Exposição Ambiental/análise , Poluentes Ambientais/análise , Feminino , Seguimentos , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/sangue , Éteres Difenil Halogenados/farmacocinética , Humanos , Hidrocarbonetos Clorados/análise , Hidrocarbonetos Clorados/sangue , Hidrocarbonetos Clorados/farmacocinética , Fígado/química , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/sangue , Obesidade Mórbida/metabolismo , Praguicidas/análise , Praguicidas/sangue , Praguicidas/farmacocinética , Bifenilos Policlorados/análise , Bifenilos Policlorados/sangue , Bifenilos Policlorados/farmacocinética , Período Pós-Operatório , Distribuição Tecidual , Perda de Peso/fisiologia
4.
Environ Pollut ; 255(Pt 1): 113159, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31541817

RESUMO

Elucidation of the relationship between the levels of 35 individual dioxins and polychlorinated biphenyl congeners in environmental samples (pine needles, leaves, grass and soil), and their bioaccumulation in the muscles of two game animal families (Cervidae and Suidae) was the aim of the research. Comparative studies were performed in four industrially degraded regions with various types of heavy industry and in an agricultural region with a tourism industry. The content of pollutants was determined by the isotopic dilution method using high resolution gas chromatography coupled with high resolution mass spectrometry. The polychlorinated dibenzodioxins/furan and PCB profiles in plants, soil and animal tissues varied by region and were related to the indigenous industry. The presence of characteristic congeners of particular industrial sectors was found. The animal tissue congeners were a reflection of the types and levels found in soil and plants. Independently of the region, deer tissue had almost twice the concentration of PCDD/F/DL-PCBs compared to boars, but the converse was true for NDL-PCBs. Spearman's statistical test showed strong correlations between pine needle, leaf, grass and soil dioxin and dioxin-like PCB levels and concentrations of these in the tissues of both species. Coefficients of bioaccumulation in deer muscles (BAF) calculated for all regions varied considerably and they were significantly higher for wild boars. BAF decreased with increasing number of chlorine atoms in the dioxin and furan molecule. The highest congener values were for 2,3,7,8-tetrachlorodibenzodioxin, 1,2,3,7,8-pentachlorodibenzodioxin, 2,3,7,8-tetrachlorodibenzofuran and 2,3,4,7,8-pentachlorodibenzofuran in both kinds of muscle regardless of the region. The levels of pollutants, types of pollutants, and their relative abundance in tissues of deer and boar reflected their surrounding environment and local pollutant emitters.


Assuntos
Bioacumulação/fisiologia , Dibenzofuranos Policlorados/análise , Dibenzofuranos Policlorados/farmacocinética , Dioxinas/análise , Dioxinas/farmacocinética , Poluição Ambiental/análise , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Animais , Cervos , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Furanos/análise , Cromatografia Gasosa-Espectrometria de Massas , Indústrias , Músculos/química , Dibenzodioxinas Policloradas/análise , Solo/química , Sus scrofa , Suínos
5.
Chemosphere ; 229: 500-508, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31096086

RESUMO

Dugongs (Dugong dugon) are an iconic and strictly herbivorous species. They inhabit coastal areas, which brings them in contact with urban and agricultural pollutant sources, yet their exposure and susceptibility to environmental pollutants is still largely unknown. The goal of this study was to investigate the presence of several legacy compounds such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and pesticides as well as naturally produced MeO-PBDEs in male and female dugongs from Moreton Bay (n = 24), a semi-enclosed embayment close to Australia's third largest city, Brisbane. Results show that concentrations of all investigated compounds are low in general (<120 ng/g lipid weight) and below known toxicity thresholds established for marine mammals. However, concentrations found in this study are higher or comparable to concentrations in dugongs outside Moreton Bay or in sirenians worldwide. No temporal trends for POPs from 2001 until 2012 were found for adult animals suggesting that environmental changes are only slowly reflected in dugongs. Finally, pollutant profiles in dugongs are limited to the most persistent PCBs, pesticides and PBDEs that also dominate POP profiles in other marine mammal species in general.


