Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Environ Sci Technol ; 58(15): 6772-6780, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38577774

RESUMO

The quality of chemical analysis is an important aspect of passive sampling-based environmental assessments. The present study reports on a proficiency testing program for the chemical analysis of hydrophobic organic compounds in silicone and low-density polyethylene (LDPE) passive samplers and hydrophilic compounds in polar organic chemical integrative samplers. The median between-laboratory coefficients of variation (CVs) of hydrophobic compound concentrations in the polymer phase were 33% (silicone) and 38% (LDPE), similar to the CVs obtained in four earlier rounds of this program. The median CV over all rounds was 32%. Much higher variabilities were observed for hydrophilic compound concentrations in the sorbent: 50% for the untransformed data and a factor of 1.6 after log transformation. Limiting the data to the best performing laboratories did not result in less variability. Data quality for hydrophilic compounds was only weakly related to the use of structurally identical internal standards and was unrelated to the choice of extraction solvent and extraction time. Standard deviations of the aqueous concentration estimates for hydrophobic compound sampling by the best performing laboratories were 0.21 log units for silicone and 0.27 log units for LDPE (factors of 1.6 to 1.9). The implications are that proficiency testing programs may give more realistic estimates of uncertainties in chemical analysis than within-laboratory quality control programs and that these high uncertainties should be taken into account in environmental assessments.


Assuntos
Polietileno , Poluentes Químicos da Água , Polietileno/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Compostos Orgânicos , Silicones
2.
Bioorg Chem ; 124: 105793, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35462234

RESUMO

Non-psychotropic cannabinoids (e.g., cannabidiol, cannabinol and cannabigerol) are contained in numerous alimentary and medicinal products. Therefore, predicting and studying their possible side effects, such as changes in DNA methylation, is an important task for assessing the safety of these products. Interference with TET enzymes by chelating ferrous ions can contribute to the altered methylation pattern. All tested cannabinoids displayed a strong affinity for Fe(II) ions. Cannabidiol and cannabinol exhibited potent inhibitory activities (IC50 = 4.8 and 6.27 µM, respectively) towards the TET1 protein, whereas cannabigerol had no effect on the enzyme activity. An in silico molecular docking study revealed marked binding potential within the catalytic cavity for CBD/CBN, but some affinity was also found for CBG, thus the total lack of activity remains unexplained. These results imply that cannabinoids could affect the activity of the TET1 protein not only due to their affinity for Fe(II) but also due to other types of interactions (e.g., hydrophobic interactions and hydrogen bonding).


Assuntos
Canabidiol , Canabinoides , Cannabis , Canabidiol/química , Canabidiol/farmacologia , Canabinoides/farmacologia , Canabinol/farmacologia , Cannabis/química , Compostos Ferrosos , Simulação de Acoplamento Molecular
3.
ScientificWorldJournal ; 2014: 918097, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24616653

RESUMO

This study investigated polycyclic aromatic hydrocarbons (PAH) pollution of selected rivers in the Czech Republic. Integrated evaluation was carried out using combination of chemical and biological monitoring, in which we measured content of 1-hydroxypyrene (1-OHP) in chub bile and priority PAH in water samples obtained by exposing the semipermeable membrane devices at each location. The concentrations of 1-OHP in bile samples and sum of priority PAH in water sampler ranged from 6.8 ng mg protein(-1) to 106.6 ng mg protein(-1) and from 5.2 ng L(-1) to 173.9 ng L(-1), respectively. The highest levels of biliary metabolite and PAH in water were measured at the Odra River (the Bohumín site), which is located in relatively heavily industrialized and polluted region. Statistically significant positive correlation between biliary 1-OHP and sum of PAH in water was also obtained (P < 0.01, r s = 0.806).


Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , Rios/química , Poluentes Químicos da Água/análise , Animais , Cyprinidae , República Tcheca , Geografia , Humanos , Masculino
4.
Aquat Toxicol ; 150: 83-92, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24658013

RESUMO

The freshwater mudsnail (Potamopyrgus antipodarum) is sensitive to toxicity of both sediment and water and also to the endocrine disrupting compounds (EDC) at environmentally relevant concentrations. This study determined effects of in situ exposure of P. antipodarum as a part of a complex assessment of the impact of a city metropolitan area with large waste water treatment plant (WWTP) for 0.5 million population equivalents on two urban rivers. The study combined the in situ biotest with detailed chemical analyses and a battery of in vitro bioassays of both sediment and water. Passive sampling of river water was conducted during the course of exposure of the mudsnail. P. antipodarum was exposed for 8 weeks in cages permeable to sediment and water at localities up- and down-stream of the city of Brno, Czech Republic and downstream of the WWTP in two rivers. Greater mortality and significantly decreased embryo production of P. antipodarum were observed immediately downstream of the city of Brno. P. antipodarum exposed at locations downstream of the metropolitan area and WWTP exhibited greater mortality, while numbers of embryos produced by surviving individuals were comparable or slightly greater than for individuals held at the least polluted location. Comparisons with results of chemical analysis and in vitro assays indicate occurrence of groups of compounds contributing to observed effects. Differences in mortalities of mudsnails among sites corresponded well with in vitro cytotoxicity and concentrations of metals. The results of this study confirm the applicability of this novel field biotest with P. antipodarum for the evaluation of the effects of river pollution on metazoans, especially as suitable in situ part of integrative contamination assessment.


Assuntos
Monitoramento Ambiental , Caramujos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Linhagem Celular Tumoral , Sedimentos Geológicos/química , Humanos , Concentração Inibidora 50 , Mortalidade , Reprodução/efeitos dos fármacos , Rios/química , Análise de Sobrevida , População Urbana , Poluentes Químicos da Água/análise
5.
Environ Sci Process Impacts ; 16(3): 369-73, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24390685

RESUMO

The following provides a short overview of the important topics arising from the 6(th) International Passive Sampling Workshop and Symposium (IPSW 2013) held in Bordeaux, France between 26 and 29(th) June, 2013. Most of the discussions focussed on monitoring non-polar and polar organic pollutants in water with less coverage on air (probably already seen as a mature technology for this medium) and sediments. The use of passive sampling devices within regulatory water monitoring programmes was also a major theme of the Workshop.


Assuntos
Monitoramento Ambiental/instrumentação , Poluentes Ambientais/análise , Monitoramento Ambiental/métodos , Política Ambiental , Poluição Ambiental/estatística & dados numéricos
6.
Artigo em Inglês | MEDLINE | ID: mdl-24108222

RESUMO

BACKGROUND: [corrected] Deep skin burn injuries, especially those on the face, hands, feet, genitalia and perineum represent significant therapeutic challenges. Autologous dermo-epidermal skin grafts (DESG) have become standard of care for treating deep burns. Additionally, human autologous thrombin activated autologous platelet concentrate (APC) has gained acceptance in the setting of wounds. While each of these interventions has been independently shown to accelerate healing, the combination of the two has never been evaluated. We hypothesized that the addition of platelets (source of growth factors and inhibitors necessary for tissue repair) to the DESG (source of progenitor cells and of tissue proteases necessary for spatial and temporal control of growth regulators released from platelets) would create the optimal environment for the reciprocal interaction of cells within the healing tissues. METHODS: We used clinical examination (digital photography), standardised scales for evaluating pain and scarring, in combination with blood perfusion (laser Doppler imaging), as well as molecular and laboratory analyses. RESULTS: We show for the first time that the combination of APC and DESG leads to earlier relief of pain, and decreased use of analgesics, antipruritics and orthotic devices. Most importantly, this treatment is associated with earlier discharges from hospital and significant cost savings. CONCLUSIONS: Our findings indicate that DESG engraftment is facilitated by the local addition of platelets and by systemic thrombocytosis. This local interaction leads to the physiological revascularization at 1-3 months. We observed significant elevation of circulating platelets in early stages of engraftment (1-7 days), which normalized over the subsequent 7 and 90 days.


Assuntos
Queimaduras/terapia , Cicatriz/prevenção & controle , Plasma Rico em Plaquetas , Transplante de Pele/métodos , Queimaduras/diagnóstico por imagem , Queimaduras/cirurgia , Cicatriz/cirurgia , Feminino , Humanos , Fluxometria por Laser-Doppler , Masculino , Pessoa de Meia-Idade , Dor/tratamento farmacológico , Dor/etiologia , Medição da Dor , Prurido/tratamento farmacológico , Prurido/etiologia , Reoperação , Transplante de Pele/efeitos adversos , Ultrassonografia , Cicatrização
7.
J Environ Monit ; 14(1): 250-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22089646

RESUMO

Sulfonamide antibiotics coming from both human and veterinary medicine are among the most common emerging pollutants in freshwater. The present paper shows the successful application of passive sampling using POCIS in combination with an immunochemical ELISA technique and HPLC/MS/MS analysis to study the distribution of sulfonamides in streams around small towns in the Czech Republic, as well as around a major agglomeration of the city of Brno, including its waste water treatment plant (WWTP). Results indicated the presence of sulfonamides at most studied sites with concentrations ranging from <20 up to 736 ng of sulfamethoxazole equivalents per POCIS. Very high levels were detected in both the influent and effluent of the Brno WWTP with maxima > 8000 ng SMX per POCIS. All samplers collected down-stream of the studied towns and WWTPs clearly showed an increase in sulfonamide drug residues. Higher concentrations were determined in rivers at the city of Brno agglomeration. In agreement with other available studies, these findings indicate low efficiency of conventional WWTPs to eliminate polar pharmaceuticals such as sulfonamides. Good performance and correlation with the LC/MS results, as well as ease of use, indicate good potential for the immunochemical ELISA technique to become the screening tool for sulfonamide determination in surface waters including passive samplers.


Assuntos
Antibacterianos/análise , Monitoramento Ambiental/métodos , Sulfonamidas/análise , Poluentes Químicos da Água/análise , República Tcheca , Ensaio de Imunoadsorção Enzimática , Eliminação de Resíduos Líquidos/métodos , Poluição Química da Água/estatística & dados numéricos
8.
J Environ Monit ; 13(11): 2979-82, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22008796

RESUMO

Passive sampling devices have been used since the 1970s to measure time-weighted average (TWA) or equilibrium concentrations of pollutants in various environmental matrices (e.g. air, soils and sediments and water). In recent years the popularity of using such samplers has increased and the technology in now well established for the measurement of atmospheric pollutants. This sector has a long experience of using passive samplers in the short- and long-term assessment of air quality in the local environment and on a global scale (e.g. within the United Nations Stockholm Convention on the trans-boundary movement of persistent organic pollutants (POPs) where large networks of samplers on a continental scale have been established). In comparison, the use of passive samplers for monitoring the aquatic environment has been slower to take off. There has, however, been a recent research drive to develop devices for measuring the wide range of pollutants that can be found in environmental waters (e.g. ground, surface, and marine). It is now being recognised that passive samplers can play a valuable role in monitoring water quality within a legislative framework such as the European Union's Water Framework Directive (WFD). The data from these devices can be used alongside the results obtained from conventional spot or bottle sampling to improve risk assessments and to inform decisions on undertaking potentially expensive remedial actions. Such monitoring techniques may have uses within the European Registration, Evaluation, Authorisation & restriction of CHemicals (REACH) Directive and the forthcoming European Marine Strategy Directive. It is expected that the aquatic monitoring sector will follow a transition similar to that which occurred in air monitoring where data obtained from passive samplers can use used within a legal framework. There has also been increased interest in extending the role of passive samplers to both the measurement of equilibrium concentrations and investigating the movement and release of the dissolved fraction of various pollutants in the pore water of sediments and soils.


Assuntos
Monitoramento Ambiental/instrumentação , Poluentes da Água/análise , Calibragem , Monitoramento Ambiental/métodos , Monitoramento Ambiental/normas , União Europeia , Variações Dependentes do Observador
9.
Environ Sci Technol ; 45(21): 9427-34, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21932830

RESUMO

This study reports on the first complex data set of emission factors (EFs) of selected pollutants from combustion of five fuel types (lignite, bituminous coal, spruce, beech, and maize) in six different domestic heating appliances of various combustion designs. The effect of fuel as well as the effect of boiler type was studied. In total, 46 combustion runs were performed, during which numerous EFs were measured, including the EFs of particulate matter (PM), carbon monoxide, polyaromatic hydrocarbons (PAH), hexachlorobenzene (HxCBz), polychlorinated dibenzo-p-dioxins and furans (PCDD/F), etc. The highest EFs of nonchlorinated pollutants were measured for old-type boilers with over-fire and under-fire designs and with manual stoking and natural draft. Emissions of the above-mentioned pollutants from modern-type boilers (automatic, downdraft) were 10 times lower or more. The decisive factor for emission rate of nonchlorinated pollutants was the type of appliance; the type of fuel plays only a minor role. Emissions of chlorinated pollutants were proportional mainly to the chlorine content in fuel, but the type of appliance also influenced the rate of emissions significantly. Surprisingly, higher EFs of PCDD/F from combustion of chlorinated bituminous coal were observed for modern-type boilers (downdraft, automatic) than for old-type ones. On the other hand, when bituminous coal was burned, higher emissions of HxCBz were found for old-type boilers than for modern-type ones.