Assuntos
Dugong , Exposição Ambiental/análise , Poluentes Químicos da Água/análise , Animais , Baías , Monitoramento Ambiental , Feminino , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/farmacocinética , Masculino , Compostos Orgânicos/análise , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Queensland , Urbanização , Poluentes Químicos da Água/farmacocinética
6.
Xenobiotica ; 49(12): 1414-1422, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30991879

RESUMO

1. Aryl hydrocarbon receptor (AhR) ligands, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs), are endocrine disrupting chemicals associated with nonalcoholic fatty liver disease. This study documents the species-specific differences between mouse (high affinity mAhR) and human AhR (hAhR) activation by PCB congeners and Aroclor mixtures. 2. AhR activation by TCDD or PCBs 77, 81, 114, 114, 126, and 169 was measured using luciferase reporter constructs transfected into either Hepa1c1c7 mouse or HepG2 human liver cell lines. The EC50 values were lower in Hepa1c1c7 cells than HepG2 cells for all compounds tested except PCB 81. The results for TCDD and PCB 126 were validated in primary human and mouse hepatocytes by measuring CYP1A1 gene transcript levels. 3. Because humans are exposed to PCB mixtures, several mixtures (Aroclors 1254; 1260; and 1260 + 0.1% PCB126 each at 10 µg/ml) were then tested. Neither Aroclor 1254 nor Aroclor 1260 increased luciferase activity by the transfected AhR reporter construct. The Aroclor 1260 + 0.1% PCB 126 mixture induced mAhR-mediated transactivation, but not hAhR activation in cell lines. 4. In summary, significant concentration-dependent differences exist between human and mouse AhR activation by PCBs. Relative effect potencies differed, in some cases, from published toxic equivalency factors.


Assuntos
Arocloros/farmacocinética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Bifenilos Policlorados/farmacocinética , Receptores de Hidrocarboneto Arílico/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Células Cultivadas , Família 1 do Citocromo P450/genética , Relação Dose-Resposta a Droga , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Masculino , Camundongos Endogâmicos C57BL , Bifenilos Policlorados/administração & dosagem , Receptores de Hidrocarboneto Arílico/genética , Especificidade da Espécie
7.
Mar Pollut Bull ; 139: 263-269, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30686427

RESUMO

Persistent organic pollutants (POPs) include polychlorinated biphenyls (PCBs) dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB), which are resistant to biodegradation and therefore accumulate in the marine environment. In Australia, POPs occur in high concentrations primarily in costal water near farming regions and urban centres. From contaminated sediments and biota, POPs are transferred and biomagnified in larger marine organisms. We quantified POPs concentrations in 57 individuals from ten species of sharks and rays caught in bather-protection gillnets deployed off northern New South Wales, Australia. Polychlorinated biphenyls, DDTs and HCB were detected in all species. For some individuals, concentrations were at levels known to have deleterious sub-lethal effects. Overall, the POP concentrations analysed in this study were comparable to those in similar species from more polluted regions, and may have negative impacts on longer-term health. Future research is warranted to investigate spatio-temporal patterns of species-specific contaminant loads and their implications.


Assuntos
Elasmobrânquios/metabolismo , Hidrocarbonetos Clorados/análise , Poluentes Químicos da Água/análise , Animais , DDT/análise , DDT/farmacocinética , Diclorodifenil Dicloroetileno/análise , Diclorodifenil Dicloroetileno/farmacocinética , Espécies em Perigo de Extinção , Monitoramento Ambiental , Feminino , Hexaclorobenzeno/análise , Hexaclorobenzeno/farmacocinética , Hidrocarbonetos Clorados/farmacocinética , Masculino , Músculos/química , New South Wales , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Poluentes Químicos da Água/farmacocinética
8.
Chemosphere ; 217: 195-203, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30415117

RESUMO

Total 22 organochlorine pesticides (OCPs) compounds and 31 polychlorinated biphenyls (PCBs) congeners in mangrove sediments and tissues (leaf, branch, root and fruit) of nine species from three Mangrove Reserves of China were studied. The mean concentrations of total DDTs, HCHs, OCPs and PCBs in sediments were 2.84, 0.06, 3.84 and 0.17 ng g-1 dw, while those in tissues were 1.85, 0.22, 9.43 and 1.61 ng g-1 dw, respectively. The elevated OCPs and PCBs levels in mangrove leaves may be caused by atmospheric sedimentation. The biota sediment accumulation factor (BSAF) values of both OCPs (mean: 3.4) and PCBs (mean: 9.9) are generally larger than one, implying mangroves' bioaccumulation and their ability to intercept pollutants. The BSAFs of PCBs in mangrove tissues were negatively correlated with the PCB congener's octanol-water partition coefficients (KOW, R = 0.58, n = 31, p < 0.001), suggesting that lower chlorinated CB congeners are more bioaccumulative in mangroves. In order to better understanding the fate of these organochlorine compounds, the cycling (including the standing accumulation, the annual absorption, the annual net retention, the annual return, and the turnover period) of OCPs and PCBs in the Mangrove Reserves were estimated, and the results indicated that mangroves are playing important roles in retaining OCPs and PCBs.


Assuntos
Avicennia/metabolismo , Hidrocarbonetos Clorados/farmacocinética , Praguicidas/farmacocinética , Bifenilos Policlorados/farmacocinética , China , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/farmacocinética
9.
Chemosphere ; 217: 1-8, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30391787

RESUMO

Ingestion of soils and house dusts is an important pathway for children's exposure to sorbed organic pollutants such as polychlorinated biphenyls (PCBs). To reduce the uncertainty of the exposure estimates, it is important to understand the extent to which chemicals desorb and become bioaccessible following ingestion. In this study we use a three compartment in vitro digestive system to model the role of soil and house dust physicochemical properties on the post ingestion bioaccessibility of PCBs. Matched pairs (n = 37) of soil and dust were characterized for percent carbon and nitrogen, pH, moisture content, and particle size distribution. They were then fortified with a mixture of 18 PCBs and processed through the assay. The percent bioaccessibility of each PCB was calculated, then modeled using individual PCB log Kow values and the soil and dust properties. The bioaccessibility of the PCBs in soil (x̄ = 65 ±â€¯16%) was greater (p < 0.001) than that of the PCBs in house dust (x̄ = 36 ±â€¯14%). In the soil model, carbon was the sole statistically significant predictive (p ≤ 0.05) variable, while in house dust, both carbon and clay content were statistically significant (p ≤ 0.05) predictors.


Assuntos
Poeira , Ingestão de Alimentos , Exposição Ambiental , Bifenilos Policlorados/farmacocinética , Solo , Disponibilidade Biológica , Poeira/análise , Poluentes Ambientais/análise , Poluentes Ambientais/química , Humanos , Modelos Teóricos , Bifenilos Policlorados/análise , Solo/química
10.
Mar Pollut Bull ; 136: 533-546, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30509839

RESUMO

Persistent organic pollutants (POPs) are of great concern for the environment. In this study we (a) determine levels and distribution of OCPs, PCBs, and PBDEs in sediments and two crab species (Neohelice granulata and Cyrtograpsus altimanus), (b) assess bioaccumulation in crabs, and (c) explore the occurrence of POPs in the Near Threatened Olrog's gull (Larus atlanticus) chicks and eggs in one of the most important salt marsh environments in the South West Atlantic. Sediments, crabs, and gull chicks and eggs showed POPs presence at low levels; being α-endosulfan, PCB-153, and BDE-47 the most represented compounds. In sediments, pollutant concentrations were lower than those reported in Canadian guidelines for the protection of the aquatic life. POP bioaccumulation was recorded in crabs, suggesting a risk to upper trophic level predators. Further studies are needed to understand the trophic effects of POPs in San Blas bay, particularly on the threatened Olrog's gull.