Assuntos
Poluentes Atmosféricos/análise , Fontes Geradoras de Energia , Monitoramento Ambiental , Calefação , Benzofuranos/análise , Incineração , Compostos Orgânicos/análise , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/análise , Hidrocarbonetos Policíclicos Aromáticos/análise
10.
J Environ Monit ; 13(9): 2582-7, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21811729

RESUMO

Polar organic compound integrative samplers (POCIS) in combination with instrumental techniques such as LC-MS-MS were previously used to monitor environmental pollutants but the performance of alternative immunochemical methods such as ELISA (enzyme-linked immunosorbent assay) has been explored less. In the present study, POCIS technology was applied to surface water sampling in the Czech Republic, and ELISA was used as a detection technique for the herbicide atrazine. In the first study, 28 samples from streams around small municipal waste water treatment plants (WWTPs) were collected using two different devices (POCISpest and POCISpharm) over the course of 21 days. Elevated atrazine concentrations (up to 25 ng per POCIS) were found in samples down-stream of WWTPs. This observation was also confirmed in another two year study (4 sampling periods) investigating 7 river sites around a major city of Brno as well as the inlet and outlet of the city's WWTP. High atrazine levels were systematically determined at the outlet from the WWTPs (120-605 ng per POCIS). A decreasing trend in the atrazine concentrations in rivers around the city of Brno has been observed, with the highest levels observed within the first sampling period in spring 2007 (100-600 ng per POCIS, with an extreme value of 2760 ng per POCIS). Results of the atrazine ELISA were closely correlated with LC-MS/MS, which confirmed good applicability of ELISA as a cost-effective screening tool.


Assuntos
Atrazina/análise , Monitoramento Ambiental/métodos , Água Doce/química , Poluentes Químicos da Água/análise , Monitoramento Ambiental/instrumentação , Ensaio de Imunoadsorção Enzimática , Herbicidas/análise , Poluição Química da Água/estatística & dados numéricos
11.
Environ Toxicol Chem ; 29(3): 541-9, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20821476

RESUMO

The aim of the present study is to assess aquatic ecosystem contamination using selected biochemical markers: cytochrome P450, ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), tripeptide glutathione, vitellogenin, and 11-ketotestosterone in chub (Leuciscus cephalus L.). Seven locations on the Svitava and Svratka rivers (in the Brno conurbation, Czech Republic) were assessed. The results were compared with the levels of the most important inductors of these biomarkers: organic pollutants hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), DDT and its metabolites, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons in bottom sediment, fish muscle, and semipermeable membrane devices (SPMDs) and metals in sediment. The highest levels of pollutants were observed at sites situated downstream from Brno, especially at Modrice and Rajhradice. Significant positive correlations (p < 0.05) were found between EROD activity and HCH concentration in SPMDs, and also between GST and EROD activity with HCB concentration in muscle, after adjusting for age.


Assuntos
Cyprinidae/metabolismo , Monitoramento Ambiental , Rios/química , Poluentes Químicos da Água/análise , Animais , Biomarcadores , Citocromo P-450 CYP1A1/metabolismo , República Tcheca , Disruptores Endócrinos/análise , Glutationa Transferase/metabolismo , Masculino , Compostos Orgânicos/análise , Testosterona/análogos & derivados , Testosterona/sangue , Vitelogeninas/sangue
12.
Environ Toxicol Chem ; 29(3): 550-5, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20821477

RESUMO

Endocrine-disrupting chemicals (EDC) are manmade or natural chemicals that have the ability to interfere with the endocrine system of animals. They have not been monitored systematically in the Czech Republic. The goal of the present study was the characterization of aquatic environmental pollution from the Brno (Czech Republic) city agglomeration focusing on EDC. Passive sampling devices, as well as semipermeable membrane devices (SPMD) and polar organic chemical integrative samplers (POCIS), were used for the pilot assessment of EDC. They were deployed for 21- to 28-d periods at nine locations in the Svratka and Svitava Rivers, Brno, Czech Republic, including at the inlet and outlet of Brno's wastewater treatment plant. The SPMDs were used to monitor nonpolar compounds such as polychlorinated biphenyls (PCBs), polynuclear aromatic hydrocarbons (PAHs), and organochlorinated pesticides (OCP). The POCIS were used to monitor polar compounds such as pesticides and their metabolites, perfluoro-organic compounds (PFOC), and pharmaceuticals. The passive samplers allowed very low detection limits for soluble (bioavailable) fractions of pollutants. The contribution of PAH, PCB, and HCB in sewage water to pollution of the Svratka River was low. The Brno wastewater treatment plant was identified as the main source of pharmaceuticals, triclosan, methyl triclosan, and some polar pesticides.


Assuntos
Disruptores Endócrinos/análise , Monitoramento Ambiental/métodos , Rios/química , Poluentes Químicos da Água/análise , República Tcheca , Fluorocarbonos/análise , Praguicidas/análise , Preparações Farmacêuticas/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Eliminação de Resíduos Líquidos , Purificação da Água
13.
Sensors (Basel) ; 10(1): 203-17, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-22315535

RESUMO

The aim of the present study was to assess aquatic contamination by polycyclic aromatic hydrocarbons (PAH), using the 1-hydroxypyrene (1-OHP) content in fish bile as a biochemical marker. A total of 71 chub (Leuciscus cephalus L.) were collected from seven locations on the Svitava and Svratka rivers in and around the industrial city of Brno, Czech Republic. The levels of 1-OHP were determined by reverse phase HPLC with fluorescence detection after deconjugation. Normalising the molar concentration of the biliary 1-OHP to the biliary protein content reduced sample variation. The content of 1-OHP was correlated with the PAH level in bottom sediment and semi-permeable membrane devices (SPMD), which was analyzed by a combination of HPLC/FLD and GC/MS methods. The highest mean values of 1-OHP were found in fish caught at the Svratka River at locations Modrice (169.2 ± 99.7 ng · mg(-1) protein) and Rajhradice (152.2 ± 79.7 ng · mg(-1) protein), which are located downstream from Brno. These values were significantly (P < 0.05) higher than those obtained from localities Knínicky (98.4 ± 66.1 ng · mg(-1) protein) and Bílovice nad Svitavou (64.1 ± 31.4 ng · mg(-1) protein). The lowest contents of PAH in sediment and SPMD were found at location Knínicky (1.5 mg · kg(-1) dry mass and 19.4 ng · L(-1), respectively). The highest contents of PAH in sediment and SPMD were found in Rajhradice (26.0 mg · kg(-1) dry mass) and Svitava before junction (65.4 ng · L(-1)), respectively. A Spearman correlation test was applied to determine the relationship between biliary 1-OHP and the sum of PAH in sediment and SPMD. A positive, but no statistically significant correlation was found. The main impact sources of elevated level of PAHs in sites located downstream from Brno are most probably intensive industrial and agricultural activities and domestic waste.


Assuntos
Bioensaio/métodos , Peixes/metabolismo , Hidrobiologia/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Pirenos/análise , Poluentes Químicos da Água/análise , Água/química , Animais , Bile/química , Biomarcadores/análise
14.
Neuro Endocrinol Lett ; 30 Suppl 1: 211-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20027173

RESUMO

OBJECTIVES: The study was designed to assess the pollution of the Svitava and Svratka rivers in and around the industrial city of Brno (Czech Republic) by persistent organic pollutants using selected biochemical markers in chub. DESIGN: Levels of selected biochemical markers were measured in liver and plasma samples of chub. The concentrations of persistent organic pollutants (POPs) were determined in bottom sediment, semi-permeable membrane devices (SPMDs) and muscle samples, and consequently used for correlation with biochemical markers. RESULTS: Significant alterations (p < 0.05) in some biochemical markers were observed and associated with combined exposure to pollutants. The highest levels of pollutants were found at sites situated downstream from Brno. The most widespread changes were identified in the function of phase I detoxifying enzymes. Significant positive correlations were observed in cytochrome P450 content and DDT concentration in the semi-permeable membrane device (p = 0.019, rs = 0.886), and between ethoxyresorufin-O-deethylase activity and content of DDT (p = 0.041, rs = 0.352) and polychlorinated biphenyls (p = 0.034, rs = 0.365) in muscle tissues of indicator fish. CONCLUSION: The results presented in our study indicate the highest contamination of sites situated downstream from Brno, where the intensive industrial and agricultural activities as well as domestic waste and sewage most probably comprise the main impact sources of the enhanced level of pollutants and some biochemical markers in fish.