Assuntos
Braquiúros/química , Charadriiformes , Poluentes Químicos da Água/análise , Animais , Argentina , Ecotoxicologia , Espécies em Perigo de Extinção , Endossulfano/análise , Endossulfano/farmacocinética , Sedimentos Geológicos/análise , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/farmacocinética , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinética , Áreas Alagadas , Zigoto/química
11.
Environ Pollut ; 243(Pt A): 152-162, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30172121

RESUMO

This study evaluated the effect of growth of different tissue compartments on the bioaccumulation of mercury (Hg) and polychlorinated biphenyls (PCBs) in Silver Carp (Hypophthalmichthys molitrix) and Bighead Carp (Hypophthalmichthys nobilis) from the Three Gorges Reservoir (TGR), China. A non-steady state bioenergetics/toxicokinetic model was developed to simulate PCB and Hg concentrations in these two species and compared with field data. Simulations using constant whole body growth rate and constant tissue to whole body weight ratios were contrasted against simulations adopting age specific whole body and tissue/age specific growth rates for their goodness of fit to field data. The simulations using age/tissue specific growth rates demonstrated better fit to field data for PCBs compared to the constant growth rate models (22% improved R2), while both models explained similar variation in Hg concentration data. Both species demonstrated higher growth rates of lipids (on a daily basis) relative to whole body and protein contributing to higher growth dilution of PCBs compared to Hg. Although stable isotope data indicated some degree of diet and/or habitat shift, simulations assuming a constant diet concentration explained between 36 and 40% of the variation in fish concentrations for both contaminants and fish species. This study demonstrates that differences in the bioaccumulation rate of PCBs and Hg by Asian carp can be partially explained by differences in the growth rates of key tissue storage compartments associated with each contaminant. These differences in chemical-specific growth dilution subsequently contribute to differences in chemical retention and bioaccumulation patterns of Hg and PCBs by fish.


Assuntos
Carpas/crescimento & desenvolvimento , Carpas/metabolismo , Mercúrio/farmacocinética , Bifenilos Policlorados/farmacocinética , Poluentes Químicos da Água/farmacocinética , Abastecimento de Água , Água/química , Fatores Etários , Animais , China , Simulação por Computador , Modelos Biológicos , Distribuição Tecidual
12.
Mar Pollut Bull ; 131(Pt A): 174-179, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29886934

RESUMO

Two Guillemot carcases were dissected, each providing 12 discrete tissue samples and 3 samples of partially digested food. One hundred and five PCBs from the 209 PCBs determined by GCxGC-ToFMS were detected. The relative proportions of individual PCBs did not vary greatly within tissue types, although the PCB profile from undigested food could be distinguished. Enantiomer fractions (EFs) were determined for CB-95, CB-136 and CB-149 by GC-HRqToFMS. EFs in the partially digested food were near racemic, with high levels of enrichment for E1 CB-95 in the kidneys and liver (EF of 0.80 and 0.84 respectively). This provides some of the clearest evidence to date that fractionation takes place in the organs where metabolic biotransformation and elimination of PCBs occurs. Our findings also confirm the ability of non-lethal sampling techniques, such as collection of small (<1 g) blood samples, to provide PCB signatures that are representative of an individual organism.


Assuntos
Aves/metabolismo , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Animais , Biotransformação , Bifenilos Policlorados/química , Estereoisomerismo , Distribuição Tecidual , Reino Unido , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/farmacocinética
13.
Environ Pollut ; 240: 670-682, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29775944

RESUMO

Environmental chemicals originating from human activities, such as persistent organic pollutants (POPs), may interfere with the endocrine system of aquatic organisms. The effect of these chemicals on biota and human populations is of high public concern but remains poorly understood, especially in aquatic environments of South America. The aim of this study was to investigate the bioavailability of POPs and the related effects in caged male tilapia (Oreochromis niloticus) in four cascading reservoirs of the Iguaçu River, Southern Brazil. POPs including organochlorine pesticides (OCPs), polychlorinated biphenyl (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in the reservoir water and tissue samples of tilapia after two months of exposure. The PCB levels in water (14.7 ng L-1) were 14 times higher than the limits permitted by the Brazilian legislation in the Salto Santiago (SS) reservoir. Similarly, concentrations of aldrin and its metabolites (6.05 ng L-1) detected in the water sample of the Salto Osório (SO) reservoir were also above the permitted limits. RT-qPCR analysis revealed different transcript levels of cytochrome P450 enzymes (CYP1A and CYP3A) in the liver among the four groups, with induced activity in tilapia from the SS reservoir. Quantification of the CYP3A mRNA expression and catalytic activity showed higher values for fish caged at the SS reservoir. The fish from this site also had a higher number of eosinophils observed in the testes. Although overt measurements of endocrine disruption were not observed in caged fish, alteration of CYP enzymes with co-occurrence of organochlorine contaminants in water may suggest bioavailability of contaminants from agricultural sources to biota. Additional studies with feral or caged animals for a longer duration may be necessary to evaluate the risks of the waterways to humans and wildlife.


Assuntos
Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP3A/metabolismo , Disruptores Endócrinos/farmacocinética , Fígado/metabolismo , Praguicidas/farmacocinética , Tilápia/metabolismo , Poluentes Químicos da Água/farmacocinética , Animais , Disponibilidade Biológica , Brasil , Disruptores Endócrinos/análise , Peixes , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/farmacocinética , Humanos , Hidrocarbonetos Clorados/análise , Hidrocarbonetos Clorados/farmacocinética , Masculino , Praguicidas/análise , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Rios/química , Poluentes Químicos da Água/análise
14.
Chemosphere ; 203: 179-187, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29614411

RESUMO

A bench scale study was conducted to evaluate the effectiveness of in situ amendments to reduce the bioavailability of pollutants in sediments from a site impacted with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and cadmium. The amendments tested included fine and coarse coal-based activated carbons (AC), an enhanced pinewood derived biochar (EPB), organoclay, and coke dosed at 5% of sediment dry weight. Strong reductions in total PCB porewater concentrations were observed in sediments amended with the fine AC (94.9-99.5%) and EPB (99.6-99.8%). More modest reductions were observed for the coarse AC, organoclay, and coke. Strong reductions in porewater PCB concentrations were reflected in reductions in total PCB bioaccumulation in fresh water oligochaetes for both the fine AC (91.9-96.0%) and EPB (96.1-96.3%). Total PAH porewater concentrations were also greatly reduced by the fine AC (>96.1%) and EPB (>97.8%) treatments. EPB matched or slightly outperformed the fine AC throughout the study, despite sorption data indicating a much stronger affinity of PCBs for the fine AC. Modeling EPB and fine AC effectiveness on other sediments confirmed the high effectiveness of the EPB was due to the very low final porewater concentrations and differences in the native bioavailability between sediments. However, low bulk density and poor settling characteristics make biochars difficult to apply in an aquatic setting. Neither the EPB nor the fine AC amendments were able to significantly reduce Cd bioavailability.


Assuntos
Carvão Vegetal/farmacocinética , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Disponibilidade Biológica , Cádmio/análise , Cádmio/farmacocinética , Coque , Água Doce , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/farmacocinética , Poluentes Químicos da Água/farmacocinética
15.
Arch Environ Contam Toxicol ; 75(2): 295-305, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29550936

RESUMO

Determining the biotransformation potential of commercial chemicals is critical for estimating their persistence in the aquatic environment. In vitro systems are becoming increasingly important as screening methods for assessing the potential for chemical metabolism. Depletion rate constants (kd) for several organic chemicals with high octanol-water partition coefficient (Kow) values (9-methylanthracene, benzo(a)pyrene, chrysene, and PCB-153) in rainbow trout hepatocytes were determined to estimate biotransformation rate constants (kMET) that were used in fish bioconcentration factor (BCF) models. Benzo[a]pyrene was rapidly biotransformed when incubated singly; however, its depletion rate constant (kd) declined 79% in a mixture of all four chemicals. Chrysene also exhibited significant biotransformation and its depletion rate constant declined by 50% in the mixture incubation. These data indicate that biotransformation rates determined using single chemicals may overestimate metabolism in environments containing chemical mixtures. Incubations with varying cell concentrations were used to determine whether cell concentration affected kd estimates. No statistically significant change in depletion rate constants were seen, possibly due to an increase in nonspecific binding of hydrophobic chemicals as cell density increased, decreasing overall biotransformation. A new model was used to estimate BCFs from kMET values calculated from empirically derived kd values. The inclusion of kMET in models resulted in significantly lower BCF values (compared kMET = 0). Modelled BCF values were consistent with empirically derived BCF values from the literature.


Assuntos
Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Oncorhynchus mykiss , Compostos Orgânicos/química , Compostos Orgânicos/farmacocinética , Animais , Antracenos , Benzo(a)pireno/farmacocinética , Biotransformação , Crisenos/farmacocinética , Interações Hidrofóbicas e Hidrofílicas , Masculino , Bifenilos Policlorados/farmacocinética , Poluentes Químicos da Água/química , Poluentes Químicos da Água/farmacocinética
16.
Arch Environ Contam Toxicol ; 74(2): 305-317, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29164278

RESUMO

We examined the degree of exposure of lead (Pb), mercury (Hg), and several organohalogen contaminants and its potential impact on survival of bald eagles in Ontario from 1991 to 2008. Overall, results for 43 dead or dying bald eagles collected in the province indicate that 23% (10/43) of birds died of Pb poisoning and 9% (4/43) died of suspected Hg poisoning. Pb poisoning was diagnosed based on exceedances of toxicity thresholds in liver and kidney and supported by clinical observations, necropsy results, and histology findings when available. Evidence for Hg poisoning in eagles was limited; however, Hg concentrations exceeded the toxicity threshold in kidney. Pb concentrations ranged widely in liver and kidney. Total Hg concentrations were relatively higher in kidney compared with liver and were significantly correlated with selenium (Se) concentrations in both tissues. Concentrations of p,p'-DDE and sum PCBs in livers of 12 bald eagles collected from 2001 to 2004 were likely below concentrations associated with adverse effects. Hepatic concentrations of total polybrominated diphenyl ethers were generally higher in birds collected from southern Ontario compared with northern Ontario. Potential impacts of exposure to these flame retardants and others are not known. Elevated metal exposure appears to influence survivorship and may affect the recovery of bald eagles in the province, particularly in southern Ontario and along the Great Lakes where a disproportionate number of poisoned eagles were collected. Increased efforts are needed to identify sources of exposure and develop measures to reduce metal exposure in this top predator.


Assuntos
Águias/fisiologia , Exposição Ambiental/análise , Poluentes Ambientais/análise , Metais/análise , Animais , Diclorodifenil Dicloroetileno/análise , Monitoramento Ambiental/métodos , Retardadores de Chama/análise , Retardadores de Chama/farmacocinética , Hidrocarbonetos Clorados/análise , Hidrocarbonetos Clorados/farmacocinética , Rim/química , Fígado/química , Masculino , Mercúrio/análise , Metais/farmacocinética , Ontário , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Selênio/análise , Distribuição Tecidual
17.
Arch Toxicol ; 92(3): 1225-1247, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29164306

RESUMO

Migration of neural crest cells (NCC) is a fundamental developmental process, and test methods to identify interfering toxicants have been developed. By examining cell function endpoints, as in the 'migration-inhibition of NCC (cMINC)' assay, a large number of toxicity mechanisms and protein targets can be covered. However, the key events that lead to the adverse effects of a given chemical or group of related compounds are hard to elucidate. To address this issue, we explored here, whether the establishment of two overlapping structure-activity relationships (SAR)-linking chemical structure on the one hand to a phenotypic test outcome, and on the other hand to a mechanistic endpoint-was useful as strategy to identify relevant toxicity mechanisms. For this purpose, we chose polychlorinated biphenyls (PCB) as a large group of related, but still toxicologically and physicochemically diverse structures. We obtained concentration-dependent data for 26 PCBs in the cMINC assay. Moreover, the test chemicals were evaluated by a new high-content imaging method for their effect on cellular re-distribution of connexin43 and for their capacity to inhibit gap junctions. Non-planar PCBs inhibited NCC migration. The potency (1-10 µM) correlated with the number of ortho-chlorine substituents; non-ortho-chloro (planar) PCBs were non-toxic. The toxicity to NCC partially correlated with gap junction inhibition, while it fully correlated (p < 0.0004) with connexin43 cellular re-distribution. Thus, our double-SAR strategy revealed a mechanistic step tightly linked to NCC toxicity of PCBs. Connexin43 patterns in NCC may be explored as a new endpoint relevant to developmental toxicity screening.


Assuntos
Crista Neural/efeitos dos fármacos , Bifenilos Policlorados/química , Bifenilos Policlorados/toxicidade , Relação Estrutura-Atividade , Animais , Disponibilidade Biológica , Movimento Celular/efeitos dos fármacos , Conexina 43/metabolismo , Junções Comunicantes/efeitos dos fármacos , Humanos , Camundongos , Células NIH 3T3 , Crista Neural/citologia , Bifenilos Policlorados/farmacocinética , Imagem com Lapso de Tempo
18.
Sci Total Environ ; 610-611: 402-411, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28806556

RESUMO

In addition to eating contaminated prey, sea turtles may be exposed to persistent organic pollutants (POPs) from ingesting plastic debris that has absorbed these chemicals. Given the limited knowledge about POPs in pelagic sea turtles and how plastic ingestion influences POP exposure, our objectives were to: 1) provide baseline contaminant levels of three species of pelagic Pacific sea turtles; and 2) assess trends of contaminant levels in relation to species, sex, length, body condition and capture location. In addition, we hypothesized that if ingesting plastic is a significant source of POP exposure, then the amount of ingested plastic may be correlated to POP concentrations accumulated in fat. To address our objectives we compared POP concentrations in fat samples to previously described amounts of ingested plastic from the same turtles. Fat samples from 25 Pacific pelagic sea turtles [2 loggerhead (Caretta caretta), 6 green (Chelonia mydas) and 17 olive ridley (Lepidochelys olivacea) turtles] were analyzed for 81 polychlorinated biphenyls (PCBs), 20 organochlorine pesticides, and 35 brominated flame-retardants. The olive ridley and loggerhead turtles had higher ΣDDTs (dichlorodiphenyltrichloroethane and metabolites) than ΣPCBs, at a ratio similar to biota measured in the South China Sea and southern California. Green turtles had a ratio close to 1:1. These pelagic turtles had lower POP levels than previously reported in nearshore turtles. POP concentrations were unrelated to the amounts of ingested plastic in olive ridleys, suggesting that their exposure to POPs is mainly through prey. In green turtles, concentrations of ΣPCBs were positively correlated with the number of plastic pieces ingested, but these findings were confounded by covariance with body condition index (BCI). Green turtles with a higher BCI had eaten more plastic and also had higher POPs. Taken together, our findings suggest that sea turtles accumulate most POPs through their prey rather than marine debris.


Assuntos
Tecido Adiposo/química , Compostos Orgânicos/farmacocinética , Plásticos , Tartarugas , Animais , California , China , Ingestão de Alimentos , Monitoramento Ambiental , Retardadores de Chama/farmacocinética , Hidrocarbonetos Clorados/farmacocinética , Oceano Pacífico , Bifenilos Policlorados/farmacocinética , Resíduos
19.
Arch Environ Contam Toxicol ; 74(3): 361-371, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28601932

RESUMO

Current methods for evaluating exposure in ecosystems contaminated with hydrophobic organic contaminants typically focus on sediment exposure. However, a comprehensive environmental assessment requires a more holistic approach that not only estimates sediment concentrations, but also accounts for exposure by quantifying other pathways, such as bioavailability, bioaccumulation, trophic transfer potential, and transport of hydrophobic organic contaminants within and outside of the aquatic system. The current study evaluated the ability of multiple metrics to estimate exposure in an aquatic ecosystem. This study utilized a small lake contaminated with polychlorinated biphenyls (PCBs) to evaluate exposure to multiple trophic levels as well as the transport of these contaminants within and outside of the lake. The PCBs were localized to sediments in one area of the lake, yet this area served as the source of PCBs to aquatic invertebrates, emerging insects, and fish and terrestrial spiders in the riparian ecosystem. The Tenax extractable and biota PCB concentrations indicated tissue concentrations were localized to benthic invertebrates and riparian spiders in a specific cove. Fish data, however, demonstrated that fish throughout the lake had PCB tissue concentrations, leading to wider exposure risk. The inclusion of PCB exposure measures at several trophic levels provided multiple lines of evidence to the scope of exposure through the aquatic and riparian food web, which aids in assessing risk and developing potential future remediation strategies.


Assuntos
Ecotoxicologia/métodos , Exposição Ambiental/análise , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Animais , Biota , Ecossistema , Peixes , Cadeia Alimentar , Sedimentos Geológicos/química , Illinois , Insetos , Invertebrados , Lagos , Bifenilos Policlorados/farmacocinética , Bifenilos Policlorados/toxicidade , Aranhas , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade
20.
Environ Sci Technol ; 51(18): 10536-10545, 2017 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-28876910

RESUMO

We report on two farms in Switzerland heavily contaminated by polychlorinated biphenyls (PCBs) and dioxins (PCDD/Fs), occurring in the first case from diffuse sources and in the second case from PCB-containing wall paint. Extensive measurements of PCBs and PCDD/Fs on site (soil, forage, and paint) and in cattle (blood, fat, and milk) allowed validation of our novel dynamic toxicokinetic model, which includes the transfer of contaminants from the mother cows to their suckling calf and the uptake of soil by grazing cattle. We show that for calves, the mother milk is the main uptake route of contaminants. For both cows and calves, ingestion of contaminated soil, although often overlooked, is an appreciable uptake path. The remediation of the contaminated stable lead to a 2-3 fold reduction of the PCB levels in animals within one year. The transfer of animals to an uncontaminated mountain site during summer proved to be an effective decontamination procedure with up to 50% reduction of the levels within three months. Our study calls for a rapid removal of PCB-containing materials in animal husbandry farms and shows that the diffuse contamination of soils will remain a source for PCBs and PCDD/Fs in our food chain for decades to come.


Assuntos
Dioxinas/química , Furanos/química , Bifenilos Policlorados/química , Poluentes do Solo/química , Criação de Animais Domésticos , Animais , Benzofuranos , Bovinos , Dioxinas/farmacocinética , Feminino , Cadeia Alimentar , Furanos/farmacocinética , Lactação , Bifenilos Policlorados/farmacocinética , Dibenzodioxinas Policloradas , Poluentes do Solo/farmacocinética , Suíça
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