Assuntos
Cyprinidae/metabolismo , Rios/química , Poluentes da Água/análise , Poluição da Água/análise , Animais , Biomarcadores/análise , Biomarcadores/sangue , Biomarcadores/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , República Tcheca , DDT/análise , DDT/metabolismo , Exposição Ambiental , Fígado/química , Fígado/enzimologia , Fígado/metabolismo , Masculino , Músculo Esquelético/química , Músculo Esquelético/enzimologia , Músculo Esquelético/metabolismo , Bifenilos Policlorados/análise , Bifenilos Policlorados/metabolismo , Poluentes da Água/metabolismo
16.
Neuro Endocrinol Lett ; 29(5): 663-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18987610

RESUMO

OBJECTIVES: The aim of this study was the assessment of the Svitava and Svratka rivers contamination by polycyclic aromatic hydrocarbons (PAH) using 1-hydroxypyrene (1-OHP) concentrations in fish bile as a biomarker. DESIGN: Levels of 1-OHP were determined by reverse phase HPLC with fluorescence detection. For valid assessment of bile accumulation levels, the 1-OHP concentration was normalized to the biliary protein content. The content of 1-OHP was correlated with the PAH content of river bottom sediments. RESULTS: The highest level of 1-OHP in fish bile (136.1 ng.mg-1 protein) was found at the locality Rajhradice, which is situated downstream of Brno. Also the greatest level of sum of PAHs was found at this locality (17.1 microg.g-1 dry mass). Significant positive correlation (p< or =0.05) between the level of 1-OHP and sum of PAHs in sediment was found only in case of sediments collected in the same month as fish samples (in June). CONCLUSION: Our results document that 1-OHP in fish bile is a suitable biochemical marker for the assessment of aquatic ecosystem contamination by PAHs.


Assuntos
Bile/metabolismo , Peixes/metabolismo , Mutagênicos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Pirenos/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores , Cromatografia Líquida de Alta Pressão , Cyprinidae/fisiologia , República Tcheca , Monitoramento Ambiental , Água Doce , Hidrocarbonetos Policíclicos Aromáticos/análise , Proteínas/metabolismo , Espectrometria de Fluorescência , Poluentes Químicos da Água/análise
17.
Environ Toxicol Pharmacol ; 25(2): 148-55, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21783851

RESUMO

The values of thermochemical quantities (enthalpy and Gibbs energy of formation, entropy and molar heat capacity) in the ideal gas state and dihedral angles for all 209 polychlorinated biphenyls were obtained by the Benson contribution method and ab initio calculations. The di-, tri- and tetra-ortho-chlorinated biphenyls are related with properties of WHO non-ortho- and mono-ortho-biphenyls in connection with their potential human toxicities.

18.
Environ Sci Pollut Res Int ; 14(2): 94-101, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17455818

RESUMO

GOAL, SCOPE AND BACKGROUND: The article is focused on dioxin, furan, PCB and organochlorine pesticide monitoring in the surface waters of the Central European, protected natural reserve Krivoklatsko, under the UNESCO programme Man and Biosphere. Persistent compounds are presently transported via different means throughout the entire world. This contamination varies significantly between sites. This raises the question of what constitutes the naturally occurring background levels of POPs in natural, unpolluted areas, but which are close to industrialised regions. Information of real background POP contamination can be of high value for risk assessment management of those sites evidently polluted and for the defining of de-contamination limits. Preserved areas should not be seen as isolated regions in which the impacts of human activities and natural factors are either unexpected or overlooked. Every ambient region, even those protected by a law or other means, are still closely connected to neighbouring human developed and impacted areas, and are therefore subject to this anthropogenic contamination. These areas adjacent to natural reserves are sources of diverse substances, via entry of air, water, soil and/or biota. After an extended period of industrial activities, organochlorine pollutants, even those emitted in trace concentrations have reached detectable levels. For future research and for the assessment of environmental changes, present levels of contamination would be of high importance. This work publishes data of the contamination with organochlorine pollutants of this natural region, where biodiversity and ecological functions are of the highest order. METHODS: Semipermeable membrane devices (SPMDs) were utilised as the sampling system. SPMDs were deployed in two small creeks and one water reservoir selected in the central part of the Krivoklatsko Natural Reserve, where it could be expected that any possible contamination by POPs would be lowest. The exposed SPMDs were analysed both for chemical contents of POPs and for toxicity properties. The chemical analyses of dibenzodioxins, dibenzo-furans, PCBs and OCPs were analysed by GC/MS/MS on GCQ or PolarisQ (Thermoquest). Toxicity bioassays were performed on the alga Desmodesmus subspicatus, bacteria Vibrio fischeri and crustacean Daphnia magna. All toxicity data were expressed as the effective volume Vtox. Vtox is a toxicity parameter, the determination of which is independent of SPMD deployment time and pre-treatment dilution (unlike, for example, the EC50 of the SPMD extract). RESULTS: The following chemical parameters were monitored: (1) tetra, penta, hexa and hepta dibenzo-p-dioxins and furans; (2) all those detectable from tri- through deca-polychloriated biphenyls (PCBs) and (3) a group of organochlorine pesticides: hexachlorobenzene and isomers of hexachlorocyclohexane, DDE, DDD and DDT. The concentrations of dioxins and furans on the assessed sites varied from under detection levels up to 7 pg.l(-1); PCBs were detected in a sum concentration up to 2.8 ng.l(-1); and organochlorine pesticides up to 346 pg.l(-1). The responses of bioassays used were very low, with the values obtained for Vtox being under 0.03 l/d. DISCUSSION: Toxicity testing showed no toxicity responses, demonstrating that the system used is in coherence with the ecological status of the assessed sites. Values of Vtox were under the critical value--showing no toxicity. The PCA of chemical analysis data and toxicity responses resulted in no correlations between these two groups of parameters. This demonstrated that the present level of contamination has had no direct adverse effects on the biota. CONCLUSIONS: The concentration values of six EPA-listed, toxic dioxins and sums of tetra-hepta dioxins; nine EPA toxic dibenzofurans and the sums of tetra-hepta bibenzofurans are presented together with all tri-deka PCBs and organochlorine pesticides (alfa-, beta-, gama-, delta-HCH, HCB, opDDE, ppDDE, opDDD, ppDDD, opDDT, ppDDT). These values represent possible current regional natural background values of these substances monitored within the Central European region, with no recorded adverse effects on the freshwater ecosystem (up until the present time). RECOMMENDATIONS AND PERSPECTIVES: Assessment of dioxins, furans and other organochlorine compounds within natural reserves can be important for the monitoring of human-induced impacts on preserved areas. No systematic monitoring of these substances in areas not directly affected by industry has generally been realised. There is a paucity of data of the presence of any of these substances within natural regions. Further monitoring of contamination of both soil and biota by dioxins and furans in preserve regions is needed and can be used for future monitoring of man-made activities and/or accidents. Semipermeable membrane devices proved to be a very good sampling system for the monitoring of trace concentrations of ambient organochlorine compounds. Toxicity evaluation using the Vtox concept demonstrated that those localities assessed expressed no toxicity.


Assuntos
Benzofuranos/análise , Dioxinas/análise , Hidrocarbonetos Clorados/análise , Poluentes Químicos da Água/análise , Aliivibrio fischeri/efeitos dos fármacos , Aliivibrio fischeri/metabolismo , Animais , Benzofuranos/toxicidade , República Tcheca , Daphnia/efeitos dos fármacos , Daphnia/fisiologia , Dioxinas/toxicidade , Monitoramento Ambiental/instrumentação , Feminino , Água Doce/análise , Hidrocarbonetos Clorados/toxicidade , Luminescência , Membranas Artificiais , Movimento/efeitos dos fármacos , Scenedesmus/efeitos dos fármacos , Scenedesmus/crescimento & desenvolvimento , Poluentes Químicos da Água/toxicidade , Abastecimento de Água/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA